Dairy and weight loss hypothesis: an evaluation of the clinical trials

Global prevalence of diet low in calcium and the disease burden: results from the Global Burden of Disease Study 2019

BACKGROUND

Due to the essential role of calcium in vital biological functions, diet low in calcium (DLC) is associated with various diseases. However, there is a lack of study about the current prevalence and health burden due to DLC using reliable data sources.

METHODS

We used data from the Global Burden of Disease study 2019 (GBD 2019) to estimate the prevalence and health burden of DLC in 204 countries from 1990 to 2019, by age, sex, and sociodemographic index (SDI). The estimates were produced in DisMod-MR 2.1, a Bayesian meta-regression tool. Summary exposure value (SEV) was used to show the prevalence of DLC, while diseases adjusted life year (DALY) was used to represent the disease burden. The disease burden was estimated for DLC-induced colorectal cancer. Spearman Rank Order correlation was used for correlation analysis, and estimated annual percentage (EAPC) was used to reflect the temporal trends.

RESULTS

From 1990 to 2019, the global prevalence of DLC decreased (EAPC of SEV, -0.47; 95% CI, -0.5 to -0.43), but have increased in Oceania region and in many countries, such as United Arab Emirates, New Zealand, Japan, and France. The global DALYs associated with low in calcium were estimated to be 3.14 million (95% uncertainty interval (UI), 2.25-4.26 million) in 2019, with an age standardized rate of 38.2 (95% UI, 27.2-51.8) per 100,000. Unlike the prevalence, the global age standardized DALY rates has remained unchanged (EAPC, -0.03; 95% CI, -0.12 to 0.07), but has increased in over 80 of the 204 countries, located mainly in Asia, Africa, and South America. In all years and regions, the age standardized SEV and DALY rates were higher in male people than that in female people. The prevalence (rho = -0.823; P < 0.001) and disease burden (rho = -0.433; P < 0.001) associated with diet in low calcium were strongly correlated to SDI. The prevalence decreased with age, but the DALY rates increased with age and peaked at about 90 years. The prevalence of DLC has decreased worldwide and in most countries, but the disease burden of DLC induced colorectal cancer has increased in over 40% of countries worldwide.

CONCLUSION

Countries with low sociodemographic level and male people are more likely to experience the risk of DLC and related disease burden. Related measures in improve dietary calcium intake are in need to address diet in low calcium related health problems.

An eight-week randomized intervention study on Korean adults to evaluate the effect of milk intake on obesity

The anti-obesity effect of milk intake has been suggested via a variety of designed studies, but findings of obesity interventions for Korean adults are scarcely reported. The study aimed to investigate the anti-obesity effect of cow milk in Korean adults with an 8-wk randomized intervention. A total of 121 adults overweight aged 19 to 60 yr old were randomly assigned to 1 of the 2 groups: milk or control. During the intervention, both groups were encouraged 500 kcal of restriction a day, and the milk group consumed 200 mL of milk twice a day; the same energy intake as the control group, including milk intake, was recommended for 8 wk. We detected no significant differences in body weight (BW) and body mass index (BMI) between the milk and control groups during the 8-wk intervention, although the changes in BW and BMI of those within the milk group were significant. High-density lipoprotein cholesterol levels and serum calcium levels increased significantly in the milk group compared with the control group. Calcium, phosphorus, vitamin A, and riboflavin intakes increased significantly, when compared with the control. In conclusion, 8-wk milk consumption had no effect on weight loss and BMI change but improved some blood biomarkers and nutrient intake in Korean adults who were overweight. To evaluate the effect of milk on obesity reduction, well-designed, long-term, and large-scale studies are needed.

Whole milk compared with reduced-fat milk and childhood overweight: a systematic review and meta-analysis

BACKGROUND

The majority of children in North America consume cow-milk daily. Children aged >2 y are recommended to consume reduced-fat (0.1-2%) cow-milk to lower the risk of obesity.

OBJECTIVES

To evaluate the relation between cow-milk fat consumption and adiposity in children aged 1-18 y.

METHODS

Embase (Excerpta Medica Database), CINAHL (Cumulative Index to Nursing and Allied Health Literature), MEDLINE, Scopus, and Cochrane Library databases from inception to August 2019 were used. The search included observational and interventional studies of healthy children aged 1-18 y that described the association between cow-milk fat consumption and adiposity. Two reviewers extracted data, using the Newcastle-Ottawa Scale to assess risk of bias. Meta-analysis was conducted using random effects to evaluate the relation between cow-milk fat and risk of overweight or obesity. Adiposity was assessed using BMI z-score (zBMI).

RESULTS

Of 5862 reports identified by the search, 28 met the inclusion criteria: 20 were cross-sectional and 8 were prospective cohort. No clinical trials were identified. In 18 studies, higher cow-milk fat consumption was associated with lower child adiposity, and 10 studies did not identify an association. Meta-analysis included 14 of the 28 studies (n = 20,897) that measured the proportion of children who consumed whole milk compared with reduced-fat milk and direct measures of overweight or obesity. Among children who consumed whole (3.25% fat) compared with reduced-fat (0.1-2%) milk, the OR of overweight or obesity was 0.61 (95% CI: 0.52, 0.72; P < 0.0001), but heterogeneity between studies was high (I2 = 73.8%).

CONCLUSIONS

Observational research suggests that higher cow-milk fat intake is associated with lower childhood adiposity. International guidelines that recommend reduced-fat milk for children might not lower the risk of childhood obesity. Randomized trials are needed to determine which cow-milk fat minimizes risk of excess adiposity. This systematic review and meta-analysis was registered with PROSPERO (registration number: CRD42018085075).

Role of Calcium and Low-Fat Dairy Foods in Weight-Loss Outcomes Revisited: Results from the Randomized Trial of Effects on Bone and Body Composition in Overweight/Obese Postmenopausal Women

Several studies have investigated the possibility of dairy foods and calcium (Ca) mediating weight and body composition, but a consensus has not been reached. We aimed to investigate weight-loss-related outcomes during intervention with low-fat dairy foods or Ca + vitamin D supplements, both as complements to hypocaloric diets. Overweight/obese Caucasian, early-postmenopausal women (n = 135) were recruited for a 6 month energy-restricted weight loss study complemented with either low-fat dairy foods (D; 4–5 servings/day), or Ca + vitamin D supplements (S); both to amount a total of ~1500 mg/day and 600 IU/day of Ca and vitamin D, respectively, or placebo pills (C). Bone mineral density (BMD) and lean and fat tissue were measured by Lunar iDXA. Serum and urinary markers of bone turnover were analyzed. Diet and physical activity were assessed with 3-day records. Participants on average lost ~4%, ~3%, and ~2% of body weight, fat, and lean tissue, respectively. The significantly better outcomes were noticed in participants in the D group regarding body composition (fat loss/lean tissue preservation) and in participants in the S group regarding the BMD outcomes, compared to those in the C group. Therefore, increasing low-fat dairy foods to 4–5 servings/day and/or increasing Ca & vitamin D intake by supplements (in those who are at the borderline dietary intake) may be beneficial for weight loss/maintenance and may lead to more favorable bone and body composition outcomes in postmenopausal women during moderate weight loss.

Effects of Dairy Consumption on Body Composition and Bone Properties in Youth: A Systematic Review

Background: According to previous reviews, there is no clear evidence on the effects of dairy consumption on body composition and bone properties in pediatric populations. There is a need for further assessment of existing findings and the methodologic quality of studies before summarizing the evidence. Objective: The aim of the study was to assess the quality, methodologies, and substantive findings of randomized controlled trials (RCTs) that examined the effects of dairy consumption on body size, body composition, and bone properties in children and adolescents. Methods: After searching PubMed and Google Scholar up to December 2016, 15 RCTs were retained and included in this systematic review for further analysis. The quality of the included studies was assessed via the Jadad scale; detailed methodologic and statistical characteristics were evaluated, and the main findings were summarized. Results: The effects of dairy consumption were found to be significant for bone structure and nonsignificant for body size and composition. Eight of the 11 RCTs that assessed bone found significant effects (P < 0.05) for bone mineral content and bone mineral density (BMD), with an average 8% increase in BMD after 16 mo of dairy consumption. Conversely, significant effects (P < 0.05) were found only in 2 of the 14 RCTs that focused on body size (i.e., height and weight) and in only 1 of the 11 RCTs that focused on body composition (i.e., lean mass). Conclusions: The systematic consumption of dairy products may benefit bone structure and development, but it does not appear to affect body composition or body size in children and adolescents. On the basis of the Jadad scale, the methodologic quality of the 15 RCTs was rated as good overall. However, there were methodologic disparities and limitations that may have led to nonsignificant results, particularly for body size and composition. Future RCTs designed to address these limitations are warranted.

The Consumption of Dairy Products Is Associated with Reduced Risks of Obesity and Metabolic Syndrome in Korean Women but not in Men

We aimed to investigate the association between dairy product consumption and the risk of obesity and metabolic syndrome (MetS) in Korean adults. Data from 13,692 Korean adults aged ≥19 years from the KNHANES 2010–2013 were used. The study participants were divided into three groups according to the serving size of dairy products they consumed based on a single 24-h recall. About 58% of the Korean adults did not consume any dairy products in one day. In both the sexes, only those who adhered to the recommendation for dairy products (≥1 serving/day) achieved the daily requirement of calcium. Women who consumed ≥1 serving/day of dairy products had lower risks of obesity (body mass index ≥ 25 kg/m²) (adjusted odds ratio (AOR), 0.77; 95% confidence interval (CI), 0.66–0.89; p for trend < 0.01) and MetS (AOR, 0.67; 95% CI, 0.56–0.80; p for trend < 0.01) than women who did not consume dairy products. However, these significant associations were not observed in men. In conclusion, consuming ≥ 1 serving/day of dairy products could be an easy and efficient strategy for meeting daily calcium requirement as well as lowering risks of obesity and MetS among Korean women.

The effect of increasing dairy calcium intake of adolescent girls on changes in body fat and weight

Background: Overweight is epidemic in adolescents and is a major concern because it tracks into adulthood. Evidence supports the efficacy of high-calcium, high-dairy diets in achieving healthy weight in adults. However, no randomized controlled trials of the effect of dairy food on weight and body fat in adolescents have been reported to our knowledge.Objective: The aim was to determine whether increasing calcium intake to recommended amounts with dairy foods in adolescent girls with habitually low calcium intakes would decrease body fat gain compared with girls who continued their low calcium intake. Participants had above-the-median body mass index (BMI; in kg/m²).Design: We enrolled 274 healthy postmenarcheal 13- to 14-y-old overweight girls who had calcium intakes of ≤600 mg/d in a 12-mo randomized controlled trial. Girls were randomly assigned in a 1:1 ratio to 1 of 2 groups within each of 3 BMI percentiles: 50th to <70th, 70th to <85th, and 85th to <98th. The assignments were 1) dairy, which included low-fat milk or yogurt servings providing ≥1200 mg Ca/d or 2) control, which included the usual diet of ≤600 mg Ca/d.Results: We failed to detect a statistically significant difference between groups in percentage of body fat gain over 12 mo (mean ± SEM: dairy 0.40% ± 0.53% > control; P < 0.45). The effect of the intervention did not differ by BMI percentile stratum. There was no difference in weight change between the 2 groups.Conclusion: Our findings that the dairy group gained body fat similar to the control group provide no support for dairy food as a stratagem to decrease body fat or weight gain in overweight adolescent girls. This trial was registered at clinicaltrials.gov as NCT01066806.

Yogurt consumption and abdominal obesity reversion in the PREDIMED study

BACKGROUND AND AIMS

Evidence on the association yogurt consumption and obesity is not conclusive. The aim of this study was to prospectively evaluate the association between yogurt consumption, reversion of abdominal obesity status and waist circumference change in elderly.

METHODS AND RESULTS

4545 individuals at high cardiovascular risk were prospectively followed. Total, whole-fat and low-fat yogurt consumption were assessed using food frequency questionnaires. Generalized estimating equations were used to analyze the association between yogurt consumption and waist circumference change (measured at baseline and yearly during the follow-up). Logistic regression models were used to evaluate the odds ratios (ORs) and 95% CIs of the reversion rate of abdominal obesity for each quintile of yogurt consumption compared with the lowest quintile. After multivariable adjustment, the average yearly waist circumference change in the quintiles of whole-fat yogurt consumption was: Q1: 0.00, Q2: 0.00 (-0.23 to 0.23), Q3: -0.15 (-0.42 to 0.13), Q4: 0.10 (-0.21 to 0.42), and Q5: -0.23 (-0.46 to -0.00) cm; p for trend = 0.05. The ORs for the reversion of abdominal obesity for whole-fat yogurt consumption were Q1: 1.00, Q2: 1.40 (1.04-1.90), Q3: 1.33 (0.94-1.89), Q4: 1.21 (0.83-1.77), and Q5: 1.43 (1.06-1.93); p for trend = 0.26.

CONCLUSION

Total yogurt consumption was not significantly associated with reversion of abdominal obesity status and a lower waist circumference. However, consumption of whole-fat yogurt was associated with changes in waist circumference and higher probability for reversion of abdominal obesity. Therefore, it seems that whole-fat yogurt has more beneficial effects in management of abdominal obesity in elderly population at high cardiovascular risk.

Calcium intake: good for the bones but bad for the heart? An analysis of clinical studies

The proper dietary calcium intake and calcium supplementation, when indicated, are important factors in the acquisition of peak bone mass during youth and in the prevention of fractures in old age. In addition to its deposition in bone, calcium confers an increase in its resistance and exhibits important activities in different enzymatic pathways in the body (e.g., neural, hormonal, muscle-related and blood clotting pathways). Thus, calcium supplementation can directly or indirectly affect important functions in the body, such as the control of blood pressure, plasma glucose, body weight, lipid profile and endothelial function. Since one publication reported increased cardiovascular risk due to calcium supplementation, many researchers have studied whether this risk actually exists; the results are conflicting, and the involved mechanisms are uncertain. However, studies that have evaluated the influence of the consumption of foods rich in calcium have reported no increase in the cardiovascular risk, which suggests that nutritional intake should be prioritized as a method for supplementation and that the use of calcium supplements should be reserved for patients who truly need supplementation and are unable to achieve the recommended daily nutritional intake of calcium.

Metabolic Effects of a 24-Week Energy-Restricted Intervention Combined with Low or High Dairy Intake in Overweight Women: An NMR-Based Metabolomics Investigation

We investigated the effect of a 24-week energy-restricted intervention with low or high dairy intake (LD or HD) on the metabolic profiles of urine, blood and feces in overweight/obese women by NMR spectroscopy combined with ANOVA-simultaneous component analysis (ASCA). A significant effect of dairy intake was found on the urine metabolome. HD intake increased urinary citrate, creatinine and urea excretion, and decreased urinary excretion of trimethylamine-N-oxide (TMAO) and hippurate relative to the LD intake, suggesting that HD intake was associated with alterations in protein catabolism, energy metabolism and gut microbial activity. In addition, a significant time effect on the blood metabolome was attributed to a decrease in blood lipid and lipoprotein levels due to the energy restriction. For the fecal metabolome, a trend for a diet effect was found and a series of metabolites, such as acetate, butyrate, propionate, malonate, cholesterol and glycerol tended to be affected. Overall, even though these effects were not accompanied by a higher weight loss, the present metabolomics data reveal that a high dairy intake is associated with endogenous metabolic effects and effects on gut microbial activity that potentially impact body weight regulation and health. Moreover, ASCA has a great potential for exploring the effect of intervention factors and identifying altered metabolites in a multi-factorial metabolomic study.

Effects of Dairy Products Consumption on Health: Benefits and Beliefs--A Commentary from the Belgian Bone Club and the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases

Dairy products provide a package of essential nutrients that is difficult to obtain in low-dairy or dairy-free diets, and for many people it is not possible to achieve recommended daily calcium intakes with a dairy-free diet. Despite the established benefits for bone health, some people avoid dairy in their diet due to beliefs that dairy may be detrimental to health, especially in those with weight management issues, lactose intolerance, osteoarthritis, rheumatoid arthritis, or trying to avoid cardiovascular disease. This review provides information for health professionals to enable them to help their patients make informed decisions about consuming dairy products as part of a balanced diet. There may be a weak association between dairy consumption and a possible small weight reduction, with decreases in fat mass and waist circumference and increases in lean body mass. Lactose intolerant individuals may not need to completely eliminate dairy products from their diet, as both yogurt and hard cheese are well tolerated. Among people with arthritis, there is no evidence for a benefit to avoid dairy consumption. Dairy products do not increase the risk of cardiovascular disease, particularly if low fat. Intake of up to three servings of dairy products per day appears to be safe and may confer a favourable benefit with regard to bone health.

Consumption of Yogurt, Low-Fat Milk, and Other Low-Fat Dairy Products Is Associated with Lower Risk of Metabolic Syndrome Incidence in an Elderly Mediterranean Population

BACKGROUND

The association between consumption of dairy products and the risk of developing metabolic syndrome (MetS) is unclear.

OBJECTIVE

The purpose of this study was to evaluate the associations between consumption of dairy products (total and different subtypes) and incident MetS in a Mediterranean population at high cardiovascular disease risk.

METHODS

We prospectively analyzed 1868 men and women (55-80 y old) without MetS at baseline, recruited from different PREDIMED (Prevención con Dieta Mediterránea) centers between October 2003 and June 2009 and followed up until December 2010. MetS was defined according to updated, harmonized criteria. At baseline and yearly thereafter, we determined anthropometric variables, dietary habits by a 137-item validated food-frequency questionnaire, and blood biochemistry. Multivariable-adjusted HRs of MetS or its components were estimated for each of the 2 upper tertiles (vs. the lowest one) of mean consumption of dairy products during the follow-up.

RESULTS

During a median follow-up of 3.2 y, we documented 930 incident MetS cases. In the multivariable-adjusted model, HRs (95% CIs) of MetS for the comparison of extreme tertiles of dairy product consumption were 0.72 (0.61, 0.86) for low-fat dairy, 0.73 (0.62, 0.86) for low-fat yogurt, 0.78 (0.66, 0.92) for whole-fat yogurt, and 0.80 (0.67, 0.95) for low-fat milk. The respective HR for cheese was 1.31 (1.10, 1.56).

CONCLUSIONS

Higher consumption of low-fat dairy products, yogurt (total, low-fat, and whole-fat yogurt) and low-fat milk was associated with a reduced risk of MetS in individuals at high cardiovascular disease risk from a Mediterranean population. Conversely, higher consumption of cheese was related to a higher risk of MetS. This trial was registered at controlled-trials.com as ISRCTN35739639.

The effects of a calcium-rich pre-exercise meal on biomarkers of calcium homeostasis in competitive female cyclists: a randomised crossover trial

Cycling is recognised as a sport in which there is a high incidence of poor bone health. Sweat calcium losses may contribute to this.

Dietary Patterns as Predictors of Body Fat and BMI in Women: A Factor Analytic Study

Purpose.

To identify independent patterns of diet using factor analysis to determine the extent to which dietary patterns account for differences in body fat percentage (BF%) and body mass index (BMI). Also, to ascertain the extent to which the associations are influenced by age, education, menopause, energy intake, and physical activity.

Design.

Study design was cross-sectional.

Setting.

Study setting was approximately 20 cities in the Mountain West.

Subjects.

The study included 281 apparently healthy female nonsmokers.

Measures.

Diet was assessed using 7-day weighed food records, and foods were categorized using the American Diabetes and American Dietetic Associations Exchange Lists and expressed as servings per 1000 kcal. BF% was measured using the Bod Pod, and physical activity was estimated using accelerometers worn for 1 week.

Analysis.

We used factor analysis, general linear models, and partial correlations.

Results.

Three dietary patterns were identified: (1) Prudent Pattern, (2) Low-fat Milk, and (3) Meat. Higher consumption of the Prudent Pattern corresponded with significantly lower BF% (F = 8.5, p = .0038) and BMI (F = 4.4, p = .0363). The Low-fat Milk pattern was inversely related to BF% (F= 5.4, p = .0207) and BMI (F= 9.5, p = .0023). Higher intake of the Meat pattern was related to higher levels of BF% (F= 4.5, p= .0346) and BMI (F= 4.2, p = .0418).

Conclusion.

These findings support an association between dietary patterns and body composition. Dietary patterns reflect the complex interrelationships inherent in day-to-day eating and are strongly related to differences in BF% and BMI in women.

New reference values for calcium

The nutrition societies of Germany, Austria and Switzerland are the joint editors of the 'reference values for nutrient intake'. They have revised the reference values for the intake of calcium and published them in June 2013. The reference values for the calcium intake for infants are derived from the calcium content of breast milk. For infants from 4 to <12 months of age, the calcium intake from solid foods is included in addition to the calcium intake from breast milk. Thus, the reference values for infants are estimated values; they are 220 mg/day for infants to <4 months and 330 mg/day for infants from 4 to <12 months of age. As a parameter for determining the calcium requirement in children and adolescents, calcium retention is taken into account. The average requirement is calculated by the factorial method. A balanced calcium metabolism is calculated based upon calcium balance studies and used as a parameter for the determination of the calcium requirement in adults. On the basis of the average requirement, recommended calcium intake levels for children, adolescents and adults are derived. Depending on age, the recommended calcium intake ranges between 600 mg/day for children aged 1 to <4 years and 1,200 mg/day for adolescents aged 13 to <19 years; for adults, it is 1,000 mg/day.

Changes in both global diet quality and physical activity level synergistically reduce visceral adiposity in men with features of metabolic syndrome

With regard to the beneficial impact of lifestyle interventions on weight and abdominal obesity management, our objective was to identify which components of a lifestyle-intervention program [physical activity (PA), energy and macronutrient intake, diet quality] had an influence on visceral adipose tissue (VAT) loss. The present lifestyle intervention targeted a daily energy deficit (500 kcal), coupled with a PA program (160 min/wk). From the 144 participants initially recruited, 93 viscerally obese men (age: 49 ± 1 y; waist circumference: 108 ± 9 cm; plasma triglyceride concentration: 2.46 ± 0.09 mmol/L) who completed a 3-d dietary journal both at baseline and after 1 y of intervention and a daily PA journal for 1 y were considered in the present analyses. Body composition and fat distribution were assessed by using dual-energy X-ray absorptiometry and computed tomography. After 1 y, abdominally obese men significantly improved their diet quality, as assessed by the Dietary Approaches to Stop Hypertension (DASH)-derived diet quality (DQ) score (P < 0.0001). Improved DQ and higher levels of PA were both independently and significantly associated with reductions in body weight, fat mass, VAT, and thigh muscle fat content, beyond reported energy intake or diet macronutrient composition. When stratified according to the level of PA and DQ [PA- (low PA), DQ- (low DQ), PA+ (high PA), DQ+ (high DQ)], the PA+/DQ+ group showed reductions in VAT that were 20% greater than in the PA-/DQ+ group, 28% greater than in the PA+/DQ- group, and 50% (P < 0.05) greater than in the PA-/DQ- group. Our results highlight the strong contribution of DQ beyond macronutrient and energy content to changes in body composition and suggest that synergistic changes in both DQ and PA levels optimally reduce VAT in men with features of metabolic syndrome.

Longitudinal association between dairy consumption and changes of body weight and waist circumference: the Framingham Heart Study

Background

Dairy foods are nutrient-dense and may be protective against long-term weight gain.

Objective

We aimed to examine the longitudinal association between dairy consumption and annualized changes in weight and waist circumference (WC) in adults.

Methods

Members of the Framingham Heart Study Offspring Cohort who participated in the 5^th through 8^th study examinations (1991–2008) were included in these analyses (3,440 participants with 11,683 observations). At each exam, dietary intake was assessed by a validated food frequency questionnaire, and weight and WC were assessed following standardized procedures. Repeated measures models were used for the longitudinal analyses by adjusting for time-varying or invariant covariates.

Results

On average, participants gained weight and WC during follow-up. Dairy intake increased across exams. After adjusting for demographic and lifestyle factors (including diet quality), participants who consumed ≥3 servings/d of total dairy had 0.10 [±0.04] kg smaller annualized increment of weight (P_trend=0.04) than those consuming <1 serving/d. Higher total dairy intake was also marginally associated with less WC gain (P_trend=0.05). Similarly, participants who consumed ≥3 servings/wk of yogurt had a 0.10 [±0.04] kg and 0.13 [±0.05] cm smaller annualized increment of weight (P_trend=0.03) and WC (P_trend=0.008) than those consuming <1 serving/wk, respectively. Skim/low-fat milk, cheese, total high-fat or total low-fat dairy intake was not associated with long-term change of weight or WC.

Conclusion

Further longitudinal and interventional studies are warranted to confirm the beneficial role of increasing total dairy and yogurt intake, as part of a healthy and calorie-balanced dietary pattern, in the long-term prevention of gain in weight and WC.

The lactase persistence -13910C>T polymorphism shows indication of association with abdominal obesity among Portuguese children

AIM

The -13910C>T single nucleotide polymorphism located upstream of the lactase gene (LCT) was found tightly associated with lactase persistence in European populations. Recently, it was also associated with body mass index (BMI) and obesity in European adults. The aim of this study was to test the association of -13910C>T polymorphism with obesity-related traits and risk of obesity in children.

METHODS

We genotyped 580 Portuguese children (6-12-year-olds) for the -13910C>T polymorphism using TaqMan probes by real-time PCR. Anthropometric measurements were assessed in all children. Obesity was defined according to the International Obesity Task Force (IOTF) cut-offs and abdominal obesity using the sex and age-specific ≥90th waist circumference percentile.

RESULTS

We found indication for an association between the-13910*T allele and children abdominal obesity (odds ratio [OR] = 1.41; 95% confidence intervals [CI]: 1.03-1.94; p = 0.030). Under the dominant model, the indicative association was observed between the LCT-13910 CT/TT genotypes and abdominal obesity, remaining significant after adjustment for age and gender (OR = 1.65; 95% CI: 1.04-2.60; p = 0.029). No association was detected with the risk of obesity (p = 0.350).

CONCLUSION

Our results suggest that the -13910C>T polymorphism may predispose to abdominal obesity in Portuguese children. The association with BMI or risk of obesity, previously observed in adults, was not confirmed.

A dairy-based high calcium diet improves glucose homeostasis and reduces steatosis in the context of preexisting obesity

OBJECTIVE

High dietary calcium (Ca) in the context of a dairy food matrix has been shown to reduce obesity development and associated inflammation in diet-induced obese (DIO) rodents. The influence of Ca and dairy on these phenotypes in the context of preexisting obesity is not known. Furthermore, interpretations have been confounded historically by differences in body weight gain among DIO animals fed dairy-based protein or high Ca.

DESIGN AND METHODS

Adiposity along with associated metabolic and inflammatory outcomes were measured in DIO mice previously fattened for 12 week on a soy protein-based obesogenic high fat diet (45% energy, 0.5% adequate Ca), then fed one of three high fat diets (n = 29-30/group) for an additional 8 week: control (same as lead-in diet), high-Ca (1.5% Ca), or high-Ca + nonfat dry milk (NFDM).

RESULTS AND CONCLUSION

Mice fed high-Ca + NFDM had modestly, but significantly, attenuated weight gain compared to mice fed high-Ca or versus controls (P < 0.001), whereas mice fed high-Ca alone had increased weight gain compared to controls (P < 0.001). Total measured adipose depot weights between groups were similar, as were white adipose tissue inflammation and macrophage infiltration markers (e.g. TNFα, IL-6, CD68 mRNAs). Mice fed high-Ca + NFDM had significantly improved glucose tolerance following a glucose tolerance test, and markedly lower liver triglycerides compared to high-Ca and control groups. Improved metabolic phenotypes in prefattened DIO mice following provision of a diet enriched with dairy-based protein and carbohydrates appeared to be driven by non-Ca components of dairy and were observed despite minimal differences in body weight or adiposity.

Dietary strategies to increase satiety

Obesity has a multifactorial etiology. Although obesity is widespread and associated with serious health hazards, its effective prevention and treatment have been challenging. Among the currently available treatment approaches, lifestyle modification to induce a negative energy balance holds a particularly larger appeal due to its wider reach and relative safety. However, long-term compliance with dietary modifications to reduce energy intake is not effective for the majority. The role of many individual nutrients, foods, and food groups in inducing satiety has been extensively studied. Based on this evidence, we have developed sample weight-loss meal plans that include multiple satiating foods, which may collectively augment the satiating properties of a meal. Compared to a typical American diet, these meal plans are considerably lower in energy density and probably more satiating. A diet that exploits the satiating properties of multiple foods may help increase long-term dietary compliance and consequentially enhance weight loss.

Dairy product consumption, calcium intakes, and metabolic syndrome-related factors over 5 years in the STANISLAS study

OBJECTIVE

We assessed the associations of total dairy products; milk, yogurt, and cottage cheese; cheese; and calcium with 5-y changes in components of the metabolic syndrome.

METHODS

Two hundred eighty-eight men and 300 women 28 to 60 y of age from the suivi temporaire annuel non invasif de la santé des lorrains assurés sociaux (STANISLAS) cohort completed at baseline a 3-d dietary record. Statistics were performed using multivariate regression analysis.

RESULTS

In men, no relation was found between the four dietary indices and components of the metabolic syndrome measured at baseline. Conversely, the consumption of milk, yogurt, and cottage cheese at entry was inversely associated with 5-y changes in glucose levels (P ≤ 0.05, P ≤ 0.01 for sex interaction) and positively with 5-y changes in high-density lipoprotein cholesterol (P ≤ 0.05). Higher calcium intakes were significantly related to a lower 5-y increase of the body mass index (BMI) and waist circumference in men (P ≤ 0.01, P ≤ 0.05 for sex interaction). In addition, changes in diastolic blood pressure were inversely associated with the consumption of milk, yogurt, and cottage cheese only in men with a normal BMI (P ≤ 0.05 for BMI interaction). In women, unlike men, associations were shown for some components measured at baseline: total dairy positively related to BMI and waist circumference; total dairy, milk, yogurt, and cottage cheese, and calcium were positively related to triacylglycerols and negatively to high-density lipoprotein cholesterol. However, no significant association was found for any 5-y-changes.

CONCLUSION

In men only, a higher consumption of dairy products was associated with positive changes in the metabolic profile in a 5-y period; a higher calcium consumption was associated with a lower 5-y increase of the BMI and waist circumference.

Skim milk, whey, and casein increase body weight and whey and casein increase the plasma C-peptide concentration in overweight adolescents

In adults, dietary protein seems to induce weight loss and dairy proteins may be insulinotropic. However, the effect of milk proteins in adolescents is unclear. The objective was to test whether milk and milk proteins reduce body weight, waist circumference, homeostatic model assessment, plasma insulin, and insulin secretion estimated as the plasma C-peptide concentration in overweight adolescents. Overweight adolescents (n = 203) aged 12-15 y with a BMI of 25.4 ± 2.3 kg/m(2) (mean ± SD) were randomized to 1 L/d of skim milk, whey, casein, or water for 12 wk. All milk drinks contained 35 g protein/L. Before randomization, a subgroup of adolescents (n = 32) was studied for 12 wk before the intervention began as a pretest control group. The effects of the milk-based test drinks were compared with baseline (wk 0), the water group, and the pretest control group. Diet and physical activity were registered. Outcomes were BMI-for-age Z-scores (BAZs), waist circumference, plasma insulin, homeostatic model assessment, and plasma C-peptide. We found no change in BAZ in the pretest control and water groups, whereas it was greater at 12 wk in the skim milk, whey, and casein groups compared with baseline and with the water and pretest control groups. The plasma C-peptide concentration increased from baseline to wk 12 in the whey and casein groups and increments were greater than in the pretest control (P < 0.02). There were no significant changes in plasma C-peptide in the skim milk or water group. These data suggest that high intakes of skim milk, whey, and casein increase BAZs in overweight adolescents and that whey and casein increase insulin secretion. Whether the effect on body weight is primary or secondary to the increased insulin secretion remains to be elucidated.

Dairy consumption and cardiometabolic health: outcomes of a 12-month crossover trial

Background

A growing body of research suggests that regular consumption of dairy foods may counteract obesity and other components of the metabolic syndrome. However, human intervention trials are lacking. We aimed to determine the cardiometabolic health effects of increasing the consumption of reduced fat dairy foods in adults with habitually low dairy intakes in the absence of energy restriction.

Methods

An intervention trial was undertaken in 61 overweight or obese adults who were randomly assigned to a high dairy diet (HD, 4 serves of reduced fat dairy/day) or a low dairy control diet (LD, ≤1 serve/day) for 6 months then crossed over to the alternate diet for a further 6 months. A range of anthropometric and cardiometabolic parameters including body composition, metabolic rate, blood lipids, blood pressure and arterial compliance were assessed at the end of each diet phase.

Results

Total energy intake was 1120 kJ/day higher during the HD phase, resulting in slight weight gain during this period. However, there were no significant differences between HD and LD in absolute measures of waist circumference, body weight, fat mass or any other cardiometabolic parameter.

Conclusion

Recommended intakes of reduced fat dairy products may be incorporated into the diet of overweight adults without adversely affecting markers of cardiometabolic health.

Trial Registration

The trial was registered with the Australia and New Zealand Clinical Trials Registry (ACTRN12608000538347) on 24th October, 2008.

Extraskeletal benefits and risks of calcium, vitamin D and anti-osteoporosis medications

Drugs used for the prevention and the treatment of osteoporosis exert various favourable and unfavourable extra-skeletal effects whose importance is increasingly recognized notably for treatment selection.

INTRODUCTION

The therapeutic armamentarium for the prevention and the treatment of osteoporosis is increasingly large, and possible extra-skeletal effects of available drugs could influence the choice of a particular compound.

METHODS

The present document is the result of a national consensus, based on a systematic and critical review of the literature.

RESULTS

Observational research has suggested an inverse relationship between calcium intake and cardiovascular diseases, notably through an effect on blood pressure, but recent data suggest a possible deleterious effect of calcium supplements on cardiovascular risk. Many diverse studies have implicated vitamin D in the pathogenesis of clinically important non-skeletal functions or diseases, especially muscle function, cardiovascular disease, autoimmune diseases and common cancers. The possible effects of oral or intravenous bisphosphonates are well-known. They have been associated with an increased risk of oesophageal cancer or atrial fibrillation, but large-scale studies have not found any association with bisphosphonate use. Selective oestrogen receptor modulators have demonstrated favourable or unfavourable extra-skeletal effects that vary between compounds. Strontium ranelate has a limited number of non-skeletal effects. A reported increase in the risk of venous thromboembolism is not found in observational studies, and very rare cases of cutaneous hypersensitivity reactions have been reported. Denosumab has been introduced recently, and its extra-skeletal effects still have to be assessed.

CONCLUSION

Several non-skeletal effects of bone drugs are well demonstrated and influence treatment choices.

A high calcium diet containing nonfat dry milk reduces weight gain and associated adipose tissue inflammation in diet-induced obese mice when compared to high calcium alone

BACKGROUND

High dietary calcium (Ca) is reported to have anti-obesity and anti-inflammatory properties. Evidence for these properties of dietary Ca in animal models of polygenic obesity have been confounded by the inclusion of dairy food components in experimental diets; thus, effect of Ca per se could not be deciphered. Furthermore, potential anti-inflammatory actions of Ca in vivo could not be dissociated from reduced adiposity.

METHODS

We characterized adiposity along with metabolic and inflammatory phenotypes in diet-induced obese (DIO) mice fed 1 of 3 high fat diets (45% energy) for 12 wk: control (n = 29), high-Ca (n = 30), or high-Ca + nonfat dry milk (NFDM) (n = 30).

RESULTS

Mice fed high-Ca + NFDM had reduced body weight and adiposity compared to high-Ca mice (P < 0.001). Surprisingly, the high-Ca mice had increased adiposity compared to lower-Ca controls (P < 0.001). Hyperphagia and increased feed efficiency contributed to obesity development in high-Ca mice, in contrast to NFDM mice that displayed significantly reduced weight gain despite higher energy intake compared to controls (P < 0.001). mRNA markers of macrophages (e.g., CD68, CD11d) strongly correlated with body weight in all diet treatment groups, and most treatment differences in WAT inflammatory factor mRNA abundances were lost when controlling for body weight gain as a covariate.

CONCLUSIONS

The results indicate that high dietary Ca is not sufficient to dampen obesity-related phenotypes in DIO mice, and in fact exacerbates weight gain and hyperphagia. The data further suggest that putative anti-obesity properties of dairy emanate from food components beyond Ca.

Dietary intakes associated with successful weight loss and maintenance during the Weight Loss Maintenance trial

BACKGROUND

Dietary components effective in weight maintenance efforts have not been adequately identified.

OBJECTIVE

To determine the effects of changes in dietary consumption on weight loss and maintenance during the Weight Loss Maintenance clinical trial.

DESIGN

Weight Loss Maintenance was a randomized controlled trial. Successful weight loss participants who completed Phase I of the trial and lost 4 kg were randomized to one of three maintenance intervention arms in Phase II and followed for an additional 30 months.

PARTICIPANTS/SETTING

The multicenter trial was conducted from 2003 through 2007. This substudy included 828 successful weight loss participants.

METHODS

The Block Food Frequency Questionnaire (FFQ) was used to assess nutrient intake levels and food group servings. Carbohydrates, proteins, fats, dietary fiber, fruit/vegetable, and dairy servings were utilized as predictor variables. The FFQ was collected on all participants at study entry (beginning of Phase I). Those randomized to Phase II completed the FFQ at three additional time points: randomization (beginning of Phase II), 12 months, and 30 months.

INTERVENTION

The main intervention focused on long-term maintenance of weight loss using the Dietary Approaches to Hypertension diet. This substudy examined if changes to specific dietary variables were associated with weight loss and maintenance.

STATISTICAL ANALYSES PERFORMED

Linear regression models that adjusted for change in total energy examined the relationship between changes in dietary intake and weight for each time period. Site, age, race, sex, and a race-sex interaction were included as covariates.

RESULTS

Participants who substituted protein for fat lost, on average, 0.33 kg per 6 months during Phase I (P<0.0001) and 0.07 kg per 6 months during Phase II (P<0.0001) per 1% increase in protein. Increased intake of fruits and vegetables was associated with weight loss in Phases I and II: 0.29 kg per 6 months (P<0.0001) and 0.04 kg per 6 months (P=0.0062), respectively, per 1-serving increase. Substitution of carbohydrates for fat and protein for carbohydrates were associated with weight loss during both phases. Increasing dairy intake was associated with significant weight loss during Phase II (-0.17 kg per 6 months per 1-serving increase, P=0.0002), but not during Phase I. Dietary fiber revealed no significant findings.

CONCLUSIONS

Increasing fruits, vegetables, and low-fat dairy may help achieve weight loss and maintenance.

Dairy consumption and overweight and obesity: a systematic review of prospective cohort studies

A comprehensive literature search was undertaken to examine the relationship between dairy consumption and overweight/obesity in prospective cohort studies. A literature search from 1980 through to April 2010 was conducted. Nineteen cohort studies met all the inclusion criteria and were included in the systematic review. Of the 19 cohort studies, 10 were among children and adolescents (aged 2 to 14 years, n = 53 to 12,829, follow-up 8 months to 10 years) and nine among adults (aged 18 to 75 years, n = 248 to 42,696, follow-up 2 years to 12 years). A range of dairy food exposure measures were used. Eight studies (three out of 10 studies involving children and five out of nine studies involving adults) showed a protective association against increasing weight gain (measured in various ways); one reported a significant protective association only among men who were initially overweight; seven reported no effect; one reported an increased risk (among children), and two reported both a decreased and increased risk, depending on the dairy food type. The evidence from prospective cohort studies for a protective effect of dairy consumption on risk of overweight and obesity is suggestive but not consistent, making firm conclusions difficult.

Changes in diet and lifestyle and long-term weight gain in women and men

BACKGROUND

Specific dietary and other lifestyle behaviors may affect the success of the straightforward-sounding strategy "eat less and exercise more" for preventing long-term weight gain.

METHODS

We performed prospective investigations involving three separate cohorts that included 120,877 U.S. women and men who were free of chronic diseases and not obese at baseline, with follow-up periods from 1986 to 2006, 1991 to 2003, and 1986 to 2006. The relationships between changes in lifestyle factors and weight change were evaluated at 4-year intervals, with multivariable adjustments made for age, baseline body-mass index for each period, and all lifestyle factors simultaneously. Cohort-specific and sex-specific results were similar and were pooled with the use of an inverse-variance-weighted meta-analysis.

RESULTS

Within each 4-year period, participants gained an average of 3.35 lb (5th to 95th percentile, -4.1 to 12.4). On the basis of increased daily servings of individual dietary components, 4-year weight change was most strongly associated with the intake of potato chips (1.69 lb), potatoes (1.28 lb), sugar-sweetened beverages (1.00 lb), unprocessed red meats (0.95 lb), and processed meats (0.93 lb) and was inversely associated with the intake of vegetables (-0.22 lb), whole grains (-0.37 lb), fruits (-0.49 lb), nuts (-0.57 lb), and yogurt (-0.82 lb) (P≤0.005 for each comparison). Aggregate dietary changes were associated with substantial differences in weight change (3.93 lb across quintiles of dietary change). Other lifestyle factors were also independently associated with weight change (P<0.001), including physical activity (-1.76 lb across quintiles); alcohol use (0.41 lb per drink per day), smoking (new quitters, 5.17 lb; former smokers, 0.14 lb), sleep (more weight gain with <6 or >8 hours of sleep), and television watching (0.31 lb per hour per day).

CONCLUSIONS

Specific dietary and lifestyle factors are independently associated with long-term weight gain, with a substantial aggregate effect and implications for strategies to prevent obesity. (Funded by the National Institutes of Health and others.).

Cardiovascular effects of calcium supplementation

Trials in normal older women and in patients with renal impairment suggest that calcium supplements increase the risk of cardiovascular disease. To further assess their safety, we recently conducted a meta-analysis of trials of calcium supplements, and found a 27-31% increase in risk of myocardial infarction and a 12-20% increase in risk of stroke. These findings are robust because they are based on pre-specified analyses of randomized, placebo-controlled trials and show consistent risk across the trials. The fact that cardiovascular events were not primary endpoints of any of these studies will introduce noise but not bias into the data. A recent re-analysis of the Women's Health Initiative suggests that co-administration of vitamin D with calcium does not lessen these adverse effects. The increased cardiovascular risk with calcium supplements is consistent with epidemiological data relating higher circulating calcium concentrations to cardiovascular disease in normal populations. There are several possible pathophysiological mechanisms for these effects, including effects on vascular calcification, on the function of vascular cells, and on blood coagulation. Calcium-sensing receptors might mediate some of these effects. Because calcium supplements produce small reductions in fracture risk and a small increase in cardiovascular risk, there may be no net benefit from their use. Food sources of calcium appear to produce similar benefits on bone density, although their effects on fracture are unclear. Since food sources have not been associated with adverse cardiovascular effects, they may be preferable. Available evidence suggests that other osteoporosis treatments are still effective without calcium co-administration.

Associations between dairy consumption and body weight: a review of the evidence and underlying mechanisms

As the incidence of obesity is reaching 'epidemic' proportions, there is currently widespread interest in the impact of dietary components on body-weight and food intake regulation. The majority of data available from both epidemiological and intervention studies provide evidence of a negative but modest association between milk and dairy product consumption and BMI and other measures of adiposity, with indications that higher intakes result in increased weight loss and lean tissue maintenance during energy restriction. The purported physiological and molecular mechanisms underlying the impact of dairy constituents on adiposity are incompletely understood but may include effects on lipolysis, lipogeneis and fatty acid absorption. Furthermore, accumulating evidence indicates an impact of dairy constituents, in particular whey protein derivatives, on appetite regulation and food intake. The present review summarises available data and provides an insight into the likely contribution of dairy foods to strategies aimed at appetite regulation, weight loss or the prevention of weight gain.

Biomarkers of milk fat and the risk of myocardial infarction in men and women: a prospective, matched case-control study

BACKGROUND

High intakes of saturated fat have been associated with cardiovascular disease, and milk fat is rich in saturated fat.

OBJECTIVE

The objective of this study was to investigate the association between the serum milk fat biomarkers pentadecanoic acid (15:0), heptadecanoic acid (17:0), and their sum (15:0+17:0) and a first myocardial infarction (MI).

DESIGN

The study design was a prospective case-control study nested within a large population-based cohort in Sweden. Included in the study were 444 cases (307 men) and 556 controls (308 men) matched on sex, age, date of examination, and geographic region. Clinical, anthropometric, biomarker fatty acid, physical activity, and dietary data were collected. The odds of a first MI were investigated by using conditional logistic regression.

RESULTS

In women, proportions of milk fat biomarkers in plasma phospholipids were significantly higher (P < 0.05) in controls than in cases and were, in general, negatively, albeit weakly, correlated with risk factors for metabolic syndrome. The crude standardized odds ratios of becoming an MI case were 0.74 (95% CI: 0.58, 0.94) in women and 0.91 (95% CI: 0.77, 1.1) in men. After multivariable adjustment for confounders, the inverse association remained in both sexes and was significant in women. In agreement with biomarker data, quartiles of reported intake of cheese (men and women) and fermented milk products (men) were inversely related to a first MI (P for trend < 0.05 for all).

CONCLUSIONS

Milk fat biomarkers were associated with a lower risk of developing a first MI, especially in women. This was partly confirmed in analysis of fermented milk and cheese intake. Components of metabolic syndrome were observed as potential intermediates for the risk relations.

Dairy food consumption and obesity-related chronic disease

Dairy food comprises a range of different products with varying nutritional components. In the context of a healthy diet, dairy food may provide protection against and amelioration of chronic diseases related to obesity. These include overweight, insulin resistance/metabolic syndrome/type 2 diabetes, hypertension/stroke, and cardiovascular disease. Eliciting how dairy food may have this impact represents a challenge for modern nutritional science and requires an integration of knowledge from observational studies of population dietary patterns and disease prevalence, and experimental studies testing the effect of dairy food consumption. It also benefits from the recent identification of biomarkers of dairy fat intake and from mechanistic studies that support the plausibility of the observed effects. Future research might discriminate between types of dairy foods and focus on the synergy provided by the food matrix, rather than simply the component parts of the food.

Dairy beverages and energy balance

High dairy intakes have been associated with lower rates of obesity in observational studies, but mechanisms to explain the association are lacking. A high intake of dairy protein reduces spontaneous food intake and may be one important mechanism, but more specific effects of dairy calcium seem to exist. We have found that high versus low calcium intakes from dairy products had no effect on 24-h energy expenditure or substrate oxidation rates, but fecal fat excretion increased approximately 2.5-fold on the high-calcium diets. In a meta-analysis of intervention studies we found that increasing dairy calcium intake by 1200mg/day resulted in increased fecal fat excretion by 5.2 (1.6-8.8) g/day. Newer research shows that humans possess taste receptors for calcium in the gastrointestinal tract and that signaling may be linked to appetite regulation. A new line of evidence suggests that an inadequate calcium intake during an energy restricted weight loss program may trigger hunger and impair compliance to the diet. These mechanisms may be part of the explanation for the protective effects of dairy products with regard to obesity and metabolic syndrome.

ISSN exercise & sport nutrition review: research & recommendations

Sports nutrition is a constantly evolving field with hundreds of research papers published annually. For this reason, keeping up to date with the literature is often difficult. This paper is a five year update of the sports nutrition review article published as the lead paper to launch the JISSN in 2004 and presents a well-referenced overview of the current state of the science related to how to optimize training and athletic performance through nutrition. More specifically, this paper provides an overview of: 1.) The definitional category of ergogenic aids and dietary supplements; 2.) How dietary supplements are legally regulated; 3.) How to evaluate the scientific merit of nutritional supplements; 4.) General nutritional strategies to optimize performance and enhance recovery; and, 5.) An overview of our current understanding of the ergogenic value of nutrition and dietary supplementation in regards to weight gain, weight loss, and performance enhancement. Our hope is that ISSN members and individuals interested in sports nutrition find this review useful in their daily practice and consultation with their clients.

Effects of calcium supplementation on lipids, blood pressure, and body composition in healthy older men: a randomized controlled trial

BACKGROUND

Calcium supplementation has been suggested to have beneficial effects on serum lipids, blood pressure, and body weight, but these possibilities have not been rigorously assessed in men.

OBJECTIVE

This study evaluated the effect of calcium supplementation on the change in the ratio of HDL to LDL cholesterol (primary endpoint) and on changes in cholesterol fractions, triglycerides, blood pressure, and body composition (secondary endpoints).

DESIGN

We carried out a randomized controlled trial of calcium supplementation in 323 generally healthy men over a period of 2 y. Subjects were randomly assigned to take placebo, 600 mg Ca/d, or 1200 mg Ca/d.

RESULTS

There was no significant treatment effect on the ratio of HDL to LDL cholesterol (P = 0.47) nor on weight, fat mass, lean mass, triglycerides, or total, LDL, or HDL cholesterol (P > 0.28 for all). There were downward trends in systolic and diastolic blood pressures within the calcium-supplemented groups, but there were no significant treatment effects over the whole trial period (P > 0.60). In a post hoc analysis of those with baseline calcium intakes below the median value (785 mg/d), blood pressures showed borderline treatment effects (P = 0.05-0.06 for changes at 2 y in those who received 1200 mg Ca/d compared with placebo: systolic, -4.2 mm Hg; diastolic, -3.3 mm Hg). Low magnesium intake showed a similar interaction. No treatment effects on weight or body composition were found.

CONCLUSIONS

These data do not show significant effects of calcium supplementation on serum lipids or body composition. Calcium supplementation in those with low dietary intakes may benefit blood pressure control. This trial was registered with the Australian Clinical Trials Registry as ACTRN 012605000274673.

Cell adhesion and spreading affect adipogenesis from embryonic stem cells: the role of calreticulin

Calreticulin is an endoplasmic reticulum-resident multifunctional protein, which has been shown to influence numerous cellular processes, including cell adhesion. In this study, we characterized the adhesive properties of embryonic stem cells (ESCs) lacking calreticulin and showed that adipogenesis from ESCs is directly and reciprocally controlled by the adhesive status of a cell, which in turn is modulated by calreticulin. Calreticulin-deficient ESCs are not only highly adipogenic but also show elevated calmodulin/CaMKII signaling and poor adhesiveness compared with the wild-type ESCs. Calreticulin deficiency leads to a disorganized cytoskeleton and low levels of focal adhesion-related proteins, such as vinculin, paxillin, and phosphorylated focal adhesion kinase, which cause limited focal adhesion formation and limited fibronectin deposition. Moreover, differentiation on nonadhesive substrata, which hinder cell spreading, promoted adipogenesis in the wild-type ESCs that normally have low adipogenic potential, causing a decrease in focal adhesion protein expression and an increase in calmodulin/CaMKII signaling. In contrast, inhibition of CaMKII effectively increased focal adhesion protein levels and inhibited adipogenesis in calreticulin-deficient ESCs, causing them to behave like the low adipogenic, wild-type ESCs. Thus, the adipogenic potential of ESCs is proportional to their calmodulin/CaMKII activity but is inversely related to their focal adhesion protein levels and degree of adhesiveness/spreading.

Investigation of the effect of high dairy diet on body mass index and body fat in overweight and obese children

OBJECTIVE

To investigate whether an increase in dairy food consumption improves the changes in BMI and adiposity in children on an energy restricted diet.

METHODS

Overweight and obese children (n = 120, age: 12-18 y, BMI: 27-40 kg/m2) were randomized to receive a calorie restricted diet providing a 500 kcal/d deficit from total energy expenditure and two (n = 40), three (n = 40) or four (n = 40) servings of dairy products/day. Anthropometric measurements in addition to serum hs-CRP and lipid profile were measured at baseline and after 12 weeks.

RESULTS

Among the 96 children who completed the study, significant reductions in overall BMI, BMI z-score, weight, total body fat percentage and total body fat mass were observed (p < 0.001) but these reductions were not significantly affected by increasing dairy intake (p > 0.05). Overall waist/hip ratio, Serum vitamin D and lipid profile did not change significantly (p > 0.05) apart from a significant increase in HDL-cholesterol (p < 0.001) which was independent of dairy intake (p > 0.05).

CONCLUSION

Increased intake of dairy products does not lead to an augmented change in BMI, weight and body fat in overweight and obese children beyond what is achieved by calorie restriction.

Associations between lactase persistence and the metabolic syndrome in a cross-sectional study in the Canary Islands

BACKGROUND

The single nucleotide polymorphism (SNP) LCT -13910 C>T, associated with genetically determined phenotypes of lactase persistence (LP) or non-persistence (LNP), was studied in relation to the metabolic syndrome (MS).

AIM OF THE STUDY

The aim was to determine if milk intake and MS are associated. We applied Mendelian randomization (MR). The SNP, LCT -13910 C>T, with the genotypes LP (TT/CT) and LNP (CC), was taken as a proxy for milk consumption.

METHODS

A representative sample of adults belonging to the Canary Islands Nutrition Survey (ENCA) in Spain aged 18-75 years (n = 551) was genotyped for the LCT -13910 C>T polymorphism. We used the International Diabetes Federation (IDF) criteria to define MS.

RESULTS

60% of the population was LP and 40% LNP. One hundred seven LP subjects (35.0%) and 53 LNP subjects (25.6%) showed MS (chi (2) = 5.04, p = 0.025). LP subjects showed a significantly higher odds ratio (OR) for MS than LNP subjects computed for the whole population: both the crude OR (1.56; 95% CI 1.06-2.31) and adjusted OR for sex, age, daily energy intake, physical activity and educational level (1.57; 95% CI 1.02-2.43). Adjusted OR for women with LP was 1.93; 95% CI 1.06-3.52.

CONCLUSIONS

The T allele of the SNP might constitute a nutrigenetic factor increasing the susceptibility of LP subjects, especially women, to develop MS in the Canary Islands.

Effect of dairy and non-dairy calcium on fecal fat excretion in lactose digester and maldigester obese adults

Background

The effect of dietary calcium on fecal fat excretion in lactose maldigestion is not known.

Objective

To investigate the effect of dairy and nondairy dietary calcium on fecal fat excretion in lactose digesters and maldigesters during moderate energy restriction.

Design

A randomized cross-over trial comparing the effect of 500 mg vs. 1500 mg dairy and nondairy calcium on fecal fat excretion in 34 healthy adults during moderate (− 30%) energy restriction diet-induced weight loss for 12 weeks. The participants were classified as lactose digester or maldigester on the basis of breath hydrogen test.

Measurements

Anthropometric parameters and body composition, resting energy expenditure, energy and nutrient intake, fecal fat, physical activity, blood pressure, blood and urine sampling for pertinent measurements.

Results

Fecal fat loss expressed as percent of fat intake was significantly higher with 1500 mg (high-Ca) compared to 500 mg (low-Ca) calcium intake per day (mean: 3.0%; the 95% CI: 2.3 to 3.7%; P <0.001) independent of calcium source and lactose digestion status.

Conclusions

During moderate energy restriction induced weight loss a high-Ca diet causes an increase in fecal fat excretion independent of calcium source. Calcium intake related fecal fat loss is also independent of the ability to digest lactose and it is not diminished over time.