Predicting Weight Loss Using Psychological and Behavioral Factors: The POUNDS LOST Trial.

CONTEXT: Eating habits and food craving are strongly correlated with weight status. It is currently not well understood how psychological and behavioral factors influence both weight loss and weight regain. OBJECTIVE: To examine the associations between psychological and behavioral predictors with weight changes and energy intake in a randomized controlled trial on weight loss. DESIGN AND SETTING: The Prevention of Obesity Using Novel Dietary Strategies is a dietary intervention trial that examined the efficacy of 4 diets on weight loss over 2 years. Participants were 811 overweight (body mass index, 25-40.9 kg/m2; age, 30-70 years) otherwise healthy adults. RESULTS: Every 1-point increase in craving score for high-fat foods at baseline was associated with greater weight loss (-1.62 kg, P = .0004) and a decrease in energy intake (r = -0.10, P = .01) and fat intake (r = -0.16, P < .0001) during the weight loss period. In contrast, craving for carbohydrates/starches was associated with both less weight loss (P < .0001) and more weight regain (P = .04). Greater cognitive restraint of eating at baseline was associated with both less weight loss (0.23 kg, P < .0001) and more weight regain (0.14 kg, P = .0027), whereas greater disinhibition of eating was only associated with more weight regain (0.12 kg, P = .01). CONCLUSIONS: Craving for high-fat foods is predictive of greater weight loss, whereas craving for carbohydrates is predictive of less weight loss. Cognitive restraint is predictive of less weight loss and more weight regain. Interventions targeting different psychological and behavioral factors can lead to greater success in weight loss.

Fifty Years of Behavioral/Lifestyle Interventions for Overweight and Obesity: Where Have We Been and Where Are We Going?

OBJECTIVE: This paper reviews the literature pertaining to the structure and content of intensive lifestyle interventions (ILIs) for overweight/obesity since Richard Stuart described this new treatment approach in 1967. A consensus opinion has formed that behavioral/lifestyle treatment of overweight and obesity should be viewed as a mainstream intervention for the treatment and prevention of type 2 diabetes and medical complications associated with obesity. METHODS: The development of modern ILIs and demonstration of their efficacy are compared by structure, content, and efficacy of four major randomized controlled trials: Diabetes Prevention Program (DPP), Look AHEAD, POUNDS Lost, and CALERIE. RESULTS: The results of these studies indicated that modification of lifestyle behaviors related to nutrition and physical activity can yield weight loss and prevention or improvement of a variety of medical conditions associated with obesity in a variety of subpopulations. CONCLUSIONS: Recommendations for the structure and length of behavioral/lifestyle interventions have been recently adopted by agencies and institutions that approve reimbursement for medical services. These recommendations represent a giant step in the effort to recognize ILIs as a mainstream approach for the treatment of obesity and comorbid medical conditions. Nevertheless, they do not adequately represent advances made since the publication of the DPP results.

A 2-Year Randomized Controlled Trial of Human Caloric Restriction: Feasibility and Effects on Predictors of Health Span and Longevity.

BACKGROUND: Caloric restriction (CR), energy intake reduced below ad libitum (AL) intake, increases life span in many species. The implications for humans can be clarified by randomized controlled trials of CR. METHODS: To determine CR's feasibility, safety, and effects on predictors of longevity, disease risk factors, and quality of life in nonobese humans aged 21-51 years, 218 persons were randomized to a 2-year intervention designed to achieve 25% CR or to AL diet. Outcomes were change from baseline resting metabolic rate adjusted for weight change ("RMR residual") and core temperature (primary); plasma triiodothyronine (T3) and tumor necrosis factor-α (secondary); and exploratory physiological and psychological measures. RESULTS: Body mass index averaged 25.1 (range: 21.9-28.0 kg/m(2)). Eighty-two percent of CR and 95% of AL participants completed the protocol. The CR group achieved 11.7±0.7 %CR (mean ± standard error) and maintained 10.4±0.4% weight loss. Weight change in AL was negligible. RMR residual decreased significantly more in CR than AL at 12 months (p = .04) but not 24 months (M24). Core temperature change differed little between groups. T3 decreased more in CR at M12 and M24 (p < .001), while tumor necrosis factor-α decreased significantly more only at M24 (p = .02). CR had larger decreases in cardiometabolic risk factors and in daily energy expenditure adjusted for weight change, without adverse effects on quality of life. CONCLUSIONS: Sustained CR is feasible in nonobese humans. The effects of the achieved CR on correlates of human survival and disease risk factors suggest potential benefits for aging-related outcomes that could be elucidated by further human studies.

An environmental intervention to prevent excess weight gain in African-American students: a pilot study.

PURPOSE: To examine the influence of an environmental intervention to prevent excess weight gain in African-American children. DESIGN: Single-group repeated measures. SETTING: The intervention was delivered to a school composed of African-American children. PARTICIPANTS: Approximately 45% (N = 77) of enrolled second through sixth grade students. INTERVENTION: The 18-month intervention was designed to alter the school environment to prevent excess weight gain by making healthier eating choices and physical activity opportunities more available. MEASURES: Body mass index percentile was the primary outcome variable. Body mass index z score was also calculated, and percent body fat, using bioelectrical impedance, was also measured. Total caloric intake (kilocalories) and percent kilocalories from fat, carbohydrate, and protein were measured by digital photography. Minutes of physical activity and sedentary behavior were selfreported. ANALYSIS: Mixed-models analysis was used with covarying baseline values. RESULTS: Boys maintained, whereas girls increased, percent body fat over 18 months (p = .027). All children decreased percent of kilocalories consumed from total and saturated fat and increased carbohydrate intake and self-reported physical activity during the intervention (p < .025). Body mass index z score, sedentary behavior, and total caloric intake were unchanged. CONCLUSION: The program may have resulted in maintenance of percent body fat in boys. The percent body fat in girls steadily increased, despite similar behavioral changes as boys. School-based interventions targeting African-American children should investigate strategies that can be effective across gender.

Effect of 6-month calorie restriction and exercise on serum and liver lipids and markers of liver function.

OBJECTIVE: Nonalcoholic fatty liver disease (NAFLD) and its association with insulin resistance are increasingly recognized as major health burdens. The main objectives of this study were to assess the relation between liver lipid content and serum lipids, markers of liver function and inflammation in healthy overweight subjects, and to determine whether caloric restriction (CR) (which improves insulin resistance) reduces liver lipids in association with these same measures. METHODS AND PROCEDURES: Forty-six white and black overweight men and women (BMI = 24.7-31.3 kg/m(2)) were randomized to "control (CO)" = 100% energy requirements; "CR" = 25%; "caloric restriction and increased structured exercise (CR+EX)"= 12.5% CR + 12.5% increase in energy expenditure through exercise; or "low-calorie diet (LCD)" = 15% weight loss by liquid diet followed by weight-maintenance, for 6 months. Liver lipid content was assessed by magnetic resonance spectroscopy (MRS) and computed tomography (CT). Lipid concentrations, markers of liver function (alanine aminotransferase (ALT), alkaline phosphatase (ALK)), and whole-body inflammation (tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP)) were measured in fasting blood. RESULTS: At baseline, increased liver lipid content (by MRS) correlated (P < 0.05) with elevated fasting triglyceride (r = 0.52), ALT (r = 0.42), and hsCRP (r = 0.33) concentrations after adjusting for sex, race, and alcohol consumption. With CR, liver lipid content was significantly lowered by CR, CR+EX, and LCD (detected by MRS only). The reduction in liver lipid content, however, was not significantly correlated with the reduction in triglycerides (r = 0.26; P = 0.11) or with the changes in ALT, high-density lipoprotein (HDL)-cholesterol, or markers of whole-body inflammation. DISCUSSION: CR may be beneficial for reducing liver lipid and lowering triglycerides in overweight subjects without known NAFLD.

Measurement of smoking outcome expectancies in children: the Smoking Consequences Questionnaire-Child.

A measure of smoking outcome expectancies was developed for children ages 7-12 years. Confirmatory factor analysis (CFA) was used to determine whether a 1-, 2-, 3-, or 4-factor solution was most appropriate for the data set. CFA revealed that the 3-factor model produced the most adequate fit (Positive Reinforcement, Negative Consequences, and Weight Control). The resulting 15-item measure was named the Smoking Consequences Questionnaire-Child (SCQ-C). The fit of the 3-dimensional structure was then examined separately for 3 age groups representing young (7- to 8-year-old), middle (9- to 10-year-old), and old (11- to 13-year-old) children. Overall, the 3-factor structure fit the data well for the 3 groups. As such, we examined the relations of the 3 scales with antecedent variables for the entire sample. The Positive Reinforcement scale was associated with children's smoking behavior and having a family member or peers who smoked. The Negative Consequences scale was inversely related to having a family member or peer who smoked.

Wise Mind project: a school-based environmental approach for preventing weight gain in children.

OBJECTIVE: The Wise Mind pilot study compared the efficacy of an environmental approach for prevention of inappropriate weight gain in children with an active control condition that used an environmental approach for modifying expectancies related to the use of alcohol, tobacco, and drugs. RESEARCH METHODS AND PROCEDURES: A total of 670 second to sixth grade students from four schools were enrolled in the study. The study spanned 2 academic years, and 586 students were available for evaluation at the end of the study. Two schools were randomly assigned to each treatment arm. The environmental approach for weight gain prevention focused on modification of eating habits and physical activity, and the active control group focused on modification of expectancies related to substance use. RESULTS: Using an intention to treat design, the study found no differences in weight gain prevention between the two interventions. The weight gain prevention program was associated with reduction of total caloric intake, reduction of dietary fat intake, reduction of protein intake, and increased physical activity in comparison with the active control group and relative to baseline. These changes in food intake were attributed to changes in food selections that resulted from modification of school cafeteria menus and food preparation. DISCUSSION: The Wise Mind school-based weight gain prevention program induced behavioral changes in healthy eating and physical activity but did not induce significant changes in body weight in comparison with the control arm. Recommendations for future research are provided.

Weight-related concerns associated with smoking in young children.

Studies have shown that weight concern is associated with smoking in adolescents. However, little is known about the relationship between weight concern and smoking in younger children. Analyses were conducted to determine whether children in elementary school who had tried smoking would possess greater weight concern than those who had not tried smoking. Results indicated that smokers possessed more general weight concern, F(1, 640)=5.619, p=.018, reported more dieting, F(1, 707)=11.757, p=.001, and endorsed greater concern with body size, F(1, 707)=4.113, p=.043, than non-smokers. Similar to adolescents, these results suggest that young children who have tried smoking are more concerned about weight than children who have not tried smoking.

Behavior and lifestyle: approaches to treatment of obesity.

The increasing prevalence of overweight and obesity in adults and children demonstrates a steadily growing epidemic. This rising rate of obesity is associated with obesity related comorbidities including cardiovascular disease, hypertension, some cancers, joint disease, and particularly, type 2 diabetes. Modest weight loss (5% to 10% of total body weight) through lifestyle intervention approaches has been found to have a beneficial effect on comorbid conditions, particularly hypertension and type 2 diabetes. Effective behavioral treatment of obesity involves modification of eating and physical activity patterns to yield negative energy balance. Research studies have found that interventions that combine a low-calorie diet, increased physical activity, and behavior therapy are most effective for weight loss and maintenance. Furthermore, extended length of treatment contact, weight loss satisfaction, and social support may promote positive long-term outcomes in obese adults and children.

Psychological and behavioral correlates of baseline BMI in the diabetes prevention program (DPP).

OBJECTIVE: To determine psychological and behavioral correlates of baseline BMI in the Diabetes Prevention Program (DPP). RESEARCH DESIGN AND METHODS: Of 1,079 DPP lifestyle intervention participants, 274 completed validated questionnaires at baseline assessing weight loss history, stage of change, self-efficacy, dietary restraint, emotional eating, binge eating, perceived stress, depression, and anxiety. RESULTS: The mean age of subjects was 52.5 years, 65% were women, and their mean BMI was 33.9 kg/m(2). Higher BMI correlated with more frequent weight cycling (r = 0.50, P < 0.0001) and efforts at weight loss (r = 0.34, P < 0.0001); younger age when first overweight (r = -0.42, P < 0.0001); lower exercise efficacy (r = -0.15, P = 0.015); lower weight loss efficacy (r = -0.21, P < 0.001); a less advanced stage of change for weight loss (r = -0.12, P = 0.04); more perceived stress (r = 0.14, P = 0.02); emotional eating (r = 0.19, P = 0.001); poor dietary restraint (r = -0.14, P = 0.02); binge eating frequency (r = 0.18, P = 0.004) and severity (r = 0.30, P < 0.0001); feeling deprived, angry, or upset while dieting (r = 0.27, P