Time filter

Source Type

Washington, DC, United States

Barnard N.D.,Washington Center for Clinical Research | Barnard N.D.,George Washington University
American Journal of Clinical Nutrition | Year: 2010

The increase in childhood obesity mainly reflects increased energy intake. However, it is not clear which food categories are responsible for this increase. Food availability data, which are calculated from annual food production, imports, beginning stocks, subtracting exports, ending stocks, and nonfood uses, provide clues about which categories are the primary contributors. Data from 1909 to 2007 show increases in per capita availability of several product classes: added oils increased from 16.1 to 39.4 kg/y, meat increased from 56.3 to 91.2 kg/y, cheese increased from 1.7 to 14.9 kg/y, and frozen dairy products increased from 0.7 to 11.5 kg/y. From 1970 to 2007, per capita availability of sweeteners increased from 54.1 to 62.0 kg/y. Carbonated beverage availability has increased, partly at the expense of fluid milk. Flour and cereal availability decreased from 1909 until the late 1960s but rebounded thereafter. Availability of fruit, fruit juices, and vegetables has increased. We conclude that the major contributors to increased energy intake over the last century are oils, shortening, meat, cheese, and frozen desserts, with more recent increases in added sweeteners, fruit, fruit juices, and vegetables. These changes may have influenced the prevalence of childhood obesity. © 2010 American Society for Nutrition.

Turner-McGrievy G.M.,University of North Carolina at Chapel Hill | Jenkins D.J.A.,University of Toronto | Jenkins D.J.A.,Clinical Nutrition and Risk Factor Modification Center | Barnard N.D.,George Washington University | And 4 more authors.
Journal of Nutrition | Year: 2011

This study assessed the effect of changes in glycemic index (GI) and load (GL) on weight loss and glycated hemoglobin (HbA1c) among individuals with type 2 diabetes beginning a vegan diet or diet following the 2003 American Diabetes Association (ADA) recommendations. The study was a 22-wk, randomized trial of 99 participants with type 2 diabetes who were counseled to follow 1 of 2 diet treatments. GI and GL changes were assessed based on 3-d dietary records. The relationships between GI/GL and changes in weight and HbA1C were calculated. In an intention-to-treat analysis (n = 99), the vegan group reduced GI to a greater extent than the ADA group (P < 0.05), but GL was reduced further in the ADA than the vegan group (P < 0.001). GI predicted changes in weight (P = 0.001), adjusting for changes in fiber, carbohydrate, fat, alcohol, energy intake, steps per day, group, and demographics, such that for every point decrease in GI, participants lost ~0.2 kg (0.44 lb). GI was not a predictor for changes in HbA1C after controlling for weight loss (P = 0.33). Weight loss was a predictor of changes in HbA1C (P = 0.047). GL was not related to weight loss or changes in HbA1C. A low-GI diet appears to be one of the determinants of success of a vegan or ADA diet in reducing body weight among people with type 2 diabetes. The reduction of body weight, in turn, was predictive of decreasing HbA1C. © 2011 American Society for Nutrition.

Levin S.M.,Washington Center for Clinical Research | Ferdowsian H.R.,Washington Center for Clinical Research | Ferdowsian H.R.,George Washington University | Hoover V.J.,University of Florida | And 3 more authors.
Public Health Nutrition | Year: 2010

Objective To examine whether a worksite nutrition programme using a low-fat vegan diet could significantly improve nutritional intake.Design At two corporate sites of the Government Employees Insurance Company, employees who were either overweight (BMI 25 kg/m2) and/or had type 2 diabetes participated in a 22-week worksite-based dietary intervention study.Setting At the intervention site, participants were asked to follow a low-fat vegan diet and participate in weekly group meetings that included instruction and group support (intervention group). At the control site, participants received no instruction (control group). At weeks 0 and 22, participants completed 3 d dietary records to assess energy and nutrient intake.Subjects A total of 109 participants (sixty-five intervention and forty-four control).Results In the intervention group, reported intake of total fat, trans fat, saturated fat and cholesterol decreased significantly (P 0001), as did energy and protein (P = 001), and vitamin B12 (P = 0002), compared with the control group. Intake (exclusive of any use of nutritional supplements) of carbohydrate, fibre, vitamin C, magnesium and potassium increased significantly (P 00001), as did that for -carotene (P = 00004), total vitamin A activity (P = 0004), vitamin K (P = 001) and sodium (P = 004) in the intervention group, compared with the control group.Conclusions The present study suggests that a worksite vegan nutrition programme increases intakes of protective nutrients, such as fibre, folate and vitamin C, and decreases intakes of total fat, saturated fat and cholesterol. © 2010 The Authors.

Berkow S.E.,George Mason University | Barnard N.,Washington Center for Clinical Research | Eckart J.,Physicians Committee for Responsible Medicine | Katcher H.,Washington Center for Clinical Research
Canadian Journal of Dietetic Practice and Research | Year: 2010

Many health conditions are treated, at least in part, by therapeutic diets. Although the success of any intervention depends on its acceptability to the patient, the acceptability of therapeutic diets and factors that infuence it have been largely neglected in nutrition research. A working definition of acceptability is proposed and an examination and summary are provided of available data on the acceptability of common diet regimens used for medical conditions. The goal is to suggest ways to improve the success of therapeutic diets. The proposed working definition of "acceptability" refers to the user's judgment of the advantages and disadvantages of a therapeutic diet-in relation to palatability, costs, and efects on eating behaviour and health-that influence the likelihood of adherence. Very low-calorie, reduced-fat omnivorous, vegetarian and vegan, and low-carbohydrate diets all achieve acceptability among the majority of users in studies of up to one year, in terms of attrition and adherence rates and results of questionnaires assessing eating behaviours. Longer studies are fewer, but they suggest that vegetarian, vegan, and reduced-fat diets are acceptable, as indicated by sustained changes in nutrient intake. Few studies of this length have been published for very low-calorie or low-carbohydrate diets. Long-term studies of adherence and acceptability of these and other therapeutic diets are warranted.

Ferdowsian H.R.,George Washington University | Ferdowsian H.R.,Washington Center for Clinical Research | Ferdowsian H.R.,Unity Healthcare LLC | Barnard N.D.,George Washington University | And 6 more authors.
American Journal of Health Promotion | Year: 2010

Purpose: To determine whether a multicomponent nutrition intervention program at a corporate site reduces body weight and improves other cardiovascular risk factors in overweight individuals. Design: Prospective clinical intervention study. Subjects/Setting: Employees of the Government Employees Insurance Company (GEICO) (N = 113), aged 21 to 65 years, with a body mass index ≥ 25 kg/m2 and/or previous diagnosis of type 2 diabetes. Intervention: A 22-week intervention including a low-fat, vegan diet. Measures: Changes in body weight, anthropometric measures, blood pressure, lipid profile, and dietary intake. Analysis: Multivariate analyses of variance were calculated for clinical and nutrient measures, followed by univariate analyses of variance, to determine the significance of differences between groups in changes over lime. Results: Intervention-group participants experienced greater weight changes compared with control-group participants (mean,-5.1 [SE,.6] kgvs. +.1 [SE,.6] kg, p <.0001), as well as greater changes in waist circumference (mean,-4.7 [SE,.6] cm vs. +.8 [SE,.6] cm, p <.0001) and waist.hip ratio (mean,-.006 [SE,.003] vs. +.014 [SE,.005], p =.0007). Weight loss of 5% of body weight was more frequently observed in the intervention group (48.5%) compared with the control group (11.1%) (χ2[l,N= 113]= 16.99, p <.0001). Conclusions: Among individuals volunteering for a 22-week worksite research study, an intervention using a low-fat, vegan diet effectively reduced body weight and waist circumference. Copyright © 2010 by American Journal of Health Promotion, Inc.

Discover hidden collaborations