Vitamin D Supplementation for Prevention of Cancer: The D2d Cancer Outcomes (D2dCA) Ancillary Study.

Context: Observational studies suggest that low vitamin D status may be a risk factor for cancer.

Objective: In a population with prediabetes and overweight/obesity that is at higher risk of cancer than the general population, we sought to determine if vitamin D supplementation lowers the risk of cancer and precancers.

Methods: The Vitamin D and type 2 diabetes (D2d) cancer outcomes study (D2dCA) is an ancillary study to the D2d study, which was conducted at 22 academic medical centers in the United States.

Vitamin D Supplementation and Prevention of Type 2 Diabetes.

Background: Observational studies support an association between a low blood 25-hydroxyvitamin D level and the risk of type 2 diabetes. However, whether vitamin D supplementation lowers the risk of diabetes is unknown.

Methods: We randomly assigned adults who met at least two of three glycemic criteria for prediabetes (fasting plasma glucose level, 100 to 125 mg per deciliter; plasma glucose level 2 hours after a 75-g oral glucose load, 140 to 199 mg per deciliter; and glycated hemoglobin level, 5.

Vitamin D supplementation for prevention of cancer: The D2d cancer outcomes (D2dCA) study.

Evidence on biological plausibility from mechanistic studies and data from observational studies suggest that vitamin D may be linked to risk of several types of cancer. However, evidence from clinical trials evaluating the effect of vitamin D supplementation on cancer risk is limited. The Vitamin D and Type 2 Diabetes (D2d) study is a multi-center, randomized, placebo-controlled clinical trial conducted to examine the causal relationship between oral vitamin D supplementation and development of diabetes among overweight adults with prediabetes.

Association between environmental exposure and CD4+CD25+ regulatory T cells.

Background: It is considered that farm areas protect young patients from allergy and asthma due to high exposure to endotoxins.

Aim: To compare CD4+/CD25+ T-regulatory cells and forkhead transcription factor Foxp3 expression in asthmatic children allergic to house dust mites (HDM) living in rural and farm areas.

Materials And Methods: This was a prospective analysis of 35 children living in farm areas (n=19) and rural areas (n=16), aged 8-16, with allergic rhinitis (allergic to dust mites) and newly diagnosed asthma.

Body-composition changes in the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE)-2 study: a 2-y randomized controlled trial of calorie restriction in nonobese humans.

Calorie restriction (CR) retards aging and increases longevity in many animal models. However, it is unclear whether CR can be implemented in humans without adverse effects on body composition. We evaluated the effect of a 2-y CR regimen on body composition including the influence of sex and body mass index (BMI; in kg/m) among participants enrolled in CALERIE-2 (Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy), a multicenter, randomized controlled trial.

Nutrition Status of Primary School Students in Two Rural Regions of Guinea-Bissau.

Background: The nutrition status of primary schoolchildren in Africa has received relatively little attention in comparison to that of younger children. We surveyed primary school students in Guinea-Bissau, a nation that is among the poorest in the world.

Objective: Anthropometry and prevalence of anemia and vitamin A deficiency were assessed in schoolchildren participating in International Partnership for Human Development's school feeding program in 2 regions of Guinea-Bissau.

Long-term moderate calorie restriction inhibits inflammation without impairing cell-mediated immunity: a randomized controlled trial in non-obese humans.

Calorie restriction (CR) inhibits inflammation and slows aging in many animal species, but in rodents housed in pathogen-free facilities, CR impairs immunity against certain pathogens. However, little is known about the effects of long-term moderate CR on immune function in humans. In this multi-center, randomized clinical trial to determine CR's effect on inflammation and cell-mediated immunity, 218 healthy non-obese adults (20-50 y), were assigned 25% CR (n=143) or an ad-libitum (AL) diet (n=75), and outcomes tested at baseline, 12, and 24 months of CR.

Effects of carbohydrate quantity and glycemic index on resting metabolic rate and body composition during weight loss.

Objective: To examine the effects of diets varying in carbohydrate and glycemic index (GI) on changes in body composition, resting metabolic rate (RMR), and metabolic adaptation during and after weight loss.

Methods: Adults with obesity (n = 91) were randomized to one of four provided-food diets for 17 weeks. Diets differed in percentage energy from carbohydrate (55% or 70%) and GI (low or high) but were matched for protein, fiber, and energy.

Independent, additive effects of five dietary variables on ad libitum energy intake in a residential study.

Objective: To examine the relationship between dietary characteristics of self-selected foods and energy balance in a cafeteria-style dining hall.

Methods: Ad libitum dietary intake from a self-selection menu was measured over two days in 151 adults (70% female, mean age 41 years, mean BMI 24.9 kg/m(2) ).

Genetic and Environmental Influences on Eating Behavior - A Study of Twin Pairs Reared Apart or Reared Together.

This study examined the relative influence of genetic versus environmental factors on specific aspects of eating behavior. Adult monozygotic twins (22 pairs and 3 singleton reared apart, 38 pairs and 9 singleton reared together, age 18-76 years, BMI 17-43 kg/m) completed the Three Factor Eating Questionnaire. Genetic and environmental variance components were determined for the three eating behavior constructs and their subscales using model-fitting univariate and multivariate analyses.

Effect of Body Composition Methodology on Heritability Estimation of Body Fatness.

Heritability estimates of human body fatness vary widely and the contribution of body composition methodology to this variability is unknown. The effect of body composition methodology on estimations of genetic and environmental contributions to body fatness variation was examined in 78 adult male and female monozygotic twin pairs reared apart or together. Body composition was assessed by six methods - body mass index (BMI), dual energy x-ray absorptiometry (DXA), underwater weighing (UWW), total body water (TBW), bioelectric impedance (BIA), and skinfold thickness.

Low or moderate dietary energy restriction for long-term weight loss: what works best?

Theoretical calculations suggest that small daily reductions in energy intake can cumulatively lead to substantial weight loss, but experimental data to support these calculations are lacking. We conducted a 1-year randomized controlled pilot study of low (10%) or moderate (30%) energy restriction (ER) with diets differing in glycemic load in 38 overweight adults (mean +/- s.d.

Genetic and environmental influences on factors associated with cardiovascular disease and the metabolic syndrome.

The relative influence of genetics and the environment on factors associated with cardiovascular disease (CVD) and metabolic syndrome (MetS) remains unclear. We performed model-fitting analyses to quantify genetic, common environmental, and unique environmental variance components of factors associated with CVD and MetS [waist circumference, blood pressure, fasting plasma glucose and insulin, homeostatic model assessment of insulin resistance (HOMA-IR), and fasting plasma lipids] in adult male and female monozygotic twins reared apart or together. We also investigated whether MetS components share common influences.

Long-term effects of 2 energy-restricted diets differing in glycemic load on dietary adherence, body composition, and metabolism in CALERIE: a 1-y randomized controlled trial.

Background: There remains no consensus about the optimal dietary composition for sustained weight loss.

Objective: The objective was to examine the effects of 2 dietary macronutrient patterns with different glycemic loads on adherence to a prescribed regimen of calorie restriction (CR), weight and fat loss, and related variables.

Design: A randomized controlled trial (RCT) of diets with a high glycemic load (HG) or a low glycemic load (LG) at 30% CR was conducted in 34 healthy overweight adults with a mean (+/-SD) age of 35 +/- 6 y and body mass index (kg/m(2)) of 27.

Long Term Effects of Energy-Restricted Diets Differing in Glycemic Load on Metabolic Adaptation and Body Composition.

A randomized controlled trial of high glycemic load (HG) and low glycemic load (LG) diets with food provided for 6 months and self-administered for 6 additional months at 30% caloric restriction (CR) was performed in 29 overweight adults (mean+/-SD, age 35+/-5y; BMI 27.5+/-1.5 kg/m(2)).

Relative influence of diet and physical activity on body composition in urban Chinese adults.

Background: The relative influence of diet and physical activity on body fatness remains uncertain.

Objective: The objective of the study was to investigate associations of dietary variables and physical activity with body fatness in urban Chinese adults.

Design: We conducted a cross-sectional study in 130 weight-stable men and women aged 35-49 y.

Effects of a cereal rich in soluble fiber on body composition and dietary compliance during consumption of a hypocaloric diet.

Objectives: To investigate the effects of oats, a cereal rich in soluble fiber, on body composition changes and dietary compliance during consumption of a weight loss diet.

Methods: Subjects were 41 healthy men and women aged 18 to 78 years. Weight maintenance energy requirements were established over two weeks during consumption of a control diet with low soluble fiber content.

Meal palatability, substrate oxidation and blood glucose in young and older men.

We investigated the effects of food palatability on the thermic effect of feeding (TEF), substrate oxidation and circulating glucose and insulin. Healthy young men (23.4+/-1.

Dietary determinants of energy intake and weight regulation in healthy adults.

Until recently, the percentage of energy from dietary fat has been considered a primary determinant of body fatness. This review covers recent studies from our laboratory that challenge this notion. High and low fat diets matched for energy density, palatability and fiber resulted in similar mean voluntary energy intakes over 9 d; analysis of the individual foods in these diets showed that energy density and palatability were significant determinants of energy intake, independent of fat content.

Overeating in America: association between restaurant food consumption and body fatness in healthy adult men and women ages 19 to 80.

Purpose: To examine the association between the frequency of consuming restaurant food and body fatness in adults.

Research Methods And Procedures: Usual free-living dietary intake and the frequency of consuming food from seven different restaurant types (fried chicken, burger, pizza, Chinese, Mexican, fried fish, and "other") were assessed by food frequency questionnaire in 73 healthy men and women [ages 19 to 80, body mass index (BMI) 18 to 33]. In addition, body fatness (percent weight) was determined by hydrostatic weighing, and physical activity and other lifestyle parameters were assessed by questionnaire.

Dietary variety within food groups: association with energy intake and body fatness in men and women.

Background: Short-term experimental studies suggest that dietary variety may influence body fatness but no long-term human studies have been reported.

Objective: The purpose of this study was to determine whether dietary variety within food groups influences energy intake and body fatness.

Design: Seventy-one healthy men and women (aged 20-80 y), who provided accurate reports of dietary intake and completed a body-composition assessment, were studied.

Relationship between circulating leptin and energy expenditure in adult men and women aged 18 years to 81 years.

Recent studies suggest that leptin may be an important metabolic signal for energy regulation in rodents, but the role of leptin in human energy regulation remains uncertain. Because adaptive variations in energy expenditure play an important role in human energy regulation, we investigated the relationship between leptin and energy expenditure parameters in 61 weight-stable men and women aged 18 years to 81 years who were not obese. Measurements were made of circulating leptin in the fasting state, body fat and fat free mass, resting metabolic rate (n = 61), free-living total energy expenditure (n = 52), and the thermic effect of feeding (n = 33).

Effects of age on energy expenditure and substrate oxidation during experimental underfeeding in healthy men.

Relatively little is known about the influence of age on energy regulation during energy imbalance. We compared the effects of underfeeding on changes in energy expenditure, substrate oxidation, and body energy loss between young men (age 22.0 +/- 0.