Whole grain intake in relation to body weight: from epidemiological evidence to clinical trials

Effects of a functional yogurt enriched with soluble dietary fiber or vegetable proteins on appetite profile. An acute randomized controlled clinical trial

INTRODUCTION

designing functional foods to control appetite could be a useful strategy for managing overweight and obesity. Fiber and proteins could be interesting ingredients to consider.

OBJECTIVES

to evaluate the appetite profile of two experimental yogurts (fiber-enriched [FEY] and protein-enriched [PEY]) versus a control yogurt (CY) in a group of overweight/obesity people.

MATERIAL AND METHODS

an acute, randomized, double-blind, crossover clinical trial was carried out in a group of twelve healthy overweight/obesity type I people; randomized to consume 3 yogurts in a different order for 3 acute study days. The appetite profile (1. hunger, 2. satiety, 3. fullness, 4. prospective food consumption, 5. desire to eat something fatty, salty, sweet or savoury) was assessed using a Visual Analog Scale (ranging from 0 ''not at all'' to 10 ''extremely") at 12 moments in each acute study. Additionally, total food consumption in an ad libitum lunch was assessed.

RESULTS

FEY produce a significantly lower desire to consume any food at 30 (1.50 ± 0.42) and 60 minutes (2.78 ± 0.42) after consumption compared to PEY (3.46 ± 0.53; 4.33 ± 0.54) and CY (3.27 ± 0.69; 4.0 ± 0.78) respectively (p < 0.016). Also, FEY consumption produced a higher satiety and fullness and a lower desire to ingest something fatty, salty or savory after 90 minutes consumption compared to the other products, but the difference was not significance.

CONCLUSION

FEY might be a good functional food prototype to control appetite in overweight and obese people.

Association between dietary patterns and obesity: a longitudinal prospective cohort study

OBJECTIVES

The obesity prevalence in South Korea in 2021 stood at 38.4%. South Korea faces unique challenges in providing essential and emergency guidelines for weight management because of stepping into an aging society. We aimed to determine the daily diet patterns among the general Korean population and to investigate the association between such patterns and different obesity.

STUDY DESIGN

Longitudinal prospective cohort study.

METHODS

A total of 6539 adult participants (mean age 50.8 years, 52.9% male) with normal-weight adults were included from the Ansan-Ansung cohort of 10,030 Korean adults aged 40 or older and followed for an average of 11 years. Obesity was defined according to the criteria from the Korean Society for The Study of Obesity. Baseline dietary intake was assessed using a validated 103-item food frequency questionnaire. Dietary patterns were derived from k-means cluster analysis.

RESULTS

In the multivariate analysis, referring to white rice + baechu kimchi, participants from multigrain rice + baechu kimchi showed lower HR for obesity development (waist circumference defined-obesity; HR: 0.87, 95% CI: 0.79, 0.95; body fat percentage defined-obesity; HR: 0.89, 95% CI: 0.80, 0.98). Further analysis documented that except for body fat percentage defined-obesity, consuming milk or dairy products was linked to a reduced incidence of the other three obesity (body mass index defined-obesity; HR: 0.84, 95% CI: 0.72, 0.99; waist circumference defined-obesity; HR: 0.82, 95% CI: 0.71, 0.94; waist-to-hip ratio defined-obesity; HR: 0.75, 95% CI: 0.61, 0.91).

CONCLUSIONS

Following a diet that includes multigrain rice, fermented baechu kimchi, and dairy products is linked to a decreased risk of obesity in Korean adults. Public health programs and policies could incorporate these dietary recommendations, targeting specific population groups such as schoolchildren, adults, and the elderly. Additionally, further research is needed to explore the synergistic effects of various foods and their interactions within dietary patterns on obesity outcomes.

Urinary alkylresorcinol metabolites, biomarkers of whole grain wheat and rye intake, are beneficially associated with liver fat and other fat measures

Aims: Epidemiological studies that use dietary biomarkers to investigate the association between whole grain intake and the risk of obesity are sparse. We assessed the association between urinary alkylresorcinol metabolites including 3-(3,5-dihydroxyphenyl)-1-propanoic acid (DHPPA) and 3,5-dihydroxybenzoic acid (DHBA), biomarkers of whole grain wheat and rye intake, and body fat measures. Methods: We measured urinary excretion of DHPPA and DHBA, body weight, height, and circumferences of the waist and hip at the baseline and again after 1-year in a representative sample of 306 community-dwelling adults in Huoshan, China. We also measured liver fat accumulation [indicated by the controlled attenuation parameter (CAP)] and other body composition after 1 year. Multivariate-adjusted linear models and linear mixed-effects models were used to analyze single measurement and repeated measurements, respectively. Results: Each 1 μg g-1 creatinine increase in urinary DHPPA levels was associated with 0.21%, 0.23%, 3.64%, and 4.80% decrease in body weight, body mass index (BMI), body fat mass (BFM) and visceral fat level (VFL), respectively (all P < 0.05). Higher DHBA levels were inversely associated with CAP (percentage difference per 1 μg g-1 creatinine increment: -1.98%, P < 0.05). Higher total urinary alkylresorcinol metabolite (DHPPA + DHBA) levels were associated with lower body weight, BMI, BFM, VFL, and CAP, with the percentage differences per 1 μg g-1 creatinine increment of -0.27%, -0.27%, -3.79%, -5.12%, and -2.24%, respectively (all P < 0.05). Conclusions: Our findings suggest that the intake of whole grain wheat and rye, reflected by urinary DHPPA and DHBA, is favorably associated with liver fat and other fat measures.

Association between Whole-Grain Intake and Obesity Defined by Different Anthropometric Indicators and Dose-Response Relationship Analysis among U.S. Adults: A Population-Based Study

Existing research shows an inconsistent correlation between whole-grain intake and obesity risk, with limited study on the dose-response relationship. Here, we aimed to examine this association and dose-response relationship among U.S. adults who participated in a NHANES (2003-2018). The intake of whole grain was collected and calculated from two rounds of 24 h dietary recall. Obesity was categorized based on body mass index (BMI) and waist circumference (WC). Weighted multivariable logistic regression models were used to calculate the odds of obesity according to whole-grain intake, and the dose-response relationship was modeled by restricted cubic spline regression. Among the 27,862 participants, 38.3% had general obesity, while 58.3% had abdominal obesity. After multivariate adjustment of potential confounders, the participants in the highest quintile of whole-grain intake had a lower prevalence of general obesity (OR 0.79; 95% CI 0.72-0.88) and abdominal obesity (OR 0.80; 95% CI 0.73-0.89) compared with those in the lowest category. Spline regression showed an inversely linear dose-response association between whole-grain intake and the prevalence of general obesity and abdominal obesity. In conclusion, a higher whole-grain intake was associated with lower odds of obesity, both general and abdominal. Our findings highlight the importance of increasing the whole-grain intake to prevent and manage obesity.

Whole grain intake, diet quality and risk factors of chronic diseases: results from a population-based study in Finnish adults

OBJECTIVES

Better diet quality of whole grain consumers could contribute to the associations between whole grain intake and chronic disease risk factors. We examined whole grain intake in relation to diet quality and chronic disease risk factors (anthropometrics, blood pressure, cholesterol, triglycerides, C-reactive protein and glucose) and the role of diet quality in whole grains' associations with each risk factor.

METHODS

Our data included 5094 Finnish adults who completed a validated food frequency questionnaire and participated in a health examination within the National FinHealth 2017 Study. We assessed diet quality by the modified Baltic Sea Diet Score. P trends were calculated across whole grain intake quintiles by linear regression analysis. Interactions were assessed by including an interaction term in the analyses.

RESULTS

Higher whole grain intake was associated with slightly better diet quality compared with lower intakes in both sexes (P < 0.001). Whole grain intake was inversely associated with body mass index (P < 0.001), waist circumference (P < 0.001) and total cholesterol (P = 0.02) in men. Adjusting for medication use attenuated the inverse associations with diastolic blood pressure (P = 0.06) and HDL cholesterol (P = 0.14) in men. We observed no associations in women. Diet quality did not modify the associations between whole grain intake and chronic disease risk factors.

CONCLUSIONS

Our results suggest that whole grain intake was associated with small improvements in the chronic disease risk factors in men, regardless of diet quality. The sex differences may arise from varying health associations of whole grains from different cereal sources.

Whole Grain Proso Millet (Panicum miliaceum L.) Attenuates Hyperglycemia in Type 2 Diabetic Mice: Involvement of miRNA Profile

This work aimed to investigate the hypoglycemic effects and underlying mechanism of whole grain proso millet (Panicum miliaceum L.; WPM) on type 2 diabetes mellitus (T2DM). The results showed that WPM supplementation significantly reduced fasting blood glucose (FBG) and serum lipid levels in T2DM mice induced by a high-fat diet (HFD) combined with streptozotocin (STZ), with improved glucose tolerance, liver and kidney injury, and insulin resistance. In addition, WPM significantly inhibited the expression of gluconeogenesis-related genes G6pase, Pepck, Foxo1, and Pgc-1α. Further study by miRNA high-throughput sequencing revealed that WPM supplementation mainly altered the liver miRNA expression profile of T2DM mice by increasing the expression of miR-144-3p_R-1 and miR-423-5p, reducing the expression of miR-22-5p_R-1 and miR-30a-3p. GO and KEGG analyses showed that the target genes of these miRNAs were mainly enriched in the PI3K/AKT signaling pathway. WPM supplementation significantly increased the level of PI3K, p-AKT, and GSK3β in the liver of T2DM mice. Taken together, WPM exerts antidiabetic effects by improving the miRNA profile and activating the PI3K/AKT signaling pathway to inhibit gluconeogenesis. This study implies that PM can act as a dietary supplement to attenuate T2DM.

Effect of autoclave-cooling cycles combined pullulanase on the physicochemical and structural properties of resistant starch from black Tartary buckwheat

A starch-rich portion is produced as a by-product of black Tartary buckwheat processing. The effect of enzymatic combined with autoclaving-cooling cycles (one, two, or three times) on the physicochemical and structural properties of black Tartary buckwheat type 3 resistant starch (BRS) was evaluated. The autoclaving-cooling cycles enhanced solubility and reduced swelling, with the BRS content increasing from 14.12% to 25.18%. The high crystallinity of the BRS reflected a high molecular order. However, increasing the number of autoclaving-cooling cycles did not result in higher BRS content. The highest BRS yield in the autoclaved starch samples was 25.18% after double-autoclaving-cooling cycles. Furthermore, the autoclaving-cooling cycles altered the crystalline structure of black Tartary buckwheat, and the subsequent crystallinity changed from 36.33% to 42.05% to 38.27%. Fourier-transform infrared spectroscopy shows that the number of cycles results in more efficient double-helical packing within the crystalline lamella. Principal component analysis showed that the autoclaving-cooling cycle treatment leads to significant changes in the molecular structure of resistant starch (RS). These results indicated that autoclaving-cooling cycles might be a feasible way for producing RS from black Tartary buckwheat starch with better structural stability to expand their application range.

Characterization and application of a novel xylanase from Halolactibacillus miurensis in wholewheat bread making

The presence of arabinoxylan in wholewheat flour affects its quality significantly. Here, an efficient arabinoxylan hydrolytic enzyme, Hmxyn, from Halolactibacillus miurensis was identified and heterologously expressed in pichia pastoris. Moreover, its relevant properties, including potential application in the wholewheat bread were evaluated. Recombinant Hmxyn exhibited maximal activity at 45°C and pH 6.5, and was stable at mid-range temperature (&lt;55°C) and pH (5.5–8.0) conditions. Hmxyn had a clear hydrolysis effect on wheat arabinoxylan in dough and caused the degradation of the water-unextractable arabinoxylan, which increased the content of wheat soluble arabinoxylan of dough. The fermentation characteristics results and microstructure analysis revealed that Hmxyn improved the organizational structure and air holding capacity of fermented dough, thus promoting the dough expansion. Baking experiments further showed that Hmxyn significantly increased specific volume- and texture-linked properties of wholewheat breads. This study indicates the application potential of Hmxyn in the preparation of wholewheat bread.

The association of Carbohydrate Quality Index with cardiovascular disease risk factors among women with overweight and obesity: A cross-sectional study

Purpose

Diet is one of the most important factors influencing cardiovascular disease (CVD). The negative relationship between carbohydrate intake with lipid profiles and body weight has been previously investigated. However, this is the first study seeking to assess the association of carbohydrate quality index (CQI) with CVD risk factors.

Methods

This cross-sectional study was conducted on 291 Iranian overweight and obese women, with a body mass index (BMI) ranging between 25 and 40 kg/m², and aged 18–48 years. CQI scores were calculated by using a validated 168-item semi-quantitative food frequency questionnaire (FFQ). Biochemical and anthropometric measures were assessed using standard methods, and bioelectrical impedance was used to measure body composition.

Results

We observed that fruits (P < 0.001), vegetables (P < 0.001), and protein (P = 0.002) intake were higher in participants with a higher score of the CQI. When we adjusted for potential confounders, we observed that the CQI was negatively related to systolic blood pressure (SBP) (β = −6.10; 95% CI = −10.11, −2.10; P = 0.003) and DBP (β = −3.11; 95% CI = −6.15, −0.08; P = 0.04). Also, greater adherence to a high CQI dietary pattern, compared to the reference group, was negatively related to HOMA-IR (β = −0.53; 95% CI = −0.94, −0.12) (P for trend = 0.01), WC (β = −3.18; 95% CI = −6.26, −0.10) (P for trend = 0.04), BMI (β = −1.21; 95% CI = −2.50, 0.07) (P for trend = 0.06), and BF (β = −2.06; 95% CI = −3.82, −0.30) (P for trend = 0.02).

Conclusion

In line with previous studies, the CQI was inversely associated with blood pressure, WC, BMI, and BF. Further prospective and clinical trial studies are suggested to confirm these data.

The Impact of Cereal Grain Composition on the Health and Disease Outcomes

Whole grains are a pivotal food category for the human diet and represent an invaluable source of carbohydrates, proteins, fibers, phytocompunds, minerals, and vitamins. Many studies have shown that the consumption of whole grains is linked to a reduced risk of cancer, cardiovascular diseases, and type 2 diabetes and other chronic diseases. However, several of their positive health effects seem to disappear when grains are consumed in the refined form. Herein we review the available literature on whole grains with a focus on molecular composition and health benefits on many chronic diseases with the aim to offer an updated and pragmatic reference for physicians and nutrition professionals.

Added Fructose in Non-Alcoholic Fatty Liver Disease and in Metabolic Syndrome: A Narrative Review

Non-alcoholic fatty liver disease (NAFLD) represents the most common chronic liver disease and it is considered the hepatic manifestation of metabolic syndrome (MetS). Diet represents the key element in NAFLD and MetS treatment, but some nutrients could play a role in their pathophysiology. Among these, fructose added to foods via high fructose corn syrup (HFCS) and sucrose might participate in NAFLD and MetS onset and progression. Fructose induces de novo lipogenesis (DNL), endoplasmic reticulum stress and liver inflammation, promoting insulin resistance and dyslipidemia. Fructose also reduces fatty acids oxidation through the overproduction of malonyl CoA, favoring steatosis. Furthermore, recent studies suggest changes in intestinal permeability associated with fructose consumption that contribute to the risk of NAFLD and MetS. Finally, alterations in the hunger–satiety mechanism and in the synthesis of uric acid link the fructose intake to weight gain and hypertension, respectively. However, further studies are needed to better evaluate the causal relationship between fructose and metabolic diseases and to develop new therapeutic and preventive strategies against NAFLD and MetS.

Biological Functions and Activities of Rice Bran as a Functional Ingredient: A Review

Rice bran (RB) is a nutrient-rich by-product of the rice milling process. It consists of pericarp, seed coat, nucellus, and aleurone layer. RB is a rich source of a protein, fat, dietary fibers, vitamins, minerals, and phytochemicals (mainly oryzanols and tocopherols), and is currently mostly used as animal feed. Various studies have revealed the beneficial health effects of RB, which result from its functional components including dietary fiber, rice bran protein, and gamma-oryzanol. The health effects of RB including antidiabetic, lipid-lowering, hypotensive, antioxidant, and anti-inflammatory effects, while its consumption also improves bowel function. These health benefits have drawn increasing attention to RB in food applications and as a nutraceutical product to mitigate metabolic risk factors in humans. This review therefore focuses on RB and its health benefits.

T. Clark C, Shab-Bidar S. Association between carbohydrate quality index and general and central obesity in adults: A population-based study in Iran

Introduction: To determine whether dietary carbohydrates quality index (CQI), glycemic index, and glycemic load is associated with general and abdominal obesity.

Methods: 850 participants, 20 to 59 years old, were enrolled in a cross-sectional study from five Tehran districts through health houses. The 168 items in the semi--quantitative food frequency questionnaire were used to assess dietary intake. The CQI was calculated by using the following four components: glycemic index, total fiber, solid carbohydrate to total carbohydrate ratio, and whole grains: total grains ratio.

Results: After adjusting for confounding factors, the chance of obesity in men (OR=0.38, 95% CI 0.15to 0.95; P =0.04) measured by waist circumference (WC) was significantly lower in the fourth quintile of CQI in comparison with the first quintile. In addition, OR for obesity in men (OR=2.53, 95% CI0.52 to 1.37; P =0.04) was significantly 2.5 times higher among those in the fourth quintile of glycemic index compared with those in the lowest quintile. There was no significant association between dietary carbohydrates with general obesity in men and women.

Conclusion: In summary, dietary CQI is significantly inversely related to central obesity in men,according to this study. Additionally, adherence to a diet with a higher glycemic index in men is positively associated with central obesity.

Carbohydrates: Separating fact from fiction

The role of carbohydrate in a healthy diet has been controversial. The confusion over carbohydrate has come from the long standing limitation of dietary recall studies as well as inability in many of these studies to delineate between the different types of carbohydrates. It is the aim of this paper, to understand and review the data on the role of carbohydrate as pertaining to weight, insulin resistance, diabetes, inflammation, lipids, as well as epidemiological data on long-term cardiovascular outcome and all-cause mortality. We have reviewed the latest epidemiological and intervention studies on fiber, whole grain, and refined carbohydrates on weight, diabetes, lipids as well as major adverse cardiac events that we deemed were scientifically rigorous. High intakes of dietary fiber and whole grains are associated with positive effects on metabolic health while diet high in sugar and refined carbohydrates have negative effects on cardiometabolic health. Consistent evidence indicates that low fat and low carbohydrate diets at comparable energy levels have similar effects on body weight. Large epidemiological studies show when carbohydrates are substituted for animal-derived fat or protein mortality increased while carbohydrate exchanged with plant based protein was associated with mortality reduction. Types of carbohydrate appear to be critical for mortality and cardiovascular events. Evidence shows that quality of the carbohydrate determine cardiometabolic health and cardiovascular events. Given that most people worldwide currently consume less than 20 g of dietary fiber per day with persistently high consumption of refined carbohydrates, current evidence emphasize the need for additional measures to increase the amount and the diversity of fiber intake for improvement of cardiometabolic and cardiovascular outcomes.

Whole grain intake favorably affects blood glucose and serum triacylglycerols in overweight and obese children: A randomized controlled crossover clinical trial

OBJECTIVES

The aim of this study was to determine the effects of whole grain consumption on the metabolic profiles of overweight or obese children.

METHODS

This was a randomized crossover clinical trial with 44 overweight or obese girls. After a 2-wk run-in period, girls were randomly assigned to either intervention or control groups. Participants in the intervention group were asked to obtain 50% of their grain servings from whole grain foods each day for 6 wk. Those in the control group were asked not to consume any of these foods. A 4-wk washout period was applied following which participants were crossed over to the alternate arm. Fasting blood samples were taken before and after each phase of study.

RESULTS

Mean (± SD) age and body mass index was 11.2 ± 1.49 y and 23.5 ± 2.5 kg/m², respectively. Mean whole grain intake in intervention and control groups throughout the study was 26.5 and 3.7 g/d, respectively (P = 0.01). Whole grain consumption resulted in lower concentrations of plasma glucose (changes from baseline in intervention group: -0.10 versus 0.21 mmol/L in control group, P = 0.01), serum triacylglycerols (changes from baseline in intervention group: -0.18 versus 0.08 mmol/L in control group, P = 0.01) and higher concentrations of serum high-density lipoprotein cholesterol (changes from baseline in intervention group: 0.16 versus -0.14 mmol/L in control group, P = 0.05) after 6 wk of intervention. No effects of whole grain intake on serum concentrations of total- and low-density lipoprotein cholesterol or on blood pressure were found.

CONCLUSION

This study provided evidence supporting the beneficial effects of whole grain foods on serum concentrations of glucose, triacylglycerols and high-density lipoprotein cholesterol in overweight children.

Effects of Whole Grain Intake, Compared with Refined Grain, on Appetite and Energy Intake: A Systematic Review and Meta-Analysis

Results from observational studies indicate that whole grain (WG) intake is inversely associated with BMI and risk of weight gain. WG intake may influence energy balance and body composition through effects on appetite and energy intake. To evaluate the impact of WG food consumption on appetite and energy intake, a systematic review and meta-analysis was performed of results from randomized controlled trials (RCTs) assessing WG food consumption, appetite, and energy intake in adults. A search of PubMed, Scopus, and Food Science and Technology Abstracts yielded 36 RCTs measuring subjective appetite ratings after consuming WG foods compared with refined grain (RG) controls. Thirty-two of these studies reported AUCs for subjective appetite (hunger, fullness, satiety, desire to eat, or prospective consumption) and/or energy intake and were included in the meta-analysis. Pooled estimates from meta-analyses are expressed as standardized mean differences (SMDs). Compared with RG foods, intake of WG foods resulted in significant differences in AUCs for subjective hunger (SMD: -0.34; 95% CI: -0.46, -0.22; P < 0.001), fullness (SMD: 0.49; 95% CI: 0.31, 0.66; P < 0.001), satiety (SMD: 0.33; 95% CI: 0.18, 0.47; P < 0.001), and desire to eat (SMD: -0.33; 95% CI: -0.46, -0.20; P < 0.001). There were small, nonsignificant reductions in prospective consumption ratings (P = 0.08) and energy intake (P = 0.07) with WG intake compared with RG. These results support the view that consumption of WG foods, compared with RG foods, significantly impacts subjective appetite, and might partly explain the inverse associations between WG food intake and risk of overweight, obesity, and weight gain over time. PROSPERO registration: CRD42020148217.

The effects of whole grain intake on anthropometric measures in overweight and obese children: a crossover randomised clinical trial

Whole-grain foods have been reported to affect body weight and satiety. However, we are aware of no study in this regard among children. The present study aimed to determine the effects of whole grain consumption on anthropometric measures in overweight or obese children. In this randomised crossover clinical trial, forty-four overweight or obese girls participated. After a 2-week run-in period, subjects were randomly assigned to either intervention (n 44) or non-intervention (n 44) groups. Subjects in the intervention group were given a list of whole-grain foods and were asked to obtain half of their grain servings from these foods each day for 6 weeks. Individuals in the non-intervention group were asked not to consume any of these foods. A 4-week washout period was applied. Then, participants were crossed over to the alternate arm. The measurements were done before and after each phase. Mean age, weight and BMI of participants were 11·2 (sd 1·49) years, 51·2 (sd 10·2) kg and 23·5 (sd 2·5) kg/m2, respectively. Despite the slight reduction in weight and BMI, there were no significant differences in changes in these anthropometric measures. We found a significant effect of whole grain intake on waist circumference (−2·7 v. 0·3 cm, P = 0·04). No significant changes in hip circumference were observed. Changes in the prevalence of overweight, obesity and abdominal obesity were not significantly different. This study indicated a beneficial effect of whole-grain foods on waist circumference in overweight children; however, these foods did not influence weight and BMI.

Effects of anabaena lipoxygenase on whole wheat dough properties and bread quality

The effects of the purified recombinant anabaena lipoxygenase (ana-rLOX) on the rheological characteristics of whole wheat dough and the quality of bread were investigated. The lightness of whole wheat dough supplemented with ana-rLOX was improved, which is superior to that of dough treated with benzoyl peroxide. The effect of ana-rLOX on the strength of dough was analyzed by farinograph, extensograph, and dynamic rheological tests. Compared with the control, the stability time of dough treated with 40 IU/g ana-rLOX increased by 35.4% and the farinograph quality number increased by 27.4%. In addition, the resistance to extension, as well as the elastic and viscous modulus, was improved by ana-rLOX in a dose-dependent manner. The height and specific volume of bread treated with ana-rLOX increased by 17.3 and 15.2%, respectively, compared with the control, and the lightless, whiteness, and other textural parameters, such as hardness, springiness, chewiness, resilience, and gumminess, were significantly improved. Overall, the results of this study suggest the promising application of ana-rLOX in enhancing quality of whole wheat flour.

Perspective: Whole and Refined Grains and Health-Evidence Supporting "Make Half Your Grains Whole"

Research-based dietary guidelines suggest that consumers "make half their grains whole." Yet some advocate ingesting only whole-grain foods (WGFs) and avoiding all refined-grain foods (RGFs). Some even recommend avoiding all grain-based foods (GBFs). This article will provide arguments to counter negative deductions about GBFs and RGFs, especially staple ones, and to support dietary guidance recommending a balance of GBFs-achieved through the right mix, type, and quantity of WGFs and RGFs. Studies looking at early mortality, body weight, and glucose tolerance and diabetes will be used as examples to characterize the literature about GBFs. The following issues are highlighted: 1) inconsistent findings between epidemiological and interventional studies and impacts of GBFs on health outcomes, and the underreporting of findings showing RGFs neither raise nor lower health risks; 2) multiple confounding and potential interactions make adequate statistical adjustment difficult; 3) nonuniform WGF definitions among studies make comparison of results challenging, especially because some WGFs may contain 49-74% refined grain (RG); 4) binary categorization of GBFs creates bias because nearly all categories of WGFs are recommended, but nearly half the RGF categories are not; 5) ingestion of >5 (30-g) servings RGFs/d and <1 serving WFGs/d creates dietary imbalance; 6) pattern names (e.g., "white bread") may impugn RGFs, when names such as "unbalanced" or "few fruits and vegetables" may more fairly characterize the dietary imbalance; 7) avoidance of all enriched RGs may not only impair status of folate and other B vitamins and certain minerals such as iron and zinc but also decrease acceptability of WGFs; 8) extrapolation beyond median documented intakes in high-WGF consumers (∼48 g whole grain/d) in most cohorts is speculative; 9) recommended dietary patterns such as the Mediterranean diet demonstrate that the right mix of WGFs and RGFs contributes to positive health outcomes.

Whole-Grain Consumption Does Not Affect Obesity Measures: An Updated Systematic Review and Meta-analysis of Randomized Clinical Trials

Since the release of a previous meta-analysis on the effect of whole-grain intake on obesity measures, several clinical trials have been published. Therefore, we aimed to update the previous meta-analysis on the effect of whole-grain intake on obesity measures by including recently published studies, as well as considering the main limitations in that analysis. We searched the online databases of PubMed, Scopus, Clarivate Web of Science, EmBase, and Google Scholar for relevant studies published up to February 2019, using relevant keywords. Randomized clinical trials investigating the effect of whole-grain products or diets high in whole-grain foods, compared with a control diet, on anthropometric measures [including body weight, BMI, waist circumference, and fat mass (FM)] were included. In total, 21 studies with a total sample of 1798 participants, aged ≥18 years, were considered. Based on 22 effect sizes from 19 studies on body weight, with a total sample of 1698 adults, we found no significant effect of whole-grain consumption on body weight. The same findings were obtained for BMIs, such that using 10 effect sizes from 10 clinical trials with a total sample of 769 individuals we did not find any significant effect. With regards to body fat percentage [weighted mean difference (WMD): 0.27; 95% CI: -0.05 to 0.58%; P = 0.09], FM (WMD: 0.45; 95% CI: -0.12 to 1.02 kg; P = 0.12), fat-free mass (WMD: 0.31; 95% CI: -0.67 to 0.06 kg; P = 0.10), and waist circumference (WMD: 0.06; 95% CI: -0.50 to 0.63 cm; P = 0.82), we failed to find any significant effect of whole-grain consumption. In conclusion, our findings did not support current recommendations of whole-grain intake in attempts to control obesity measures. Given the beneficial effects of whole-grain intake on other measures of human health, additional well-designed studies are required to further investigate the effect on obesity. The protocol has been registered with PROSPERO (registration number CRD42019125320).

Breakfast consumption and obesity among preadolescents: An epidemiological study

BACKGROUND

This study aimed to examine the association between breakfast consumption and childhood weight status, in relation to various socioeconomic and lifestyle factors.

METHODS

A cross-sectional survey was conducted including 1,728 children aged 10-12 years and their parents, during the school years 2014-2016. Primary schools from five Greek counties (including the Athens metropolitan area) were randomly selected. Parental and child data were collected through self-administered, anonymous questionnaires. Children's weight status was based on gender- and age-specific tables derived from the International Obesity Task Force body mass index cutoffs. Logistic regression was used to determine the association between frequency and type of breakfast consumption and children's weight status.

RESULTS

The frequency of breakfast consumption was not associated with childhood overweight or obesity, even when other factors were included in the analysis like sex, age, physical activity, meals / day, family annual income, parental weight status, parental physical activity level, parental educational level and parental employment status. From the nine foods that were included only the consumption of bread or rusks and chocolate milk were found to have a negative association with childhood overweight or obesity (odds ratio: 0.51; 95% CI: 0.34, 0.79 and OR: 0.50; 95% CI: 0.28, 0.87, respectively).

CONCLUSIONS

The result that frequency of breakfast consumption was not associated with children's overweight / obesity may lead to a deeper investigation of the foods consumed during breakfast. Bread or rusks and chocolate milk seemed to have a protective effect; further nutritional analysis is needed to explore the potential mechanisms of this observation.

Association between Adherence to the Mediterranean Diet and Physical Fitness with Body Composition Parameters in 1717 European Adolescents: The AdolesHealth Study

Obesity, low levels of physical fitness, and unhealthy eating patterns are responsible for part of the health problems of adolescents today. The current study aimed at examining the association between the adherence to the Mediterranean diet (MD), through each answer to the items of the Adherence to the MD Questionnaire (KIDMED), and physical fitness with body composition parameters (body mass index (BMI), percentage of body fat, and waist circumference) in 1717 European adolescents (N = 900 boys, N = 817 girls). Data of body composition, physical fitness results, and the answers to KIDMED were analyzed by the Student’s t-test. Additionally, the effect size (ES) was calculated and a Chi-square test analyzed the proportion of participants with and without over waist circumference, overfat, and overweight in each KIDMED question. The relative risk of suffering over waist circumference, overfat and overweight in relation to the responses was calculated by Odd-Ratio. Adherence to the MD did not influence the condition of over waist circumference, overfat and overweight, although certain dietary habits were identified as risk factors for their development. Over waist circumference, overfat, and overweight boys and girls presented higher levels of body mass, waist circumference, body fat percentage, and BMI (p < 0.001; ES = 1.73–3.38), as well as lower levels of all the parameters of the physical fitness analyzed (p < 0.001; ES = 0.45–1.08), except the handgrip test. A direct relationship between fitness and over waist circumference, overfat, and overweight was found.

Association between Carbohydrate Quality Index and general and abdominal obesity in women: a cross-sectional study from Ghana

OBJECTIVES

The relationships between carbohydrate intake and risk of obesity have been widely investigated. However, there are limited data on the associations between their relative proportions and quality contained in the same diet on risk of obesity, especially in low-income and middle-income countries. The aim of this study was to assess the relationship between an overall Carbohydrate Quality Index (CQI) and general and abdominal obesity in women.

SETTING AND PARTICIPANTS

In this cross-sectional study, data from 277 women in Ghana were analysed. Dietary information was obtained from 2-day 24 hours dietary recalls. CQI was calculated from the four indices dietary fibre, Glycaemic Index, whole grains/total grains ratio and solid carbohydrates/total carbohydrates ratio.

OUTCOME MEASURES

Body mass index, waist circumference (WC), waist-to-height ratio (WHtR) and Conicity Index were measured.

RESULTS

After adjusting for covariates, the chance for general obesity (OR 0.25, 95% CI 0.10 to 0.65) and abdominal obesity measured by WC (OR 0.22, 95% CI 0.08 to 0.58) were significantly lower in the topmost quintile of CQI in comparison with the lowest quintile. In addition, the OR for higher WHtR (OR 0.27, 95% CI 0.11 to 0.69) was significantly lower among participants in the fifth quintile of CQI compared with those in the first quintile.

CONCLUSIONS

The present study demonstrates that there is an inverse association between dietary CQI and both general and abdominal obesity. These findings suggest that CQI may be used for the improvement of dietary intake to prevent obesity.

The Relationship between Whole Grain Intake and Body Weight: Results of Meta-Analyses of Observational Studies and Randomized Controlled Trials

Results from some observational studies suggest that higher whole grain (WG) intake is associated with lower risk of weight gain. Ovid Medline was used to conduct a literature search for observational studies and randomized controlled trials (RCTs) assessing WG food intake and weight status in adults. A meta-regression analysis of cross-sectional data from 12 observational studies (136,834 subjects) and a meta-analysis of nine RCTs (973 subjects) was conducted; six prospective cohort publications were qualitatively reviewed. Cross-sectional data meta-regression results indicate a significant, inverse correlation between WG intake and body mass index (BMI): weighted slope, −0.0141 kg/m² per g/day of WG intake (95% confidence interval (CI): −0.0207, −0.0077; r = −0.526, p = 0.0001). Prospective cohort results generally showed inverse associations between WG intake and weight change with typical follow-up periods of five to 20 years. RCT meta-analysis results show a nonsignificant pooled standardized effect size of −0.049 kg (95% CI −0.297, 0.199, p = 0.698) for mean difference in weight change (WG versus control interventions). Higher WG intake is significantly inversely associated with BMI in observational studies but not RCTs up to 16 weeks in length; RCTs with longer intervention periods are warranted.

Plant-Based Diets in Hispanic/Latino Adult Adventists in the United States and Their Association With Body Mass Index

PURPOSE

To characterize plant-based dietary practices and examine their relationship with body mass index (BMI) in Hispanic/Latino Seventh-day Adventists (SDA).

DESIGN

Cross-sectional analyses of data among Hispanics/Latinos in the Adventist Health Study-2 (AHS-2).

SETTING

The AHS-2 is a cohort of SDA adults (n = 96 592) in North America.

PARTICIPANTS

A total of 3475 Hispanics/Latinos who provided demographic, dietary, anthropometric, and lifestyle data at enrollment.

MEASURES

Plant-based dietary practices were determined from food frequency questionnaire; BMI, demographic, and lifestyle data were assessed by questionnaire.

ANALYSIS

In linear regression analysis, plant-based diets were modeled as dummy variables with nonvegetarian as the referent group and log(BMI) as the outcome adjusted for age, sex, education, exercise, nativity, alcohol use, smoking, and energy intake.

RESULTS

We identified 202 vegans, 664 vegetarians, 409 pesco-vegetarians, 227 semi-vegetarians, and 1973 nonvegetarians. Compared to the nonvegetarian referent (BMI = 27.50), estimated BMI were lower among vegans (23.58, P < .0001), vegetarians (25.24, P < .0001), pesco-vegetarians (26.36, P = .0002), and semi-vegetarians (26.69, P = .130). Other factors associated with lower BMI were being female (P = .001), nativity (Mexico, P = .002; South America, P < .0001; Caribbean, P = .004), having a college degree or higher (P = .01), exercise (P < .0001), and never smoked (P = .0006).

CONCLUSION

Hispanic/Latino SDAs who consumed plant-based diets had lower BMI than nonvegetarians. The application of a plant-based diet as practiced by the Hispanic/Latino Adventists in this population may have public health impact on US Hispanic/Latinos.

Wholegrain Intake and Risk of Type 2 Diabetes: Evidence from Epidemiological and Intervention Studies

Type 2 diabetes mellitus (T2DM) is one of the most common metabolic diseases and represents a leading cause of morbidity and mortality because of its related complications. The alarming rise in T2DM prevalence worldwide poses enormous challenges in relation to its social, economic, and a clinical burden requiring appropriate preventive strategies. Currently, lifestyle modifications—including approaches to promote a moderate body weight reduction and to increase regular physical exercise—are the first crucial intervention for T2DM prevention. In the light of the difficulty in reducing body weight and in long-term maintenance of weight loss, quality changes in dietary patterns—in terms of macro and micronutrient composition—can also strongly affect the development of T2DM. This may provide a more practical and suitable preventative approach than simply implementing caloric restriction. Along this line, there is increasing evidence that wholegrain consumption in substitution of refined grains is associated with a reduction of the incidence of several non-communicable chronic diseases. The aim of the present review is to summarize the current evidence from observational and randomized controlled clinical trials on the benefits of wholegrain on T2DM prevention and treatment. Plausible mechanisms by which wholegrain could act on glucose homeostasis and T2DM prevention are also evaluated. Altogether, the totality of the available evidence supports present dietary recommendations promoting wholegrain foods for the prevention and treatment of T2DM.

Contaminants in Grain-A Major Risk for Whole Grain Safety?

Grains are the main energy and carbohydrate sources for human nutrition globally. Governmental and non-governmental authorities recommend whole grains as a healthy food choice. The role of contaminants in (whole) grains and how to mitigate any potential risk following their consumption has not been reported. With this narrative review, we shed light on the potential human health risk from contaminants in whole grains and elaborate strategies to mitigate such risk. We found that grains represent a significant source of food-borne contaminants, the main ones being; mycotoxins including (A) aflatoxin B1; (B) ochratoxin A; (C) fumonisin B1; (D) deoxynivalenol; (E) zearalenone; toxic metals like arsenic, cadmium and lead; as well as process contaminants such as acrylamide. Whole grains usually contain more contaminants than refined products. However, whole grains also provide more nutrients that may reduce the impact of these contaminants. Strict regulatory thresholds aim to minimize the risk of contaminants to public health. The consumer can further impact on the mitigation of any risk by eating a healthy diet filled with nutrient-dense foods such as whole grains and probiotics. The risk posed by contaminants from whole grains do not outweigh the known nutritional benefits of whole grain consumption.

Dietary Fibre as a Unifying Remedy for the Whole Spectrum of Obesity-Associated Cardiovascular Risk

Obesity is a pandemic carrying the heavy burden of multiple and serious co-morbidities including metabolic syndrome, type 2 diabetes and cardiovascular diseases. The pathophysiological processes leading to the accumulation of body fat slowly evolve to fat accumulation in other body compartments than subcutaneous tissue. This abnormal fat deposition determines insulin resistance which in turn causes blood glucose and lipid metabolism derangement, non-alcoholic fatty liver disease, hypertension, and metabolic syndrome. All these conditions contribute to increase the cardiovascular risk of obese people. Several randomized clinical trials demonstrated that moderate weight loss (5⁻10%) in obese patients improves obesity-related metabolic risk factors and coexisting disorders. Therefore, nutritional strategies able to facilitate weight management, and in the meantime positively influence obesity-associated cardiovascular risk factors, should be implemented. To this aim, a suitable option could be dietary fibres that may also act independently of weight loss. The present narrative review summarizes the current evidence about the effects of dietary fibres on weight management in obese people. Moreover, all of the different cardiovascular risk factors are individually considered and evidence on cardiovascular outcomes is summarized. We also describe the plausible mechanisms by which different dietary fibres could modulate cardio-metabolic risk factors. Overall, despite both epidemiological and intervention studies on weight loss that show statistically significant but negligible clinical effects, dietary fibres seem to have a beneficial impact on main pathophysiological pathways involved in cardiovascular risk (i.e., insulin resistance, renin-angiotensin, and sympathetic nervous systems). Although the evidence is not conclusive, this suggests that fibre would be a suitable option to counteract obesity-related cardio-metabolic diseases also independently of weight loss. However, evidence is not consistent for the different risk factors, with clear beneficial effects shown on blood glucose metabolism and Low Density Lipoprotein (LDL) cholesterol while there is fewer, and less consistent data shown on plasma triglyceride and blood pressure. Ascribing the beneficial effect of some foods (i.e., fruits and vegetables) solely to their fibre content requires more investigation on the pathophysiological role of other dietary components, such as polyphenols.

Ferulic acid may target MyD88-mediated pro-inflammatory signaling - Implications for the health protection afforded by whole grains, anthocyanins, and coffee

Higher dietary intakes of anthocyanins have been linked epidemiologically to decreased risk for metabolic syndrome, type 2 diabetes and cardiovascular events; clinical trials and rodent studies evaluating ingestion of anthocyanin-rich extracts confirm favorable effects of these agents on endothelial function and metabolic syndrome. However, these benefits of anthocyanins are lost in rats whose gut microbiome has been eliminated with antibiotic treatment - pointing to bacterial metabolites of anthocyanins as the likely protective agents. A human pharmacokinetic assessment of orally administered cyanidin-3-O-glucoside, a prominent anthocyanin, has revealed that, whereas this compound is minimally absorbed, ferulic acid (FA) is one of its primary metabolites that appears in plasma. FA is a strong antioxidant and phase 2 inducer that has exerted marked anti-inflammatory effects in a number of rodent and cell culture studies; in particular, FA is highly protective in rodent models of diet-induced weight gain and metabolic syndrome. FA, a precursor for lignan synthesis, is widely distributed in plant-based whole foods, mostly in conjugated form; whole grains are a notable source. Coffee ingestion boosts plasma FA owing to gastrointestinal metabolism of chlorogenic acid. Hence, it is reasonable to suspect that FA mediates some of the broad health benefits that have been associated epidemiologically with frequent consumption of whole grains, anthocyanins, coffee, and unrefined plant-based foods. The molecular basis of the anti-inflammatory effects of FA may have been clarified by a recent study demonstrating that FA can target the adaptor protein MyD88; this plays an essential role in pro-inflammatory signaling by most toll-like receptors and interleukin-1β. If feasible oral intakes of FA can indeed down-regulate MyD88-dependent signaling, favorable effects of FA on neurodegeneration, hypothalamic inflammation, weight gain, adipocyte and beta cell function, adiponectin secretion, vascular health, and cartilage and bone integrity can be predicted. Since FA is well tolerated, safe, and natural, it may have great potential as a protective nutraceutical, and clinical trials evaluating its effects are needed.

Subjective feelings of appetite of wholegrain breakfasts evaluated under controlled, laboratory and 'at home' conditions

BACKGROUND

Appetite regulating properties of foods are usually investigated under laboratory conditions, whereas in real life, foods are consumed under at home conditions. The objective of this study was to compare the acute effects of breakfasts when tested in a laboratory condition and in an at home condition. Appetite regulating properties of two bread breakfasts and two cereal breakfasts were also compared.

SUBJECTS AND METHODS

In this randomized cross-over trial balanced for laboratory and at home test conditions, thirty-two women consumed five breakfasts, i.e. two bread breakfasts, two cereal breakfasts and one fried-egg breakfast. Visual analogue scales for measuring appetite were captured via an on-line scoring system and were analyzed as incremental area under the curve, as satiation phase and as satiety phase.

RESULTS

Location effects were limited to two small effects only. An overall location effect in hunger feelings was observed (p = 0.040), which occurred specifically during the short satiation period (p = 0.0002) where hunger feelings scored higher under laboratory conditions. Similarly, a location effect was observed for desire to eat (p = 0.001); this was again higher under laboratory conditions. No other location effects were observed. Bread breakfasts did not differ in their appetite regulating properties. The Steel Cut oatmeal breakfast was reported to be more satiating (p = 0.001) as compared to the ready-to-eat cereal.

CONCLUSIONS

Whereas the five breakfasts varied somewhat in their appetite regulating properties, evaluation under laboratory conditions overall did not result in different appetite scores compared to the at home conditions. This suggests that at home testing may be a useful alternative to laboratory test conditions for nutrition research.

Subjective satiety and plasma PYY concentration after wholemeal pasta

Dietary fiber and whole grain foods may contribute to the regulation of appetite; however, evidence has produced inconclusive findings. The objective was to evaluate the effects of an experimental wholemeal pasta on appetite ratings, plasma concentrations of gastrointestinal hormones involved in appetite control, and postprandial glucose/insulin responses in healthy adults. Fourteen healthy adults (7M/7F), mean age 30±2 yrs (mean±SEM), participated in a randomized, controlled, crossover trial. Participants consumed on two different days, at one week interval, 117g of wholemeal pasta or 100g of refined wheat pasta (control pasta), similar in energy and macronutrient composition except for fiber amount, which was higher in wholemeal pasta (11 vs 3 g). Appetite ratings, glucose/insulin/lipid and gastrointestinal hormone responses were measured at fasting and for 4-h after the ingestion of the pasta tests, after which self-reported energy intake for 8-h was evaluated. After the wholemeal pasta, the desire to eat and the sensation of hunger were lower (-16%, p=0.04 and -23%, p=0.004, respectively) and satiety was higher (+13%; p=0.08) compared with the control pasta; no effect on self-reported energy intake at subsequent meal was observed. After wholemeal pasta, glucose, triglyceride increased and GLP-1 responses were not different compared to control pasta but insulin response at 30 min (p<0.05) and ghrelin at 60 min (p=0.03) were lower and PYY levels higher (AUC=+44%, p=0.001). The appetite rating changes correlated with PYY plasma levels (p<0.03). In conclusion, consumption of whole grain instead of refined wheat pasta contributed to appetite control but did not seem to influence acute energy balance. Appetite ratings were associated with modifications in PYY hormone concentrations.

The nutritional property of endosperm starch and its contribution to the health benefits of whole grain foods

Purported health benefits of whole grain foods in lowering risk of obesity, type 2 diabetes, cardiovascular disease, and cancer are supported by epidemiological studies and scientific researches. Bioactive components including dietary fibers, phytochemicals, and various micronutrients present in the bran and germ are commonly considered as the basis for such benefits. Endosperm starch, as the major constituent of whole grains providing glucose to the body, has been less investigated regarding its nutritional property and contribution to the value of whole grain foods. Nutritional quality of starch is associated with its rate of digestion and glucose absorption. In whole grain foods, starch digestion and glucose delivery may vary depending on the form in which the food is delivered, some with starch being rapidly and others slowly digested. Furthermore, there are other inherent factors in whole grain products, such as phenolic compounds and dietary fibers, that may moderate glycemic profiles. A good understanding of the nutritional properties of whole grain starch is important to the development of food processing technologies to maximize their health benefits.

The Cross-Sectional Association between Consumption of the Recommended Five Food Group "Grain (Cereal)", Dietary Fibre and Anthropometric Measures among Australian Adults

The Australian Dietary Guidelines recommended "grain (cereal)" core food group includes both refined and whole grain foods, but excludes those that are discretionary (i.e., cakes). We investigated the association between daily serves from the "grain (cereal)" group and its effect on fibre and adiposity. Data from Australian adults in the 2011-2012 National Nutrition and Physical Activity Survey were used (n = 9341). Participants were categorised by serves of core grain foods and general linear models were used to investigate the effect of demographic, socioeconomic, and dietary covariates on waist circumference, body mass index (BMI) and fibre intake. Compared to core grain avoiders (0 serves), high consumers (6+ serves/day) were: more likely male and socially advantaged, had a healthier dietary pattern, less likely dieting, overweight or obese, and were at lower risk of metabolic complications. After adjustment for age, sex and energy intake, there was an inverse relationship between core grain serves intake and BMI (p < 0.001), waist circumference (p = 0.001) and a positive relationship with fibre (p < 0.001). Model adjustments for diet and lifestyle factors resulted in a smaller difference in waist circumference (p = 0.006) and BMI (p = 0.006). Core grain serves was significantly associated with higher fibre, but marginally clinically significant for lower adiposity.

Association between barriers and facilitators to meeting the Dietary Guidelines for Americans and body weight status of caregiver-child dyads: the Healthy Eating and Lifestyle for Total Health Study

BACKGROUND

Few Americans meet the Dietary Guidelines for Americans (DGA), yet a large percentage are overweight.

OBJECTIVE

The goal of this research was to examine the association between barriers and facilitators to meeting the DGA and weight in a multisite study.

DESIGN

This was a cross-sectional study in which 836 caregiver-child dyads among 3 race/ethnic groups completed the questionnaire across 6 sites participating in the HEALTH (Healthy Eating and Lifestyle for Total Health) Study. Barriers and facilitators to meeting the DGA were assessed by using a validated questionnaire developed specifically for the HEALTH Study. Heights and weights were measured. A series of bivariate regression analyses were conducted to examine the association between caregiver body mass index (BMI) or child BMI z score and the barriers and facilitators to meeting the DGA, adjusting for appropriate covariates in the models. Path analysis was used to examine the relation of caregiver and child barriers and facilitators to their relative BMIs.

RESULTS

In children, the BMI z score was associated positively (P < 0.001) with total barriers and negatively (P < 0.001) with total facilitators. In caregivers, BMI was associated positively only with total barriers (P < 0.0001). For each of the 8 MyPyramid components, barriers consistently were associated positively (P < 0.0001) and facilitators were associated negatively (P < 0.001) with BMI z score in children (with the exception of the fruit and physical activity components). For caregivers, most of the barriers to meeting recommendations for meats and beans; solid fats, alcohol, and added sugars; and physical activity components were associated positively (P < 0.01) with BMI. Path analyses show that caregiver facilitators were significantly related to children's facilitators to meeting DGA recommendations (standardized β: 0.12; P < 0.001).

CONCLUSION

To our knowledge, our findings are among the first to show associations between weight and barriers and/or facilitators to meeting the DGA in a national, large sample of caregiver-child dyads. This trial was registered at clinicaltrials.gov as NCT02725970.

Whole grain consumption trends and associations with body weight measures in the United States: results from the cross sectional National Health and Nutrition Examination Survey 2001-2012

BACKGROUND

The purpose of this study was (1) to describe intakes of total grain and whole grain in the United States over the past 12 years and major dietary sources, and (2) to determine the relationship between whole grain intake and adiposity measures for children and adults.

METHODS

Cross-sectional dietary data from the continuous National Health and Nutrition Examination Survey 2001-12 (6 2-year cycles) for children 6-18 years (n = 15,280) and adults 19+ years (n = 29,683) were linked to the My Pyramid and Food Patterns Equivalents Databases to assess daily intake of total grain and whole grain. These populations were classified into groups based on average whole grain intake: 0 ounce equivalents (oz eq)/day, > 0 and <1 oz eq/day, and ≥1 oz eq/day. Within these classifications, body mass index, waist circumference, and percent overweight/obese were identified. Regression and logistic regression analyses were used to assess associations between these dependent variables and whole grain intake.

RESULTS

Adults consumed a mean 0.72 whole grain oz eq/day in 2001-02 and 0.97 oz eq/day in 2011-12 and children consumed a mean 0.56 whole grain oz eq/day in 2001-02 and 0.74 oz eq/day in 2011-12. While over 70 % of children and 60 % of adults met daily intake recommendations for total grain, less than 1.0 and 8.0 % percent of children and adults, respectively, met whole grain recommendations in 2011-12. Adults and children who consumed whole grain had significantly better intakes of nutrients and dietary fiber compared to non-consumers. From 2001 to 2012, grain mixed dishes and yeast breads were the leading sources of total grain, while yeast breads and ready to eat cereals were the leading sources of whole grain for both children and adults. Multiple regression analysis showed a significant, inverse relationship between body mass index and waist circumference with respect to whole grain intake after adjustment for covariates in both children and adults (p < 0.05). Similarly, logistic regression analysis showed a significant inverse relationship between percent overweight/obese and whole grain intake (p < 0.05).

CONCLUSIONS

Although most children and adults meet daily intake goals for grain foods overall, whole grain as a portion of total grain intake continues to be consumed at levels well below recommendations. The data from the current study suggest that greater whole grain consumption is associated with better intakes of nutrients and healthier body weight in children and adults. Continued efforts to promote increased intake of whole grain foods are warranted.

Relationship between bread and obesity

Some studies have indicated that promoting the Mediterranean diet pattern as a model of healthy eating may help to prevent weight gain and the development of overweight/obesity. Bread consumption, which has been part of the traditional Mediterranean diet, has continued to decline in Spain and in the rest of the world, because the opinion of the general public is that bread fattens. The present study was conducted to assess whether or not eating patterns that include bread are associated with obesity and excess abdominal adiposity, both in the population at large or in subjects undergoing obesity management. The results of the present review indicate that reducing white bread, but not whole-grain bread, consumption within a Mediterranean-style food pattern setting is associated with lower gains in weight and abdominal fat. It appears that the different composition between whole-grain bread and white bread varies in its effect on body weight and abdominal fat. However, the term ‘whole-grain bread’ needs to be defined for use in epidemiological studies. Finally, additional studies employing traditional ways of bread production should analyse this effect on body-weight and metabolic regulation.