The Effect of Micronutrients on Obese Phenotype of Adult Mice Is Dependent on the Experimental Environment

The environment of the test laboratory affects the reproducibility of treatment effects on physiological phenotypes of rodents and may be attributed to the plasticity of the epigenome due to nutrient-gene-environment interactions. Here, we explored the reproducibility of adding a multi-vitamin-mineral (MVM) mix to a nutrient-balanced high-fat (HF) diet on obesity, insulin resistance (IR), and gene expression in the tissues of adult male mice. Experiments of the same design were conducted in three independent animal facilities. Adult C57BL/6J male mice were fed an HF diet for 6 weeks (diet induced-obesity model) and then continued for 9-12 weeks on the HF diet with or without 5-fold additions of vitamins A, B1, B6, B12, Zn, and 2-fold Se. The addition of the MVM affected body weight, fat mass, gene expression, and markers of IR in all three locations (p < 0.05). However, the direction of the main effects was influenced by the interaction with the experimental location and its associated environmental conditions known to affect the epigenome. In conclusion, MVM supplementation influenced phenotypes and expression of genes related to adipose function in obese adult male mice, but the experimental location and its associated conditions were significant interacting factors. Preclinical studies investigating the relationship between diet and metabolic outcomes should acknowledge the plasticity of the epigenome and implement measures to reproduce studies in different locations.

Methyl donor micronutrients, hypothalamic development and programming for metabolic disease

Nutriture in utero is essential for fetal brain development through the regulation of neural stem cell proliferation, differentiation, and apoptosis, and has a long-lasting impact on risk of disease in offspring. This review examines the role of maternal methyl donor micronutrients in neuronal development and programming of physiological functions of the hypothalamus, with a focus on later-life metabolic outcomes. Although evidence is mainly derived from preclinical studies, recent research shows that methyl donor micronutrients (e.g., folic acid and choline) are critical for neuronal development of energy homeostatic pathways and the programming of characteristics of the metabolic syndrome in mothers and their children. Both folic acid and choline are active in one-carbon metabolism with their impact on epigenetic modification of gene expression. We conclude that an imbalance of folic acid and choline intake during gestation disrupts DNA methylation patterns affecting mechanisms of hypothalamic development, and thus elevates metabolic disease risk. Further investigation, including studies to determine translatability to humans, is required.

Micronutrients in High-Fat Diet Modify Insulin Resistance and Its Regulatory Genes in Adult Male Mice

SCOPE

Obesity and insulin resistance (IR) are associated with epigenetic changes of gene expression. However, the relationship between micronutrients, epigenetic regulation of gene expression, and IR during development of diet-induced obesity has yet to be defined. Our objective is to describe the effect of micronutrient addition to diets on IR and its related genes during obesity development.

METHODS AND RESULTS

Male C57BL/6J mice are fed a high-fat (HFD) or low-fat (LFD) diets with or without a multi-vitamin mineral mix (MVM) addition containing vitamins A, B1, B6, B12, and Zn, and Se for 9 weeks. Compared to LFD mice, HFD mice have higher body weight, IR, fasting glucose, insulin, C-peptide, leptin, and hepatic triglyceride concentrations, and dysregulated gene expression in liver, muscle, pancreas, and fat tissues (p < 0.05). The addition of MVM reduces these HFD-induced effects. HFD downregulates 27 genes associated with insulin regulation and adipose tissue function across all tissues by an average of 47% and upregulates five genes by 230% (p < 0.001). Adding MVM downregulates five genes and upregulates one in HFD-fed mice. Both HFD and MVM alter one-carbon metabolites.

CONCLUSION

Addition of micronutrients to the HFD decreases IR and modifies associated gene expression in obese and lean mice.

Methylenetetrahydrofolate reductase deficiency and high-dose FA supplementation disrupt embryonic development of energy balance and metabolic homeostasis in zebrafish

Folic acid (synthetic folate, FA) is consumed in excess in North America and may interact with common pathogenic variants in methylenetetrahydrofolate reductase (MTHFR); the most prevalent inborn error of folate metabolism with wide-ranging obesity-related comorbidities. While preclinical murine models have been valuable to inform on diet-gene interactions, a recent Folate Expert panel has encouraged validation of new animal models. In this study, we characterized a novel zebrafish model of mthfr deficiency and evaluated the effects of genetic loss of mthfr function and FA supplementation during embryonic development on energy homeostasis and metabolism. mthfr-deficient zebrafish were generated using CRISPR mutagenesis and supplemented with no FA (control, 0FA) or 100 μm FA (100FA) throughout embryonic development (0-5 days postfertilization). We show that the genetic loss of mthfr function in zebrafish recapitulates key biochemical hallmarks reported in MTHFR deficiency in humans and leads to greater lipid accumulation and aberrant cholesterol metabolism as reported in the Mthfr murine model. In mthfr-deficient zebrafish, energy homeostasis was also impaired as indicated by altered food intake, reduced metabolic rate and lower expression of central energy-regulatory genes. Microglia abundance, involved in healthy neuronal development, was also reduced. FA supplementation to control zebrafish mimicked many of the adverse effects of mthfr deficiency, some of which were also exacerbated in mthfr-deficient zebrafish. Together, these findings support the translatability of the mthfr-deficient zebrafish as a preclinical model in folate research.

Dietary Micronutrients Reduce Insulin Resistance via Adipose Tissue Modulation in Mice Fed a High Fat Diet

Objectives

Obesity is associated with increased insulin resistance (IR) and white adipose tissue (WAT) dysregulation (e.g., decrease in PPAR-γ mRNA expression and impaired leptin sensitivity). Dietary vitamins A, B1, B6, and B12, selenium (Se) and zinc (Zn) have been shown to reduce IR in obesity in animals and humans, but mechanisms have not been defined. The objective of this study is to investigate the effects of selected micronutrients on adipose tissue metabolism and IR in a mouse model of diet-induced obesity (DIO). We hypothesize that these additions modulate genes regulating IR in WAT and improve leptin sensitivity.

Methods

28 DIO male mice were randomly assigned to two high fat (HF, 60 kcal % fat) diets with or without the inclusion of a mineral-vitamin mixture (MVM: 5 × vitamin A, B1, B6, B12, zinc, and 2 × selenium), respectively. Similarly, 28 lean mice were randomized into a low-fat diet (LF, 10 kcal % fat) with or without the MVM. Mice were fed diets ad libitum for 8 weeks. Bodyweight (BW), IR, serum glucose, fasting insulin, C-peptide, leptin, as well as mRNA expression of genes involved in insulin signaling and adipokine secretion were measured in epididymal white adipose tissue (eWAT).

Results

Compared to HF mice, HF-MVM mice exhibited reduced body weight gain over time (by 6%, P &lt; 0.05), improved insulin sensitivity (P &lt; 0.05), reduced fasting glucose (by 18%), insulin (by 45%), C-peptide concentrations (by 26%) and Homeostatic Model Assessment for Insulin Resistance (by 47%, HOMA-IR, P &lt; 0.05 for all). Similarly, LF-MVM had reduced fasting glucose level (P &lt; 0.05) compared to LF mice. As expected, serum leptin concentration (adjusted for a visceral fat mass) was 6-fold higher in HF mice compared to LF mice; HF-MVM mice had lower leptin level compared to the HF mice suggesting improved leptin sensitivity. Ppar-γ gene expression in eWAT was 77% lower in HF vs LF group, suggesting eWAT dysfunction and systemic IR in DIO mice; the addition of MVM to LF diet attenuated this effect.

Conclusions

This MVM mixture may reduce IR through the upregulation of the PPAR-γ system in WAT and improve leptin sensitivity in DIO. Understanding the mechanism of action of micronutrients in reducing IR in a highly relevant animal model will provide new avenues for identifying food component solutions to modify IR in humans.

Funding Sources

Support provided by Various Sponsors (unrestricted funds).

Age and Sex Interact to Determine the Effects of Commonly Consumed Dairy Products on Postmeal Glycemia, Satiety, and Later Meal Food Intake in Adults

BACKGROUND

Dairy consumption reduces postprandial glycemia and appetite when consumed with carbohydrates.

OBJECTIVES

The objective was to test the effects of frequently consumed dairy products, age, and sex on glycemia, appetite, and food intake.

METHODS

In a randomized, unblinded, crossover design, 30 older [60-70 y; BMI (kg/m2): 18.5-29.9] and 28 young (20-30 y; BMI: 18.5-24.9) adults consumed 500 mL of a calorie-free control (water), skim milk and whole milk, 350 g Greek yogurt, and 60 g cheddar cheese. Food intake at an ad libitum meal was measured 120 min later. Glycemia, appetite, and gastric hormone responses were measured premeal (15-120 min), within-meal (120-140 min), and postmeal (140-170 min). Effects of treatment, age, and sex and their interactions were analyzed using ANOVA followed by Tukey's post hoc test.

RESULTS

All forms of dairy, compared with water, decreased postmeal glycemia, premeal appetite, and meal intake (P < 0.0001). Premeal glucose, insulin, and glucagon-like peptide 1 increased, and ghrelin decreased, but effects of dairy differed with age and sex. Older adults had 10% higher pre- and postmeal glucose (P < 0.01). Premeal appetite suppression per 100 kcal of treatments was more after yogurt than other dairy, but overall appetite suppression was less in older adults than in young adults and in males than in females (P < 0.05). Pizza intake was reduced by 175 kcal after yogurt and cheese and by 82 kcal after milks compared to water (P < 0.001). Mealtime reduction for treatment calories averaged 62% after yogurt and cheese but was less at 33% after milks (P < 0.05). Compensation was less in older (33%) than in young (63%) adults (P < 0.03).

CONCLUSIONS

Dairy products consumed in usual forms before a meal stimulate metabolic responses leading to reduced premeal appetite, later food intake, and postmeal glycemia, but their effects differ in magnitude and with the sex and age of adults.

Development of a Zebrafish Model for Studies of the Interaction of Methylenetetrahydrofolate Reductase Deficiency and Dietary Folates on Metabolic Regulation

Objectives

Methylenetetrahydrofolate reductase (MTHFR) is required for 5-methyltetrahydrofolate (5MTHF) synthesis, and common variants reduces its efficiency and associate with metabolic disorders. High folic acid (FA) intakes, commonly consumed by pregnant women in North America, may further inhibit MTHFR enzyme; programming long-term metabolic dysregulation in offspring. The zebrafish (Danio rerio) is a valuable model for study of embryonic development and high-throughput nutrient × gene interactions. The objective of this study was to characterize a zebrafish model of mthfr deficiency and assess the interaction between mthfr and FA intakes on early-life metabolic dysregulation.

Methods

Zebrafish were co-injected with a set of 4 guide RNAs (gRNAs) or cas9 protein alone and F0 embryos were assayed for a high-throughput phenotypic screen. Germline F1 knock-out homozygous mutants (mthfr −/−) were made by co-injecting cas9 mRNA with 2 gRNAs targeting the transcriptional start site of the mthfr gene. Embryos were raised up to 5 days post-fertilization (dpf) and folate and 1-carbon metabolites measured by LC-MS/MS. Lipid accumulation was assessed at 5dpf and after feeding a high cholesterol diet (HDC) with cholesteryl-ester (CE)-BoDipy-C12® from 5–15dpf. A subset of embryos were exposed to no (0µM) or high (100µM) FA from 0–5dpf and whole-body lipids measured.

Results

mthfr disruption in zebrafish reduced (80%) mthfr mRNA and 5MTHF levels (90%) compared to controls (P &lt; 0.0001). They had lower 1-carbon metabolites including betaine, methionine, s-adenosylmethionine, and higher choline, s-adenosylhomocysteine, cystathionine and homocysteine (P &lt; 0.01). As well, neutral lipid accumulation was higher in liver, heart and vasculature at 5 and 15 dpf along with higher CE altered cholesterol transport/metabolism. High FA exposure ameliorated lipid accumulation in mthfr mutants at 5 dpf (P = 0.06), but increased lipids accumulation in controls compared to no exposure (P = 0.03).

Conclusions

The zebrafish mthfr deficient model exhibits a similar alteration to 1-carbon metabolites as in humans with severe MTHFR deficiency. This zebrafish model has potential for understanding the interaction of mthfr deficiency and dietary folates on metabolism.

Funding Sources

CIHR-INMD, EP by NSERC-CGS

High Choline During Pregnancy Reduces Characteristics of the Metabolic Syndrome in Male Wistar Rat Offspring Fed a High Fat Post-Weaning Diet

Objectives

The prenatal period is a critical time for fetal development, programming the offspring's later-life health in response to the postnatal environment. We have shown that a high maternal choline diet programs long-term energy regulation leading to higher food intake and weight-gain in mature rat offspring fed a normal fat diet. However, the offspring's response to an obesogenic post-weaning diet has not been described. We aim to elucidate the interaction between the choline content of the gestational diet (GD) and fat content of the post-weaning diet (PWD) on male Wistar rat offspring's long-term metabolic phenotype.

Methods

Pregnant Wistar rats were fed an AIN-93G diet with either recommended choline (RC, 1g/kg diet choline bitartrate) or high choline (HC, 2.5-fold). Male pups were weaned to either a normal (10%) fat (RC-NF and HC-NF) or a high (45%) fat (RC-HF and HC-HF) diet for 17 weeks. Dependent measures were body weight, food intake, visceral adiposity, plasma glucoregulatory hormones and triglycerides, and plasma and hepatic free fatty acids (FFAs). Data were analyzed with 2-way ANOVA for main effects of GD and PWD and their interaction. Measures with significant interaction effects were followed by a Student's T-test comparing groups stratified by PWD.

Results

HC-HF offspring had lower body weight (7%, P &lt; 0.05), and visceral adiposity (15%, P &lt; 0.05), but no difference in food intake compared to RC-HF. HC-HF offspring had lower insulin (18%, P &lt; 0.05), HOMA-IR (24%, P &lt; 0.01), and plasma triglycerides (30%, P &lt; 0.05) but no difference in leptin. Total hepatic ω-3 FFAs (30%, P &lt; 0.05) were higher and ω-6/ω-3 (P &lt; 0.01) was lower in HC-HF compared to RC-HF, indicating an ameliorated metabolic phenotype in HC-HF offspring. In contrast, HC-NF offspring had higher food intake (8%, P &lt; 0.01) and body weight (6%, P &lt; 0.05) and no difference in adiposity compared to RC-NF. They also had higher plasma leptin adjusted for adiposity (22%, P &lt; 0.05) but not insulin or HOMA-IR compared to RC-NF. Hepatic C16:1n-7/C16:0 ratio was higher in HC-NF compared to RC-NF, suggestive of dysregulated lipid metabolism.

Conclusions

Gestational choline supplementation is associated with improved long-term metabolic regulation in male Wistar rat offspring fed a high fat post-weaning diet.

Funding Sources

CIHR-Institute of Nutrition, Metabolism, and Diabetes.

Methylenetetrahydrofolate Reductase Deficiency Reduces Brain Microglia in Zebrafish During Embryonic Development and Is Not Corrected by Folic Acid

Objectives

Neuronal development and function is dependent on the interaction between the central nervous system and immune system. Microglia are resident macrophages of the brain critical for regulating neuronal activity during embryonic development. 5-methyltetrahydrofolate (5MTHF), the bioactive folate form, is essential for fetal brain development and immune function. Common variants in methylenetetrahydrofolate reductase (MTHFR), required for conversion of folic acid (FA) to 5-MTHF, limits its production. High dose FA supplementation is recommended but high FA may have the converse effect of reducing MTHFR activity. The objective of this study was to determine the effects of mthfr deficiency and its interaction with FA during embryonic development on microglia in a zebrafish model.

Methods

The mthfr gene in zebrafish was disrupted using two CRISPR mutagenesis methods. A set of 4 guide RNAs (gRNAs) + cas9 protein or cas9 alone (control) were injected to assay F0 zebrafish, or 2 gRNAs + cas9 mRNA were used to induce a germline mutation. To visualize macrophages at 4 days post fertilization (dpf) in live zebrafish, the transgenic mpeg1: mcherry line was used. In a subset of embryos, FA was added at 0, 50, 75, or 100- μM from 0–4dpf. At 4dpf, live neutral red staining for microglia was performed and the number in the optic tectum was quantified. 5MTHF, s-adenosylmethionine (SAM) and s-adenosylhomocysteine (SAH) were assayed in whole zebrafish at 5dpf.

Results

In vivo imaging revealed a reduction in macrophage number (∼30%, P &lt; 0.001) in the head region of mthfr disrupted zebrafish, but not in the periphery. mthfr zebrafish also had less microglia compared to controls (15%, P &lt; 0.001). These changes were associated with lower 5MTHF (90%, P &lt; 0.0001) and SAM: SAH (∼50%, P &lt; 0.001) at 5dpf indicative of lower methylation potential. Exposure with FA did not correct the phenotype and at 100µM FA, control zebrafish also showed a decrease in microglia similar to mthfr zebrafish, confirming inhibitory effects of the high FA dose.

Conclusions

mthfr deficiency reduces microglia in zebrafish but supplementation with FA does not prevent and may exacerbate the negative effects. The 5MTHF form of folate may be a better alternative to FA for brain health in patients with underlying genetic conditions.

Funding Sources

Supported by CIHR-INMD.

High 5-Methyletetrahydrofolate and Folic Acid Gestational Diets Differ on Leptin-Dependent Hypothalamic Genes Regulating Food Intake in Female Offspring

Objectives

While the replacement of folic acid (FA) with the bioactive folate form 5-methyltetrahydrofolate (MTHF) is gaining popularity, a comparison of their effects during pregnancy is limited. In a comparison of maternal intakes of FA and MTHF at recommended or high (5X) doses in Wistar rat dams, we found that dams fed 5X MTHF gained &gt; 70% more weight and ate 8% more food to 19-weeks post weaning (PW) than those fed the high FA diet (Nutrients. 2021;13:48). However, both high dose diets resulted in dysregulation of leptin and central energy regulatory systems. The objective of this study was to compare the effect of gestational FA and MTHF diets on metabolic response and leptin-dependent hypothalamic energy-regulatory genes in the brain of their female offspring.

Methods

Pregnant Wistar rats were fed an AIN-93G diet with 1X recommended (2mg/kg diet) or 5X FA or equimolar MTHF. At weaning, female offspring were fed a high-fat diet until 19-weeks PW. Body weight, food intake, adiposity, plasma leptin, and gene expression of leptin signaling and related candidate genes in the hypothalamus were measured.

Results

Similar to the mothers, the 5X-MTHF gestational diet resulted in offspring with higher weight (&gt;15%, P &lt; 0.01) independent of visceral adiposity, and higher food intake (8% P &lt; 0.01) compared to those born to dams fed the 5X-FA, but not from the 1X folate diets. Both 5X diets led to higher plasma leptin at birth (60%, P &lt; 0.05) and at 19-weeks PW (40%, P &lt; 0.01) and up-regulated hypothalamic mRNA of the downstream leptin signalling gene, signal transducer and activator of transcription-3 (Stat3). However, only 5X-MTHF offspring had lower expression of leptin receptor (Ob-rB) and higher expression of suppressor of cytokine signaling-3 (Socs-3), an inhibitor of leptin signalling and indicator of central leptin resistance. In contrast, 5X-FA offspring had higher expression (&gt;1.5-fold, P &lt; 0.01) of dopamine and GABA- receptors which are targets of leptin and associated with feeding inhibition and hyperactivity.

Conclusions

Folate form and dose during pregnancy affects long-term programming of leptin dependent hypothalamic regulatory pathways in female offspring. Unfavorable differences in response to FA and MTHF were seen at the higher doses, thus neither should be consumed at high intakes.

Funding Sources

CIHR-INMD; EP by NSERC-CGS.

High Intakes of [6S]-5-Methyltetrahydrofolic Acid Compared with Folic Acid during Pregnancy Programs Central and Peripheral Mechanisms Favouring Increased Food Intake and Body Weight of Mature Female Offspring

Supplementation with [6S]-5-methyltetrahydrofolic acid (MTHF) is recommended as an alternative to folic acid (FA) in prenatal supplements. This study compared equimolar gestational FA and MTHF diets on energy regulation of female offspring. Wistar rats were fed an AIN-93G diet with recommended (2 mg/kg diet) or 5-fold (5X) intakes of MTHF or FA. At weaning, female offspring were fed a 45% fat diet until 19 weeks. The 5X-MTHF offspring had higher body weight (>15%), food intake (8%), light-cycle energy expenditure, and lower activity compared to 5X-FA offspring (p < 0.05). Both the 5X offspring had higher plasma levels of the anorectic hormone leptin at birth (60%) and at 19 weeks (40%), and lower liver weight and total liver lipids compared to the 1X offspring (p < 0.05). Hypothalamic mRNA expression of leptin receptor (ObRb) was lower, and of suppressor of cytokine signaling-3 (Socs3) was higher in the 5X-MTHF offspring (p < 0.05), suggesting central leptin dysregulation. In contrast, the 5X-FA offspring had higher expression of genes encoding for dopamine and GABA- neurotransmitter receptors (p < 0.01), consistent with their phenotype and reduced food intake. When fed folate diets at the requirement level, no differences were found due to form in the offspring. We conclude that MTHF compared to FA consumed at high levels in the gestational diets program central and peripheral mechanisms to favour increased weight gain in the offspring. These pre-clinical findings caution against high gestational intakes of folates of either form and encourage clinical trials examining their long-term health effects when consumed during pregnancy.

High Choline Intake during Pregnancy Reduces Characteristics of the Metabolic Syndrome in Male Wistar Rat Offspring Fed a High Fat But Not a Normal Fat Post-Weaning Diet

Maternal choline intakes are below recommendations, potentially impairing the child’s later-life metabolic health. This study aims to elucidate the interaction between the choline content of the gestational diet (GD) and fat content of the post-weaning diet (PWD) on metabolic phenotype of male Wistar rats. Pregnant Wistar rats were fed a standard rodent diet (AIN-93G) with either recommended choline (RC, 1 g/kg diet choline bitartrate) or high choline (HC, 2.5-fold). Male pups were weaned to either a normal (16%) fat (NF) or a high (45%) fat (HF) diet for 17 weeks. Body weight, visceral adiposity, food intake, energy expenditure, plasma hormones, triglycerides, and hepatic fatty acids were measured. HC-HF offspring had 7% lower body weight but not food intake, and lower adiposity, plasma triglycerides, and insulin resistance compared to RC-HF. They also had increased hepatic n-3 fatty acids and a reduced n-6/n-3 and C 18:1 n-9/C18:0 ratios. In contrast, HC-NF offspring had 6–8% higher cumulative food intake and body weight, as well as increased leptin and elevated hepatic C16:1 n-7/C16:0 ratio compared to RC-NF. Therefore, gestational choline supplementation associated with improved long-term regulation of several biomarkers of the metabolic syndrome in male Wistar rat offspring fed a HF, but not a NF, PWD.

The effect of dairy products and non-dairy snacks on food intake, subjective appetite and cortisol levels in children: a randomized control study

Dairy snacks are available in various physical forms and their consumption is linked to improved metabolic health. The objective of this study was to determine the effect of dairy snacks of different physical forms on short-term food intake (FI), subjective appetite, and the stress hormone, cortisol, in children. Following a repeated-measures crossover design, 40 children aged 9-14 years randomly consumed 1 of 5 isoenergetic (180 kcal) snacks per study session. These snacks included solid (potato chips, cookies, and cheese), semi-solid (Greek yogurt), and fluid (2% fat milk) snacks. FI was measured 120 min after snack consumption. Subjective appetite was measured at 0 (immediately before the snack), 15, 30, 45, 60, 90, and 120 min. Salivary cortisol (n = 18) was measured after the Greek yogurt and cookie snacks at 0, 30, 60, 90, and 120 min. FI did not differ between snacks (P = 0.15). The Greek yogurt (P < 0.0001) and cheese (P = 0.0009) snacks reduced average appetite compared with the 2% fat milk snack. Salivary cortisol levels were not affected by snack (P = 0.84). This study demonstrates that dairy snacks are as effective as other popular snacks at influencing subsequent FI. However, solid and semi-solid dairy snacks are more effective at repressing subjective appetite than a fluid dairy snack. Registered at ClinicalTrials.gov (NCT02484625). Novelty: Milk, Greek yogurt and cheese have a similar effect on short-term food intake in children as popular potato chips and cookie snacks. Solid, semi-solid and liquid snacks have a similar effect on short-term food intake in children.

An examination of contributions of animal- and plant-based dietary patterns on the nutrient quality of diets of adult Canadians

Dietary guidance and Canada's 2019 Food Guide encourage increased consumption of plant-based foods as a source of dietary protein. However, there is an absence of recent data on protein and nutrient intakes and quality of Canadian dietary patterns that might occur with increased plant protein intakes. This study compared food sources and nutrient intakes of Canadian adults within groups of increasing plant protein-containing diets. The CCHS 2015 Public-Use Microdata File of single 24-hour dietary recalls of males and females ≥19 years (n = 6498) or ≥70 years (n = 1482) were examined. Respondents were allocated into 4 groups defined by their protein intake percentage coming from plant-based foods (i.e., group 1: 0-24.9%, group 2: 25-49.9%, group 3: 50-74.9%, group 4: 75-100%). Protein intake in adults averaged 63.3% animal and 36.7% plant protein. Where plant protein contributed >50% protein, higher intakes of carbohydrate, dietary fibre, folate, dietary folate equivalents, iron and magnesium (p < 0.001) but lower intakes of total and saturated fat, protein, vitamin D, vitamin B12, riboflavin and niacin (p < 0.0001) were reported. In contrast, group 1 had higher total and saturated fat, protein, vitamin B12, thiamin, niacin, and zinc, but lower carbohydrate, dietary fibre, and magnesium. Balancing plant- with animal-based protein foods leads to healthier dietary patterns with more favourable nutritional properties when compared with diets based on either high animal or high plant protein content. Novelty: Combinations of animal- and plant-based proteins improve nutrient quality of Canadian diets. The source of protein influences diet quality.

Choline and Folic Acid in Diets Consumed during Pregnancy Interact to Program Food Intake and Metabolic Regulation of Male Wistar Rat Offspring

BACKGROUND

North American women consume high folic acid (FA), but most are not meeting the adequate intakes for choline. High-FA gestational diets induce an obesogenic phenotype in rat offspring. It is unclear if imbalances between FA and other methyl-nutrients (i.e., choline) account for these effects.

OBJECTIVE

This study investigated the interaction of choline and FA in gestational diets on food intake, body weight, one-carbon metabolism, and hypothalamic gene expression in male Wistar rat offspring.

METHODS

Pregnant Wistar rats were fed an AIN-93G diet with recommended choline and FA [RCRF; 1-fold, control] or high (5-fold) FA with choline at 0.5-fold [low choline and high folic acid (LCHF)], 1-fold [recommended choline and high folic acid (RCHF)], or 2.5-fold [high choline and high folic acid (HCHF)]. Male offspring were weaned to an RCRF diet for 20 wk. Food intake, weight gain, plasma energy-regulatory hormones, brain and plasma one-carbon metabolites, and RNA sequencing (RNA-seq) in pup hypothalamuses were assessed.

RESULTS

Adult offspring from LCHF and RCHF, but not HCHF, gestational diets had 10% higher food intake and weight gain than controls (P < 0.01). HCHF newborn pups had lower plasma insulin and leptin compared with LCHF and RCHF pups (P < 0.05), respectively. Pup brain choline (P < 0.05) and betaine (P < 0.01) were 22-33% higher in HCHF pups compared with LCHF pups; methionine was ∼23% lower after all high FA diets compared with RCRF (P < 0.01). LCHF adult offspring had lower brain choline (P < 0.05) than all groups and lower plasma 5-methyltetrahydrofolate (P < 0.05) than RCRF and RCHF groups. HCHF adult offspring had lower plasma cystathionine (P < 0.05) than LCHF adult offspring and lower homocysteine (P < 0.01) than RCHF and RCRF adult offspring. RNA-seq identified 144 differentially expressed genes in the hypothalamus of HCHF newborns compared with controls.

CONCLUSIONS

Increased choline in gestational diets modified the programming effects of high FA on long-term food intake regulation, plasma energy-regulatory hormones, one-carbon metabolism, and hypothalamic gene expression in male Wistar rat offspring, emphasizing a need for more attention to the choline and FA balance in maternal diets.

Faba bean meal, starch or protein fortification of durum wheat pasta differentially influence noodle composition, starch structure and in vitro digestibility

Faba bean (Vicia faba L.) flour, starch concentrate (60% starch), protein concentrate (~60% protein) and protein isolate (~85% protein) were added to replace one-quarter of durum wheat semolina to enrich the nutritional quality and physiological functions of durum wheat (Triticum turgidum L.) pasta. The raw pasta samples prepared with protein concentrate or isolate had higher (p ≤ 0.001) protein and lower (p ≤ 0.001) total starch concentrations, along with increased total dietary fiber and slowly digestible starch (p ≤ 0.001) than durum wheat semolina control or those with added whole faba-bean flour or isolated starch. The faba bean fortified pasta had altered starch with increased proportion of medium B-type glucan chains and long C-type glucan chains, reduced starch digestibility and were associated with glycaemia related effects in the human diet. The faba bean fortified pasta had increased protein and dietary fiber that influenced food intake and satiety. The results suggest differential contributions of food ingredients in human health outcomes.

Role of Amino Acids in Blood Glucose Changes in Young Adults Consuming Cereal with Milks Varying in Casein and Whey Concentrations and Their Ratio

BACKGROUND

Increasing the total protein content and reducing the casein to whey ratio in milks consumed with breakfast cereal reduce postprandial blood glucose (BG).

OBJECTIVES

We aimed to explore associations between plasma amino acids (AAs), BG, and glucoregulatory hormones.

METHODS

In this repeated-measures design, 12 healthy adults consumed cereal (58 g) and milks (250 mL) with 3.1 wt% or high 9.3 wt% protein concentrations and with casein to whey ratios of either 80:20 or 40:60. Blood was collected at 0, 30, 60, 120, 140, 170, and 200 min for measurement of the primary outcome, BG, and for the exploratory outcomes such as plasma AA, gastric emptying, insulin (INS), and glucoregulatory hormones. Measures were made prior to and after an ad libitum lunch at 120 min. Exploratory correlations were conducted to determine associations between outcomes.

RESULTS

Pre-lunch plasma AA groups [total (TAA), essential (EAA), BCAA, and nonessential (NEAA)] were higher after 9.3 wt% than 3.1 wt% milks by 12.7%, 21.4%, 20.9%, and 7.6%, respectively (P ≤ 0.05), while post-lunch AA groups were higher by 10.9%, 19.8%, 18.8%, and 6.0%, respectively (P ≤ 0.05). Except for NEAA, pre-lunch AAs were higher after 40:60 than 80:20 ratio milks by 4.5%, 8.3%, and 9.3% (P ≤ 0.05). When pooled by all treatments, pre-lunch AA groups associated negatively with BG (r/ρ ≥ -0.45, P ≤ 0.05), but post-lunch only TAA and NEAA correlated (r ≥ -0.37, P < 0.05). Pre-lunch BG was inversely associated with Leu, Ile, Lys, Met, Thr, Cys-Cys, Asn, and Gln (r/ρ ≥ -0.46, P ≤ 0.05), but post-lunch, only with Thr, Ala, and Gly (r ≥ -0.50, P ≤ 0.05). Pre-lunch associations between AA groups and INS were not found.

CONCLUSIONS

Protein concentration and the ratio of casein to whey in milks consumed at breakfast with cereal affect plasma AA concentrations and their associations with decreased BG. The decrease in BG could be explained by INS-independent mechanisms. This trial was registered at www.clinicaltrials.gov as NCT02471092.

High 5MTHF, but Not Folic Acid During Pregnancy, Alters Hypothalamic Regulatory Pathways and Associates with Post-Partum Weight-Gain in Wistar Rat Mothers

Objectives

5-methyltetrahydrofolate (5MTHF), the bioactive folate form, has been proposed an alternative supplement to folic acid (FA) due to direct cellular uptake and utilization. In North America, 5MTHF is incorporated into prenatal supplements at the equivalent high dose (1000 µg) as FA and discussion has been raised of its formation into baby formula. Our lab was the first to compare the dose (1X vs high, 5X) and form (FA vs 5MTHF) effects of folate during pregnancy on later-life metabolic health of the Wistar rat mother. Contrary to our hypothesis, 5MTHF diets, independent of dose, led to mothers with 40% greater body weight-gain and higher food intake post-birth compared to FA. The objective of this study was to identify differentially expressed genes and related hypothalamic pathways of mothers fed FA vs 5MTHF diets during pregnancy.

Methods

Pregnant Wistar rats were fed an AIN-93 G diet with recommended (1X, control, 2 mg/kg diet) or high (5X) FA or equimolar levels of 5MTHF. At birth, a subset of dams were terminated and RNA-seq analysis was performed in the arcuate nucleus of the hypothalamus (ARC), a key regulator of body weight and food intake, in dams fed the high FA and MTHF diets.

Results

Over 350 differentially expressed genes were identified in the ARC of dams fed high 5MTHF vs FA diets. Combining differential gene expression patterns with reported GO function terms and Kegg pathway analyses, four candidate genes (prolactin hormone receptor, corticotropin releasing hormone receptor, KISS1 peptide and dopamine receptor) were validated by qPCR thus far as plausible contributors to higher body weight-gain and food intake in 5MTHF dams. These genes correspond to neuroactive ligand-receptor interaction pathway (path: hsa04080), associated with metabolic diseases including leptin deficiency and genetic obesity. Other significantly enriched pathways included the retrograde endocannabinoid signalling and morphine addiction pathway.

Conclusions

High 5MTHF supplementation during pregnancy alters expression of central feeding regulatory pathways in the hypothalamus of the mother, potentially programming post-partum body-weight gain. 5MTHF, at the equivalent dose of FA, may not be the preferred folate form during pregnancy.

Funding Sources

CIHR-INMD; EP supported by NSERC-CGS D.

Choline Supplementation Mitigates the Adverse Effects of a High Folic Acid Maternal Diet on Food Intake Regulation in the Offspring

Objectives

Folic acid (FA) intake by many women in North America is exceeding recommendations. We have shown that high maternal FA induces methylation-dependent programming of energy regulation associated with an obesogenic phenotype in adult rat offspring. However, it is unclear if this is a direct effect of high FA or due to an imbalance between FA and other methyl-nutrients (i.e., choline) in the 1-carbon cycle. Unlike FA, choline intake by women is below recommendations and is absent from most prenatal supplements, potentially affecting fetal development. The objective of this study was to examine the mechanisms and effects of choline content in high FA maternal diets on in-utero programming of energy regulation and later-life offspring phenotype.

Methods

Pregnant Wistar rats were fed an AIN-93 G diet with recommended FA and choline (1X, RFRC, control), or 5X-FA diet with choline at 0.5X-(HFLC), 1X-(HFRC), or 2.5X- (HFHC). In pups at birth, brain and liver 1-carbon metabolites, hypothalamic DNA methyltransferase (DNMT) activity and global DNA methylation (5-mC%) were measured. At weaning, one male pup/dam was fed the control diet and weekly weight-gain and food intake were recorded for 20 weeks.

Results

Offspring born to dams on the HFLC and HFRC, but not HFHC diet, had higher food intake (P &lt; 0.05) and weight-gain (P &lt; 0.01) than controls. In liver at birth, free choline was lower in HFHC than in HFLC pups, but betaine was unaffected. In contrast, in brains, betaine but not free choline concentrations, directly reflected the maternal choline diets. These results suggest that choline may modulate central food intake pathways via the methyl-donor betaine, warranting further investigation. Hypothalamic DNMT activity was highest (P &lt; 0.05) in HFLC pups but global methylation was not affected. Thus, gene expression by RNA sequencing and gene-specific methylation in the hypothalamus is in progress to elucidate the mechanisms underlying the observed phenotype.

Conclusions

Increased maternal choline mitigates the high FA diet induced increase in body weight and food intake in the adult offspring and results in tissue-specific changes in 1-carbon metabolism at birth. These findings have potential application to human health, providing support to optimize choline and FA intakes by women of childbearing age.

Funding Sources

CIHR-INMD.

The Zebrafish (Danio Rerio) as a Novel Model to Study Folate-mthfr Interactions During Embryonic Development and Effect(s) on Long-Term Health

Objectives

Methylenetetrahydrofolate reductase (MTHFR) catalyzes the synthesis of the bioactive folate form, 5-methyltetrahydrofolate (5MTHF). Common polymorphisms in MTHFR limits the availability of 5MTHF and high intakes of folic acid (FA, synthetic form) may exacerbate these effects. 5MTHF is an alternative supplement to FA, but the interaction of folate form and MTHFR genotype and role in programming metabolic health has not been determined. The zebrafish (Danio rerio) is a proven model system in nutrient and drug discovery studies. The objectives of this study were to: 1) develop a mthfr zebrafish mutant model using CRISPR-Cas9 technology; and 2) identify in zebrafish the relationship between folate form (FA vs 5MTHF) and mthfr genotype on early-life development and metabolic regulation.

Methods

To assay the function of mthfr in vivo, we used a rapid transient knock-out approach reported to recapitulate germline zebrafish loss-of-function phenotypes. Embryos were co-injected with Cas9 protein and a set of 4 guide RNAs (4gRNA) or Cas9 protein alone (control). Zero to 5 days post-fertilization (dpf), embryos were raised in standard conditions then fed a high cholesterol diet (HCD) up to 15 dpf with a fluorescent cholesteryl BODIPY-C12. The HCD was used to induce obesity as previously reported. Global DNA methylation (5-mC%) was measured at 5 dpf and whole-body and hepatic lipid accumulation and live imaging analyses performed at 15 dpf.

Results

Compared to control, 4gRNA mthfr zebrafish on an HCD had enlarged liver, greater accumulation of hepatic and whole body lipids and altered lipid transport. They also had 80% lower mthfr mRNA than control zebrafish. Global methylation was ∼15% higher (P = 0.06) in 4gRNA zebrafish suggesting a compensatory dependency on an alternative methyl donor pathway during embryonic development. We are now screening germline mutant carriers and assessing folate and methylation metabolites and the interaction of folate form and genotype.

Conclusions

The zebrafish mthfr mutant will be a valuable model to examine the mechanisms underlining mthfr-related pathologies and provide a high-throughput in vivo system to ascertain the role of different folate forms on embryonic development and long-term health.

Funding Sources

CIHR-INMD; EP supported by NSERC-CGS D.

Ethanolamides of essential α-linolenic and linoleic fatty acids suppress short-term food intake in rats

Food source has a significant impact on levels of fatty acids and their derivatives, fatty acid ethanolamides (FAEs), in the small intestine and brain. Among non-essential fatty acids, oleic acid and its FAE acutely reduce food intake. However, effects of the essential α-linolenic acid, linoleic acid, and their FAEs on appetite regulation remain undefined. This study tested the hypothesis that α-linolenic acid and linoleic acid mediate acute suppression of food intake through their corresponding FAEs, α-linolenoylethanolamide and linoleoylethanolamide, respectively. To allow for the differentiation of the effects of FAEs and their parent fatty acids, male Wistar rats were injected intraperitoneally with α-linolenic acid, linoleic acid, α-linolenoylethanolamide and linoleoylethanolamide after a 12-hour overnight fast. Short-term food intake, plasma and brain FAE status, and plasma concentrations of insulin and leptin were measured to determine whether these hormones mediate the anorectic effect of FAEs. Both ethanolamides, but not their parent fatty acids, acutely suppressed food intake up to one hour post-treatment and this effect was independent of insulin and leptin hormones. In conclusion, essential α-linolenic and linoleic fatty acids mediate acute suppression of food intake through their corresponding FAEs. These findings may aid in the further research of FAEs as potential therapeutic agents for the management and treatment of obesity.

Effects of cultured dairy and nondairy products added to breakfast cereals on blood glucose control, satiation, satiety, and short-term food intake in young women

Breakfast cereals are often consumed with dairy products or nondairy alternatives; however, the effect of the combination on blood glucose and food intake control is not well investigated. In a randomized, crossover study, 24 healthy women (age: 22.7 ± 2.5 years; body mass index: 22.1 ± 1.5 kg/m²) consumed, to satiation, 1 of 3 treatments: Greek yogurt with granola (150 kcal, 9.2 g protein, 2.6 g fat, 2.0 g dietary fibre, and 21.5 g available carbohydrate/100 g); cultured coconut product with granola (146 kcal, 3.2 g protein, 3.2 g fat, 5.6 g dietary fibre, and 21.9 g available carbohydrate/100 g); or water control. The data were analyzed with repeated-measures ANOVA. The 2 h blood glucose iAUC was 52% lower after the dairy compared with nondairy treatment (P < 0.0001). While there were no differences in food intake between the caloric treatments consumed to satiation, protein intake was 3 times higher and fibre intake was 4 times lower after the dairy compared with nondairy treatment. Both caloric treatments resulted in similar suppression of ad libitum food intake at 2 h (P < 0.003) and subjective appetite over 2 h (P < 0.0001) compared with water. The cumulative food intake over 2 h was lower after water (P < 0.05). The 1.8-fold increase in postprandial insulin after dairy compared with nondairy treatment may explain the reduction in blood glucose without an increase in subsequent energy intake. Novelty Blood glucose in young females is lower after a breakfast with granola in a high-protein cultured dairy than when in a high-fibre nondairy cultured product. Subjective appetite over 2 h and food intake 2 h later was similarly lower after both breakfasts but cumulative intake was higher compared with breakfast skipping.

Maternal Choline Intake Programs Hypothalamic Energy Regulation and Later-Life Phenotype of Male Wistar Rat Offspring

SCOPE

High-folic-acid diets during pregnancy result in obesity in the offspring, associated with altered DNA-methylation of hypothalamic food intake neurons. Like folic acid, the methyl-donor choline modulates foetal brain development, but its long-term programing effects on energy regulation remain undefined. This study aims to describe the effect of choline intake during pregnancy on offspring phenotype and hypothalamic energy-regulatory mechanisms.

METHODS AND RESULTS

Wistar rat dams are fed an AIN-93G diet with recommended choline (RC, 1 g kg^-1 diet), low choline (LC, 0.5-fold), or high choline (HC, 2.5-fold) during pregnancy. Male pups are terminated at birth and 17 weeks post-weaning. Brain 1-carbon metabolites, body weight, food intake, energy expenditure, plasma hormones, and protein expression of hypothalamic neuropeptides are measured. HC pups have higher expression of the orexigenic neuropeptide-Y neurons at birth, consistent with higher cumulative food intake and body weight gain post-weaning compared to RC and LC offspring. LC pups have lower leptin receptor expression at birth and lower energy expenditure and activity during adulthood.

CONCLUSION

Choline content of diets that are consumed by rats during pregnancy affects the later-life phenotype of offspring, associated with altered in utero programing of hypothalamic food intake regulation.

An Animal Model for the Study of Amino Acid Metabolism in Uremia and during Peritoneal Dialysis

We tried to determine the suitability of the rabbit as an animal model to study amino acid (AA) metabolism in continuous ambulatory peritoneal dialysis. We also measured the effect of intraperitoneal (ip) infusion of AA on blood AA changes and food consumption.

Plasma AA levels were measured in 10 normal rabbits after an overnight fasting and 30, 60, and 120 minutes after a meal. Following these baseline observations, rabbits were randomly divided into two groups. One group of five rabbits was made uremic after surgical partial nephrectomy, whereas the remaining (controls) underwent sham operations. Two weeks after the induction of uremia we measured the effect of chronic renal failure on fasting and postprandial (30,60,120 minutes) plasma AA levels. Upon the completion of the second experiment (4 weeks after the induction of uremia) we studied the effect of an ip AA on plasma AA profile 1, 2, 4, and 6 hours after the infusion in both uremic and control rabbits. We also measured the food intake in all experiments.

The results of our experiments showed the following: 1. plasma AA in the rabbits decreased after induction of chronic renal failure and increased after food ingestion and ip infusion of AA solution; 2. neither induction of uremia nor ip AA infusion have an effect on food consumption; 3. the majority of the alterations in plasma AA levels we observed in the uremic rabbits were similar to those observed in humans, indicating that the rabbit may be a suitable model for the study of AA metabolism in chronic renal failure and during peritoneal dialysis.

Six-Month Overnight Intraperitoneal Amino-Acid Infusion in Continuous Ambulatory Peritoneal Dialysis (CAPO) Patients-No Effect on Nutritional Status

The long-term effect of an AA solution based on Tra-vasol®, a solution for total parenteral nutrition, given in-traperitoneally over a 6-month period was studied in 5 patients 22 to 75 years old, having been on continuous ambulatory peritoneal dialysis (CAPD) for 3 to 57 months. A low oral protein intake (<0.8 g/kg bw /day) and/or a low serum albumin «35 g/L) were used as inclusion criteria. Two liters of 1% AA solution were infused overnight, while a glucose Dianeal® was used for the other exchanges. During the study, BUN increased from 22.04 mM/L to 28.06 mM/L the first month and remained at these levels, indicating the increased protein intake. However, average oral total energy and protein intake, body weight (bw), serum creatinine, cholesterol, triglycerides, total proteins, albumin, transferrin, skinfold thickness, total body potassium, and plasma AA levels remained basically unchanged. The average total body nitrogen decreased from 1.746 to 1.554 Kg, but this decrease did not reach statistical significance (p > 0.05).

We conclude that intraperitoneal overnight administration of 2 L of 1% AA based on Travasol® over 6 months did not improve the nutritional status of CAPD patients. This ineffectiveness might be due to the AA composition of the solution, the timing of administration, or to a low caloric intake and/or that our patients were not severely malnourished.

Amino Acid Absorption following Intraperitoneal Administration in CAPD Patients

Six non-diabetic CAPD patients were infused over six hours with two litres of a dialysis solution containing 2 g/ dl amino acids (a mixture of essentials and non-essentials). The osmolality of the solution and the amount of ultrafiltration it induced were simiiar to that of a 4.25 g% dextrose Dianeal solution (control), suggesting that an amino acid solution is an efficient osmotic agent. By the end of the six-hour infusion, 80 to 90% of the amino acids present in the dialysis solution had been absorbed. One hour after the infusion was instituted, plasma amino acid levels increased threefold and subsequently decreased to near the initial value by the sixth hour. The amino acid solution was as effective as the dextrose solution in removing urea nitrogen, creatinine and potassium.

Our data indicate that intraperitoneal administration of amino acids is effective and well-tolerated in patients on CAPD. We believe further work should be done to determine whether long-term administration of amino acids by this route will improve the nutritional status of these patients and prevent the side effects of daily absorption of large amounts of glucose.

Effective Use of Amino Acid Dialysate over four Weeks in CAPD Patients

We studied the effectiveness, tolerance to, and beneficial metabolic effects of amino acid dialysate over an intermediate period in six CAPD patients. Two liters of 1% amino acid solution (Amino-Dianeal) were alternated with dialysate containing glucose. After four weeks there were significant increases in BUN (from 64 to 102 mg%), total body nitrogen (from 1333 to 1380 g), serum transferrin (from 175 to 222 mg%) and anion gap (from 15.1 to 17.3). Initially, there was a significant rise in HDL cholesterol, however, this was not sustained. No significant change was detected in total-body potassium, fasting serum albumin, triglyceride, insulin, glucagon, electrolytes, anthropometric measurements and daily ingestion of calories and proteins. During the study individual fasting, plasma amino acid levels showed significant increments in respect to histidine, tryptophan and glycine but alanine decreased. Several essential amino acids continued to show values below normal. Two hours after consumption of breakfast and concurrent infusion of the amino acid solution, the plasma levels of the amino acids in the dialysate peaked at emia, which develops in almost onehalf of the CAPD patients (7), and the significant weight gain observed in some of them. Furthermore, the daily losses of albumin and amino acids in the dialysate may induce protein malnutrition, especially if these losses are not replaced by an adequate daily protein intake. The presence of protein malnutrition in CAPD patients is indicated by the low serum albumin and total protein, and by the decrease in total body nitrogen over one year of CAPD (8).

Assessment of Rat Growth Methods for Estimating Protein Quality: Interlaboratory Study

An interlaboratory study involving protein efficiency ratio (PER), net protein ratio (NPR), relative NPR (RNPR) and relative nitrogen utilization (RNU) was carried out. Six collaborators assayed 6 samples, including casein plus methionine which was used as a reference protein. Collaborators prepared their own diets and analyzed the diets for nitrogen. Test proteins were added at the 8% level (N × 6.25). PER values varied more than NPR values which varied more than either RNPR or RNU. RNU and RNPR produced almost identical values, but RNPR remains the official method of choice, because it is a well established method.

Increased milk protein content and whey-to-casein ratio in milk served with breakfast cereal reduce postprandial glycemia in healthy adults: An examination of mechanisms of action

This study describes the effects on glycemic response and the underlying mechanisms of action of increasing the protein concentration and decreasing the casein-to-whey ratio in milk when consumed with a high glycemic breakfast cereal. Twelve healthy men and women, aged 18 to 30 yr and with a body mass index of 20 to 24.9 kg/m², consumed (in random order) milk beverages (250 mL) containing either 3.1 or 9.3% protein and casein-to-whey ratios of either 80:20 or 40:60. We measured postprandial appetite, glucose, regulatory hormones, and stomach emptying rate over 200 min, as well as food intake at an ad libitum meal at 120 min. Although pre-meal appetite was suppressed to a greater extent with milk beverages that had high (9.3%) compared with regular (3.1%) protein content, food intake was similar among all 4 treatments. Pre-meal mean blood glucose was lower with beverages that had high rather than regular milk protein content, with the lowest glucose peaks after the high milk protein treatment with the 40:60 casein-to-whey ratio. Pre-meal insulin and C-peptide levels were not affected by milk protein content or casein-to-whey ratio, but pre-meal glucagon-like peptide 1 was higher after the treatment containing high milk protein and the 40:60 casein-to-whey ratio, and pre-meal cholecystokinin was higher after the treatments containing high milk protein content. Plasma paracetamol response was also lower after the treatments containing high compared with regular milk protein content. When consumed with carbohydrate, milk beverages with high protein content and (to a lesser extent) a decreased casein-to-whey ratio lowered postprandial glycemia through insulin-independent mechanisms, primarily associated with delayed stomach emptying.

Optimizing foods for special dietary use in Canada: key outcomes and recommendations from a tripartite workshop

Many health conditions result in unique nutritional requirements (e.g., protein restriction, low energy, fortification) and the need to consume foods in nontraditional formats (e.g., liquid diets, supplements, tube feeding). In Canada, 45% of hospital patients are malnourished upon admission, resulting in prolonged hospital stays, increased health care costs, and higher mortality rates. Fortunately, advances in nutrition and food science enabled the development of products that provide nutritional support for individuals in hospital and at home. In Canada, these products are defined as Foods for Special Dietary Use (FSDUs). Canada's regulation of FSDUs (Division 24 of the Food and Drug Regulations) is particularly stringent and outdated, which results in products that do not meet current nutritional recommendations or allow application of current technologies, and lack harmonization with other countries. Many of these issues also apply to the Infant Food regulations in Canada. To provide vulnerable populations with optimal nutrition, experts have suggested modernization of Canadian FSDU regulations. A multi-stakeholder workshop established several recommendations and goals toward that end while ensuring the safety of consumers. These include (i) assessing other jurisdictions' regulations; (ii) tracking products currently on the market; (iii) temporary marketing authorizations to permit products on the market and collect data; (iv) use of incorporation by reference for compositional requirements; (v) support for research of FSDU and nutritional needs of special population; and (vi) better understanding accessibility to these products. Overall, the proposed vision is for a modern, safe, flexible, innovative, and health-driven regulatory framework for FSDU in Canada.

5-Methyltetrahydrofolate in Maternal Diets Alters DNA Methylation Potential and Increases Later Life Weight Gain and Food Intake in Wistar Rat Dams and Female Offspring (P11-022-19)

Objectives

Diet during pregnancy programs the mother and offspring post-weaning (PW). Folic acid (FA, synthetic folate) mediates DNA methylation (DNAm) reactions and high intakes, simulating those consumed by American women, lead to epigenetic dysregulation of energy metabolic pathways. 5-methyltetrahydrofolate (5MTHF), the bioactive folate form, has gained popularity as a supplement due to direct cellular uptake and utilization and does not increase unmetabolized FA (UMFA). However, a comparison of folate forms on in utero programming of offspring or maternal health has not been reported. Our objectives were to compare the effects of folate dose (low vs high) and form (FA vs 5MTHF) during pregnancy on DNAm potential, and the early and later PW phenotype of Wistar rat mothers and female offspring (mothers-to-be).

Methods

Pregnant Wistar rats (n = 22/group) were fed an AIN93G diet with recommended FA (1X, 2mg/kg diet), 5X-FA or equimolar 5MTHF. Dams were fed 1X-FA during lactation and then dams and female pups were fed a high fat diet for 19 weeks. Weight gain (WG), food intake (FI), energy expenditure (EE), insulin resistance (IR), plasma 5MTHF, UMFA, homocysteine (tHcy), and hepatic S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH) and DNA methyltransferases (DNMT) activity at birth and PW were measured.

Results

Dams fed 5MTHF diets had lower DNMT activity at birth and female pups had higher SAM: SAH ratios (P < 0.05) indicative of altered DNAm potential compared to FA diets. Plasma 5MTHF at birth was dose dependent with 5X diets leading to higher levels than 1X diets (P < 0.001) in dams and pups. In contrast, UMFA was only higher in 5X-FA dams. 5MTHF dams had higher tHcy at birth and were more IR at 1 week PW than FA fed dams (P < 0.05). In both dams and offspring, high 5MTHF also led to higher WG (> 15%, P < 0.001) and FI (> 5%, P < 0.001) compared to high FA diets up to 19 weeks. EE (P < 0.05) was higher suggesting a compensatory response to WG. 5X-MTHF dams, but not offspring, also had greater hepatic lipids (P < 0.05) than other groups.

Conclusions

Folate dose and form during pregnancy affects DNAm potential at birth and early and later phenotype of dams and female offspring. High 5MTHF increases WG, FI and hepatic lipids PW suggesting it may not be the preferred form for prenatal supplements or additions to the food supply.

Funding Sources

Supported by CIHR-INMD; EP supported by NSERC-CGS D.

Choline and Folic Acid Balance in Diets During Pregnancy Programs Food Intake Regulation in Wistar Rat Offspring (FS08-05-19)

Objectives

High gestational folic acid (FA) induces an obesogenic phenotype in male Wistar rat offspring. Imbalances between FA and other methyl-nutrients (i.e., choline) leading to perturbations in the 1-carbon cycle may account for the effects of high FA diets. Canadian women consume high (2–7-fold) intakes of FA, but most are not meeting recommended adequate intakes for choline. Choline is also absent from Canadian prenatal supplements. The objective of this study is to evaluate the effects of the interaction between choline and FA in maternal diets of rats on the 1-carbon cycle, and the programming of food intake, body weight gain and biomarkers of obesity in the offspring later in life.

Methods

Pregnant Wistar rat dams were fed the AIN-93 G diet with recommended (1X) choline and FA (RCRF, control), or a 5X FA diet with either 0.5X choline (LCHF), 1X choline (RCHF), or 2.5X choline (HCHF). Brain and blood were collected at birth. At weaning one male pup/dam from all groups was maintained on the control diet for 20 weeks then terminated. Dependent measures include weekly body weight-gain and food intake, plasma glucoregulatory hormones and 1-carbon metabolites at birth and post-weaning.

Results

Increasing choline content to 2.5-fold in a high (5-fold) gestational FA diet (HCHF) led to lower plasma insulin and leptin levels at birth compared to the LCHF and RCHF diets, respectively (P < 0.05). It also led to lower (25%, P = 0.03) plasma 5-methyltetrahydrofolate concentrations at birth compared to the RCHF diet, suggesting more efficient utilization of FA. Offspring born to dams maintained on a high folic acid diet with either low or recommended choline had higher weekly food intake (6%, P < 0.05) and body weight-gain (9%, P < 0.01). In contrast, offspring from dams fed the HCHF gestational diet were not different from those born to dams fed the RCRF (control) diet, highlighting the mitigating effects of a balanced choline and FA gestational diet.

Conclusions

Increased intakes of choline mitigate the effects of high FA diets. Maternal dietary choline interacts with FA on the long-term programming of food intake regulation in the offspring; emphasizing a need for more attention to improving choline intakes by women of child-bearing age.

Funding Sources

This research was funded by the Canadian Institute of Health Research, Institute of Nutrition, Metabolism and Diabetes (CIHR-INMD).

Maternal Choline Intake Programs Hypothalamic Energy Regulatory Pathways and Long-Term Phenotype in Male Wistar Rat Offspring (OR35-04-19)

Objectives

The prenatal period is a critical time of brain development. Maternal choline intake is associated with improvement in memory and cognitive function in the offspring. However, the role of choline in the regulation of physiological functions controlled by the hypothalamus has not been reported. The objective of this study is to elucidate the effects of choline intake on the in utero programming of hypothalamic energy regulatory neurons in male Wistar rat offspring.

Methods

Pregnant Wistar rats received an AIN-93G diet containing recommended choline (RC, 1 g/kg diet), low choline (LC, 0.5-fold), or high choline (HC, 2.5-fold). At birth, brain and blood was collected from male pups. Male pups from each dietary treatment were maintained on the control diet for 17-weeks. Dependent measures include post-weaning food intake, energy expenditure, weight-gain, plasma glucoregulatory hormones, brain choline and 1-carbon metabolite levels, and expression of hypothalamic energy regulatory neurons.

Results

At birth, pup brain concentrations of choline proportionally reflected the choline content in the maternal diets. HC pups had higher hypothalamic protein expression of the orexigenic neuropeptide-Y neuron than both groups (P < 0.05), but lower activation than LC pups (P < 0.05). Both HC and LC pups had lower plasma leptin concentrations than RC pups (P < 0.01), but LC pups had lower hypothalamic leptin receptor expression compared to both groups at birth (P < 0.05). During adulthood, offspring of HC dams had higher weekly food intake compared to RC (11%, P < 0.01), and higher weight-gain than both RC and LC groups (12%, P < 0.05). LC offspring had lower 24hr energy expenditure and locomotor activity than HC and RC groups (6%, P < 0.05).

Conclusions

Choline content of diets consumed by rats during pregnancy impacts in utero development of hypothalamic energy regulatory systems; long-term body weight-gain, food intake and energy expenditure in mature rat offspring.

Funding Sources

This research was supported by the Canadian Institute of Health Research, Institute of Nutrition, Metabolism and Diabetes (CIHR-INMD).

Dietary Intakes of Folic Acid During Pregnancy Determines Maternal Re-Set of Metabolism Post-Birth in Wistar Rat Dams (FS08-06-19)

Objectives

Nutrition during pregnancy alters the “re-set” of maternal metabolism and in turn the mother's metabolic phenotype later in life. Folic acid (FA, synthetic folate) consumed at intakes above requirements during pregnancy by rats leads to increased weight gain and altered DNA methylation in central and peripheral pathways regulating food intake. The objectives of this study were to examine the effects of intakes below and above FA dietary requirements on the re-set of energy metabolic pathways in Wistar rat mothers early post-birth.

Methods

Pregnant Wistar rats (n = 12/group) were fed an AIN93G diet with 5 levels of FA: 0X, 1X (control, 2 mg FA/kg), 2.5X, 5X or 10X. Dams were fed 1X-FA during lactation up to 1-week post-weaning (PW) when maternal metabolism is thought to re-set to homeostasis and then terminated. Weekly body weight, food intake, expression of hypothalamic food-intake neurons, mRNA and protein expression of folate-related and energy metabolic genes, and glucoregulatory hormones were measured. The homeostatic model assessment of insulin resistance (HOMA-IR) was used as a surrogate index of insulin resistance.

Results

Below (0X) and above (5X and 10X) FA requirements during pregnancy suppressed expression of hepatic folate metabolism (methyltetrahydrofolate (MTHF) reductase, and methionine synthase; P < 0.05) genes and led to higher 5-MTHF (P < 0.005) in blood compared to control suggesting dysregulation of 1-carbon pathways. Dams fed 0X- and 5X-FA also had higher plasma insulin and HOMA-IR than controls and changes in glucose and lipid metabolism-regulating genes in muscle (Glucose transporter-4, and Peroxisome-proliferator activated receptors; P < 0.05) but not liver or adipose at 1-week PW. The diets did not affect expression of hypothalamic food intake neurons nor body weight or food intake of the dams from birth to 1-week PW.

Conclusions

FA below (0X) or above (5X, 10X) requirements during pregnancy induce dysregulation of 1-carbon pathways and delay re-set of energy metabolic pathways in Wistar rat dams by 4-weeks after birth, potentially programming long-term negative metabolic effects.

Funding Sources

This research was supported by: Canadian Institute of Health Research, Institute of Nutrition, Metabolism and Diabetes (CIHR-INMD); EP supported by NSERC Alexander Graham Bell Canada Graduate Scholarships-Doctoral Program (CGS D).

Role of single serving form of dairy on satiety and postprandial glycaemia in young and older healthy adults

Dairy proteins reduce appetite and improve postprandial glycaemic response in adults. However, there are no reports of dairy in amounts usually consumed on satiety and postprandial glycaemia in either young or older adults. In a randomized crossover design, 30 healthy young adults (age: 23.5 ± 0.5 years; body mass index (BMI): 21.8 ± 0.4 kg/m²) and 30 healthy/overweight older adults (age: 65.2 ± 0.5 years; BMI: 24.7 ± 0.6 kg/m²) consumed 1 serving (according to manufacturers' labels) of skim milk (0.1% milk fat (MF)), whole milk (3.25% MF), plain Greek yogurt (2% MF), cheddar cheese (31% MF), and water (energy-free control) after a 12-h fast. Subjective appetite was measured every 15-30 min over 3 h. Blood glucose and insulin were measured at baseline and every 15-30 min over 2 h. All dairy treatments reduced post-treatment subjective appetite area under the curve (AUC) over 3 h by 8%-17% more than water. Greek yogurt reduced appetite 3-h AUC more than skim and whole milk by 9% and 7%, respectively (p < 0.0001). Post-treatment blood glucose 2-h AUC was 42% lower in young compared with older adults (p = 0.003). It was also 52%-78% lower after cheese compared with milks and yogurt (p < 0.0001). Post-treatment insulin AUC after cheese was only 10%-15% of that after milks and Greek yogurt (p < 0.0001). We conclude that single servings of dairy differ in effect on postprandial satiety and glycaemia and merit consideration in management of metabolic syndrome.

Effect of dairy and nondairy snacks on postprandial blood glucose regulation in 9-14-year-old children

In adults, dairy consumption improves short-term blood glucose regulation. It is unknown if these short-term benefits extend to children of different weight statuses. The objective of this study was to investigate the effect of a dairy and nondairy snack in both normal-weight (NW) and overweight/obese (OW/OB) children on blood glucose regulation and food intake (FI). In a repeated-measures crossover design, 11 NW and 7 OW/OB children (age: 9-14 years), consumed, in random order, a dairy (Greek yogurt, 198.9 g, 171 kcal, 0 g fat, 17 g protein) or nondairy (mini sandwich-type cookies, 37.5 g, 175 kcal, 7.5 g fat, 1.3 g protein) snack containing 25 g of available carbohydrates. Ad libitum FI was measured 120 min after snack consumption. Blood glucose, insulin, C-peptide, and glucagon-like peptide-1 (GLP-1) were measured at 0 min (before the snack), and at 30, 60, 90, and 120 min after snack consumption. Insulin secretion was calculated from deconvolution of C-peptide. Hepatic insulin extraction was calculated as C-peptide divided by insulin. FI did not differ between snacks (P = 0.55). Mean blood glucose was lower (P < 0.001) and insulin higher (P < 0.0001) in the 120 min after consuming the dairy snack. C-Peptide concentrations (P = 0.75) and insulin secretion (P = 0.37) were not different between snacks. The increase in insulin was explained by reduced hepatic insulin extraction (P < 0.01). Consumption of the dairy snack also increased mean GLP-1 concentrations (P < 0.001). In conclusion, consumption of a dairy snack by NW and OW/OB children results in reduced postprandial blood glucose concentrations and elevated circulating insulin compared with a nondairy snack possibly because of delayed hepatic insulin extraction.

Correlating in vitro digestion viscosities and bioaccessible nutrients of milks containing enhanced protein concentration and normal or modified protein ratio to human trials

In vitro digestion of cereal with high protein milks reflects the appearance of in vivo biomarkers of starch and protein digestion.

Faba bean protein flours added to pasta reduce post-ingestion glycaemia, and increase satiety, protein content and quality

Durum Wheat Semolina (DWS) pastas with added fababean (FB) protein flour reduce postprandial blood glucose and appetite and have higher nutritional quality.

The role of IL-6 in exercise-induced anorexia in normal-weight boys

Our previous study showed that interleukin-6 (IL-6) is associated with suppression of appetite after high-intensity exercise (HIEX), but an independent role in food intake (FI) was not defined. We hypothesized that IL-6 suppresses appetite and FI, independently of appetite hormones, after HIEX in normal-weight (NW) boys. We investigated the effect of HIEX, with and without the inflammation inhibitor ibuprofen (IBU), on IL-6, other biomarkers of inflammation and appetite, FI, and ratings of appetite in NW boys. Fifteen NW boys (aged 13–18 years) were randomly assigned in a crossover design to 4 sessions: (i) water and rest, (ii) IBU and rest, (iii) water and HIEX, and (iv) IBU and HIEX. HIEX consisted of three 10-min bouts of exercise at 75% of maximal oxygen uptake with 90 s of active rest between bouts. IBU (300 mg) was given as a liquid suspension. FI, ratings of appetite, and plasma biomarkers of appetite, inflammation, stress, and glucose control were measured. FI was not affected by HIEX or IBU. Appetite increased over time (p = 0.002) but was lower after HIEX (p < 0.001) and not affected by IBU. HIEX, but not IBU, resulted in higher levels of IL-6 (p < 0.001) and cortisol (p < 0.001) and lower active ghrelin (p < 0.001). IL-6 correlated with active ghrelin (r = 0.37; p = 0.036) and cortisol (r = 0.26; p = 0.049). An independent role for IL-6 in appetite suppression was not supported. However, IL-6 was correlated with active ghrelin and cortisol, thus potentially mediating appetite via these interactions.

Research and regulatory gaps for the substantiation of protein content claims on foods

Protein claims provide guidance to consumers seeking protein-rich foods. Protein claim regulations differ globally, and both Canada and the United States require protein quality assessments. A tripartite workshop identified the need to (i) harmonize, (ii) update existing amino acid composition and digestibility databases, (iii) develop non-animal bioassays, and (iv) evaluate the impact of protein claims on human health. The Protein-Digestibility Corrected Amino Acid Score method is recommended for current regulatory use in Canada.

Gestational folic acid content alters the development and function of hypothalamic food intake regulating neurons in Wistar rat offspring post-weaning

Background: Folic acid plays an important role in early brain development of offspring, including proliferation and differentiation of neural stem cells known to impact the function of food intake regulatory pathways. Excess (10-fold) intakes of folic acid in the gestational diet have been linked to increased food intake and obesity in male rat offspring post-weaning.Objective: The present study examined the effects of folic acid content in gestational diets on the development and function of two hypothalamic neuronal populations, neuropeptide Y (NPY) and pro-opiomelanocortin (POMC), within food intake regulatory pathways of male Wistar rat offspring at birth and post-weaning.Results: Folic acid fed at 5.0-fold above recommended levels (5RF) to Wistar dams during pregnancy increased the number of mature NPY-positive neurons in the hypothalamus of male offspring, compared to control (RF), 0RF, 2.5RF, and 10RF at birth. Folic acid content had no effect on expression and maturation of POMC-positive neurons. Body weight and food intake were higher in all treatment groups (2.5-, 5.0-, and 10.0-fold folic acid) from birth to 9 weeks post-weaning compared to control. Increased body weight and food intake at 9-weeks post-weaning were accompanied by a reduced activation of POMC neurons in the arcuate nucleus (ARC).Conclusion: Gestational folic acid content modulates expression of mature hypothalamic NPY-positive neurons at birth and activation of POMC-positive neurons at 9-weeks post-weaning in the ARC of male Wistar rat offspring which may contribute to higher body weight and food intake later in life.

The effect of dairy products consumed with high glycemic carbohydrate on subjective appetite, food intake, and postprandial glycemia in older adults

The objective was to compare the effect of liquid, semi-solid, and solid dairy products and a nondairy beverage when consumed with glycemic carbohydrate on subjective appetite, food intake (FI), and post-prandial glycemia (PPG) in healthy older adults. Thirty healthy men and women (14 males and 16 females; age: 64.6 ± 2.4 y; BMI: 25.6 ± 2.5 kg/m²) participated in a randomized crossover study. Treatments were one of 250 mL of 2% fat milk and soy beverage, 175 g of 2% Greek yogurt, and 30 g of Cheddar cheese consumed as part of an isocaloric (380 kcal) meal with bread and jam. Water alone served as the energy-free control for subjective appetite. At 180 min after consumption, the participants were fed an ad libitum meal to measure FI. Subjective appetite, blood glucose, and insulin were measured at baseline and at intervals both before (post-treatment) and after the meal (postmeal). Cheese and yogurt resulted in lower post-treatment blood glucose than milk and soy beverage when consumed with carbohydrate (p < 0.0001), but no differences among any treatments were observed postmeal. Treatments led to similar insulin concentrations. Post-treatment appetite was lower than after the water control for all treatments but suppressed more by cheese and yogurt compared with milk (p < 0.0001). There were no differences in FI among treatments. Cheese and yogurt increase satiety and lower PPG more than milk or a soy beverage when consumed with carbohydrate.

The effect of dairy and nondairy beverages consumed with high glycemic cereal on subjective appetite, food intake, and postprandial glycemia in young adults

The objective was to compare the effect of dairy and nondairy beverages when consumed with carbohydrate at breakfast on subjective appetite, food intake (FI), and postprandial glycemia (PPG) in healthy young adults. Twenty-six healthy males and females (13 males and 13 females; 23.0 ± 2.6 years; BMI: 22.3 ± 1.5 kg/m²) participated in a randomized crossover study. They consumed nonisocaloric amounts (250 mL) of almond beverage, soy beverage, 1% fat milk, yogurt beverage, and water (control) with cereal and 120 min later, an ad libitum meal. Subjective appetite, PPG, and insulin were measured at baseline and at intervals before and after the meal at which FI was measured. Post-treatment blood glucose was lowest following soy beverage compared with all treatments but was not different from milk (p = 0.0002). There were no differences between any other treatments. However, over the first hour, PPG for all treatments was 27% lower compared with water (p < 0.0001). Milk and yogurt beverage led to the highest insulin concentrations post-treatment (p < 0.0001) but there were no differences between treatments postmeal. All treatments reduced appetite and led to lower FI at the meal compared with water, but FI was lower after milk compared with all treatments except yogurt beverage (p < 0.0001). Both dairy and nondairy beverages consumed with a high glycemic cereal at breakfast increased satiety and decreased FI compared with water with cereal. Despite higher carbohydrate content, all beverages led to similar or lower PPG than the water breakfast, but dairy beverages increased insulin more than nondairy beverages.

Decreased Appetite after High-Intensity Exercise Correlates with Increased Plasma Interleukin-6 in Normal-Weight and Overweight/Obese Boys

Background: High-intensity exercise (HIEX) suppresses appetite in adults and is thought to be mediated by appetite-regulating hormones. However, the effects of HIEX-induced inflammatory and stress biomarkers on appetite control and body weight have not been reported in children or adults. Objective: The objective of this study was to describe the effects of acute HIEX at 70% peak oxygen consumption (VO2peak) on postexercise appetite and selective biomarkers of inflammation, stress, and appetite regulatory hormones in normal-weight (NW) and in overweight/obese boys. Methods: NW (n = 11) and overweight/obese (n = 11) boys aged 10-18 y were randomly assigned in a crossover design to either rest or HIEX. Visual analog scale appetite ratings and plasma biomarkers of appetite, inflammation, stress, and glucose control were measured after HIEX or rest. Results: Appetite increased from baseline to 110 min (P < 0.001), but was lower after HIEX (P = 0.04), with no difference between body weight groups. HIEX also resulted in lower active ghrelin (P < 0.001) and increased interleukin-6 (IL-6; P < 0.001), tumor necrosis factor-α (P < 0.001), and cortisol (P < 0.001) concentrations, independent of body weight. It increased blood glucose (P = 0.002) and insulin (P = 0.028) concentrations in NW but not overweight and obese boys. Leptin, glucagon-like peptide 1, peptide tyrosine tyrosine, C-reactive protein, and cortisol were not affected by HIEX. An inverse correlation was found between IL-6 and appetite (r = -0.379; P = 0.012), but not any other biomarkers. Conclusions: HIEX resulted in reduced appetite that correlated with an increase in IL-6 in both NW and overweight/obese boys. However, although a role for IL-6 in the response can be suggested, the suppression of appetite was potentially mediated by the decrease in active ghrelin and/or increase in cortisol. This trial was registered at clinicaltrials.gov as NCT02619461.

Pre- and within-meal effects of fluid dairy products on appetite, food intake, glycemia, and regulatory hormones in children

The effect of beverages commonly consumed by children in-between or with meals on short-term food intake (FI) and glycemic control has received little attention. Therefore, 2 experiments were conducted in 9- to 14-year-old children following a randomized repeated-measures design. Experiment 1 (n = 32) compared the effects of water (control) and isocaloric (130 kcal) amounts of 2% milk, chocolate milk, yogurt drink, and fruit punch on subjective appetite and FI. Experiment 2 (n = 20) compared the effects of isocaloric (130 kcal) amounts of 2% milk and fruit punch on subjective appetite, FI, and glycemic and appetite hormone responses. One serving of the beverages was given as a pre-meal drink at baseline (0 min) and a second serving 60 min later with an ad libitum pizza meal. Meal FI in experiment 1 was lower by 14% and 10%, respectively, after chocolate milk and yogurt drink (p < 0.001), but not milk, compared with water. Cumulative energy intake (beverages plus meal) was higher after caloric beverages than water. In experiment 2, no differences occurred in pre-meal but post-meal glucose was 83% higher in overweight/obese than normal-weight children (p = 0.02). Milk led to higher pre-meal glucagon-like peptide-1 and post-meal peptide tyrosine tyrosine (PYY) than fruit punch (p < 0.01) but insulin did not differ between treatments. In conclusion, dairy products consumed before and with a meal have more favourable effects on FI, appetite, and satiety hormones than a sugar-sweetened beverage, but all caloric beverages result in more cumulative calories than if water is the beverage.

Canned Navy Bean Consumption Reduces Metabolic Risk Factors Associated with Obesity

The high prevalence of obesity and its metabolic co-morbidities require dietitians to promote lifestyle modifications that can be effectively implemented into practice and are feasible for customers to adhere to. The objective of this study was to determine the effect of commercially available ready-to-eat canned navy beans added to the habitual diet on risk factors associated with obesity. Fourteen overweight and obese adults consumed 5 cups of canned navy beans per week for 4 weeks. The study results demonstrated that bean consumption results in reduced waist circumference in females by 2.5 cm and males by 2.1 cm (P < 0.001). The effect of beans on pulse rate, total cholesterol (TC), and low-density lipoprotein cholesterol (LDL) were sex dependent (P < 0.05). In males, pulse rate, TC, and LDL were decreased by 6.5%, 11.5%, and 18%, respectively. In females, pulse rate increased by 9.6%, and TC and LDL were relatively unchanged. There was a trend for a decreased glucose AUC (P = 0.06) in response to a glucose load. This study demonstrates that consuming 5 cups per week of ready-to-eat canned navy beans for 4 weeks reduces metabolic risk factors associated with obesity and therefore can be used as a tool in dietetic practice.

Pubertal status, pre-meal drink composition, and later meal timing interact in determining children's appetite and food intake

Puberty is a period of development that alters energy intake patterns. However, few studies have examined appetite and food intake (FI) regulation during development of puberty in children and adolescents. Therefore, the objective was to measure the effect of pubertal status on FI and subjective appetite after pre-meal glucose and whey protein drinks in 9- to 14-year-old boys and girls. In a within-subject, randomized, repeated-measures design, children (21 pre-early pubertal, 15 mid-late pubertal) received equally sweetened drinks containing Sucralose (control), glucose, or whey protein (0.75 g/kg body weight) in 250 mL of water 2 h after a standardized breakfast on 6 separate mornings. Ad libitum FI was measured either 30 or 60 min later and appetite was measured over time. In pre-early and mid-late pubertal boys and girls there was no effect of sex on total FI (kcal). Glucose and whey protein drinks reduced calorie intake similarly at 30 min. But at 60 min, whey protein reduced FI (p < 0.001) compared with control and glucose in pre-early pubertal children, but not in mid-late pubertal children. However, sex was a factor (p = 0.041) when FI was expressed per kilogram body weight. Pubertal status did not affect FI/kilogram body weight in boys, but it was 32% lower in mid-late pubertal girls than at pre-early puberty (p = 0.010). Appetite was associated with FI in mid-late pubertal children only. In conclusion, pubertal development affects appetite and FI regulation in children.

The role of alginates in regulation of food intake and glycemia: a gastroenterological perspective

Regulation of food intake through modulation of gastrointestinal responses to ingested foods is an ever-growing component of the therapeutic approaches targeting the obesity epidemic. Alginates, viscous and gel-forming soluble fibers isolated from the cell wall of brown seaweeds and some bacteria, are recently receiving considerable attention because of their potential role in satiation, satiety, and food intake regulation in the short term. Enhancement of gastric distension, delay of gastric emptying, and attenuation of postprandial glucose responses may constitute the basis of their physiological benefits. Offering physical, chemical, sensorial, and physiological advantages over other viscous and gel-forming fibers, alginates constitute promising functional food ingredients for the food industry. Therefore, the current review explores the role of alginates in food intake and glycemic regulation, their underlying modes of action and their potential in food applications.

Role of maternal vitamins in programming health and chronic disease

Vitamin consumption prior to and during pregnancy has increased as a result of proactive recommendations by health professionals, wide availability of vitamin supplements, and liberal food-fortification policies. Folic acid, alone or in combination with other B vitamins, is the most recommended vitamin consumed during pregnancy because deficiency of this vitamin leads to birth defects in the infant. Folic acid and other B vitamins are also integral components of biochemical processes that are essential to the development of regulatory systems that control the ability of the offspring to adapt to the external environment. Although few human studies have investigated the lasting effects of high vitamin intakes during pregnancy, animal models have shown that excess vitamin supplementation during gestation is associated with negative metabolic effects in both the mothers and their offspring. This research from animal models, combined with the recognition that epigenetic regulation of gene expression is plastic, provides evidence for further examination of these relationships in the later life of pregnant women and their children.