David L. Katz

The Effectiveness of Worksite Nutrition and Physical Activity Interventions for Controlling Employee Overweight and Obesity. A Systematic Review

This report presents the results of a systematic review of the effectiveness of worksite nutrition and physical activity programs to promote healthy weight among employees. These results form the basis for the recommendation by the Task Force on Community Preventive Services on the use of these interventions. Weight-related outcomes, including weight in pounds or kilograms, BMI, and percentage body fat were used to assess effectiveness of these programs. This review found that worksite nutrition and physical activity programs achieve modest improvements in employee weight status at the 6-12-month follow-up. A pooled effect estimate of -2.8 pounds (95% CI=-4.6, -1.0) was found based on nine RCTs, and a decrease in BMI of -0.5 (95% CI=-0.8, -0.2) was found based on six RCTs. The findings appear to be applicable to both male and female employees, across a range of worksite settings. Most of the studies combined informational and behavioral strategies to influence diet and physical activity; fewer studies modified the work environment (e.g., cafeteria, exercise facilities) to promote healthy choices. Information about other effects, barriers to implementation, cost and cost effectiveness of interventions, and research gaps are also presented in this article. The findings of this systematic review can help inform decisions of employers, planners, researchers, and other public health decision makers.

Guide to community preventive servicesThe Effectiveness of Worksite Nutrition and Physical Activity Interventions for Controlling Employee Overweight and Obesity: A Systematic Review

This report presents the results of a systematic review of the effectiveness of worksite nutrition and physical activity programs to promote healthy weight among employees. These results form the basis for the recommendation by the Task Force on Community Preventive Services on the use of these interventions. Weight-related outcomes, including weight in pounds or kilograms, BMI, and percentage body fat were used to assess effectiveness of these programs. This review found that worksite nutrition and physical activity programs achieve modest improvements in employee weight status at the 6-12-month follow-up. A pooled effect estimate of -2.8 pounds (95% CI=-4.6, -1.0) was found based on nine RCTs, and a decrease in BMI of -0.5 (95% CI=-0.8, -0.2) was found based on six RCTs. The findings appear to be applicable to both male and female employees, across a range of worksite settings. Most of the studies combined informational and behavioral strategies to influence diet and physical activity; fewer studies modified the work environment (e.g., cafeteria, exercise facilities) to promote healthy choices. Information about other effects, barriers to implementation, cost and cost effectiveness of interventions, and research gaps are also presented in this article. The findings of this systematic review can help inform decisions of employers, planners, researchers, and other public health decision makers.

Self-reported weight and height: Implications for obesity research

BACKGROUND Self-reported weight and height are under- and over-reported, respectively, in epidemiologic studies. This tendency, which may adversely affect study operations, has not been evaluated among subjects being enrolled into a weight-loss program. METHODS Self-reported weight, height, and body mass index (BMI) were compared to measured values in 97 overweight or obese (BMI>27.3) women being enrolled into a randomized, controlled trial of two behavioral interventions for weight loss. The effects of demographic factors, baseline weight, baseline height, and baseline BMI on weight and height reporting were assessed. RESULTS There was a significant difference between measured and reported weight (mean difference=-3.75 lb, p=0.0001) and height (mean difference=+0.35 in., p=0.0007). The mean difference between measured and reported BMI was -1.14 kg/m(2) (p=0.0001). Unemployed, retired, or disabled women were more likely to under-report their BMI than employed women (p=0.001). Six percent of subjects who were initially considered eligible for the study on the basis of the self-report were eventually excluded from the study because they did not meet the inclusion criterion for BMI. CONCLUSIONS Obese women who seek weight-loss assistance tend to under-report their weight and over-report their height, suggesting that self-reported data are likely to be inaccurate. Misreporting is apparently influenced by employment and disability and has the potential to complicate recruitment of subjects for research studies.

Effects of Walnut Consumption on Endothelial Function in Type 2 Diabetic Subjects: A randomized controlled crossover trial

OBJECTIVE To determine the effects of daily walnut consumption on endothelial function, cardiovascular biomarkers, and anthropometric measures in type 2 diabetic individuals. RESEARCH DESIGN AND METHODS This study was a randomized, controlled, single-blind, crossover trial. Twenty-four participants with type 2 diabetes (mean age 58 years; 14 women and 10 men) were randomly assigned to one of the two possible sequence permutations to receive an ad libitum diet enriched with 56 g (366 kcal) walnuts/day and an ad libitum diet without walnuts for 8 weeks. Subjects underwent endothelial function testing (measured as flow-mediated dilatation [FMD]) and assessment of cardiovascular biomarkers before and after each 8-week treatment phase. The primary outcome measure was the change in FMD after 8 weeks. Secondary outcome measures included changes in plasma lipids, A1C, fasting glucose, insulin sensitivity, and anthropometric measures. RESULTS Endothelial function significantly improved after consumption of a walnut-enriched ad libitum diet compared with that after consumption of an ad libitum diet without walnuts (2.2 ± 1.7 vs. 1.2 ± 1.6%; P = 0.04). The walnut-enriched diet increased fasting serum glucose and lowered serum total cholesterol and LDL cholesterol from baseline (10.0 ± 20.5 mg/dl, P = 0.04; −9.7 ± 14.5 mg/dl, P < 0.01; and −7.7 ± 10 mg/dl, P < 0.01, respectively), although these changes were not significant compared with those for an ad libitum diet without walnuts. There were no significant changes in anthropometric measures, plasma A1C, and insulin sensitivity. CONCLUSIONS A walnut-enriched ad libitum diet improves endothelium-dependent vasodilatation in type 2 diabetic individuals, suggesting a potential reduction in overall cardiac risk.

Cocoa and Chocolate in Human Health and Disease

Cocoa contains more phenolic antioxidants than most foods. Flavonoids, including catechin, epicatechin, and procyanidins predominate in antioxidant activity. The tricyclic structure of the flavonoids determines antioxidant effects that scavenge reactive oxygen species, chelate Fe2+ and Cu+, inhibit enzymes, and upregulate antioxidant defenses. The epicatechin content of cocoa is primarily responsible for its favorable impact on vascular endothelium via its effect on both acute and chronic upregulation of nitric oxide production. Other cardiovascular effects are mediated through anti-inflammatory effects of cocoa polyphenols, and modulated through the activity of NF-κB. Antioxidant effects of cocoa may directly influence insulin resistance and, in turn, reduce risk for diabetes. Further, cocoa consumption may stimulate changes in redox-sensitive signaling pathways involved in gene expression and the immune response. Cocoa can protect nerves from injury and inflammation, protect the skin from oxidative damage from UV radiation in topical preparations, and have beneficial effects on satiety, cognitive function, and mood. As cocoa is predominantly consumed as energy-dense chocolate, potential detrimental effects of overconsumption exist, including increased risk of weight gain. Overall, research to date suggests that the benefits of moderate cocoa or dark chocolate consumption likely outweigh the risks.

American College of Preventive Medicine Practice Policy statement: Weight management counseling of overweight adults

On the basis of a review of the current literature and recommendations, the American College of Preventive Medicine presents a practice policy statement on weight management counseling of overweight adults.

Performance characteristics of NuVal and the Overall Nutritional Quality Index (ONQI)

BACKGROUND Improving diets has considerable potential to improve health, but progress in this area has been limited, and advice to increase fruit and vegetable intake has largely gone unheeded. OBJECTIVES Our objective was to test the performance characteristics of the Overall Nutritional Quality Index (ONQI), a tool designed to help improve dietary patterns one well-informed choice at a time. DESIGN The ONQI was developed by a multidisciplinary group of nutrition and public health scientists independent of food industry interests and is the basis for the NuVal Nutritional Guidance System. Dietary guidelines, existing nutritional scoring systems, and other pertinent scientific literature were reviewed. An algorithm incorporating >30 entries that represent both micro- and macronutrient properties of foods, as well as weighting coefficients representing epidemiologic associations between nutrients and health outcomes, was developed and subjected to consumer research and testing of performance characteristics. RESULTS ONQI and expert panel rankings correlated highly (R = 0.92, P < 0.001). In consumer testing, approximately 80% of >800 study participants indicated that the ONQI would influence their purchase intent. ONQI scoring distinguished the more-healthful DASH (Dietary Approaches to Stop Hypertension) diet (mean score: 46) from the typical American diet according to the National Health and Nutrition Examination Survey (NHANES) 2003-2006 (mean score: 26.5; P < 0.01). In linear regression analysis of the NHANES 2003-2006 populations (n = 15,900), the NuVal system was significantly associated with the Healthy Eating Index 2005 (P < 0.0001). Recently generated data from ongoing studies indicate favorable effects on purchase patterns and significant correlation with health outcomes in large cohorts of men and women followed for decades. CONCLUSION NuVal offers universally applicable nutrition guidance that is independent of food industry interests and is supported by consumer research and scientific evaluation of its performance characteristics.

Effects of sugar-sweetened and sugar-free cocoa on endothelial function in overweight adults.

BACKGROUND Studies of cocoa suggest an array of cardiovascular benefits; however, the effects of daily intake of sugar-free and sugar-sweetened cocoa beverages on endothelial function (EF) have yet to be established. METHODS 44 adults (BMI 25-35 kg/m2) participated in a randomized, controlled, crossover trial. Participants were randomly assigned to a treatment sequence: sugar-free cocoa beverage, sugar-sweetened cocoa beverage, and sugar-sweetened cocoa-free placebo. Treatments were administered daily for 6 weeks, with a 4-week washout period. RESULTS Cocoa ingestion improved EF measured as flow-mediated dilation (FMD) compared to placebo (sugar-free cocoa: change, 2.4% [95% CI, 1.5 to 3.2] vs. -0.8% [95% CI, -1.9 to 0.3]; difference, 3.2% [95% CI, 1.8 to 4.6]; p<0.001 and sugar-sweetened cocoa: change, 1.5% [95% CI, 0.6 to 2.4] vs. -0.8% [95% CI, -1.9 to 0.3]; difference, 2.3% [95% CI, 0.9 to 3.7]; p=0.002). The magnitude of improvement in FMD after consumption of sugar-free versus sugar-sweetened cocoa was greater, but not significantly. Other biomarkers of cardiac risk did not change appreciably from baseline. BMI remained stable throughout the study. CONCLUSIONS Daily cocoa ingestion improves EF independently of other biomarkers of cardiac risk, and does not cause weight gain. Sugar-free preparations may further augment endothelial function.

Partners reducing effects of diabetes (PREDICT): a diabetes prevention physical activity and dietary intervention through African-American churches

Type 2 diabetes is epidemic in the United States with greater incidence rates in African-American communities. Lifestyle interventions during the phase of insulin resistance mitigate cardiovascular risk and prevent diabetes. The primary aim of this study is to test the impact of a Community Health Advisor (CHA)-based diabetes prevention controlled intervention in urban African-American communities. In this controlled trial, church congregants in New Haven, CT, receiving a 1-year CHA-led diabetes prevention intervention were compared with church congregants in Bridgeport, CT, who did not receive an intervention. Outcome measures included physical activity, dietary pattern, anthropometric measure, social support, diabetes knowledge, nutrition and exercise self-efficacy. The results indicate that at the end of the 1-year intervention period, there were no significant differences observed between intervention and control groups. Possible explanations for the lack of change include difficulty in engaging the CHAs, variability in the CHA-led interventions, baseline discrepancies between the two sites which could not be fully controlled and loss to follow-up. The results indicate important obstacles which impeded the successful implementation of this intervention and lessons learned for future interventions.

Weight loss counseling by health care providers.

OBJECTIVES This study explores the pattern of weight loss counseling by health care providers in Connecticut and the associated weight loss efforts by patients. METHODS Data from the 1994 Connecticut Behavioral Risk Factor Surveillance System survey were analyzed to determine (1) the frequency of weight management counseling by health care providers of overweight adults with and without additional cardiovascular risk factors and (2) the current weight loss practices of overweight subjects. RESULTS Only 29% of all overweight respondents and fewer than half with additional cardiovascular risk factors, reported that they had been counseled to lose weight. CONCLUSIONS The findings suggest a need for more counseling of overweight persons, especially those with cardiovascular disease risk factors.