Examining social influence on participation and outcomes among a network of behavioral weight-loss intervention enrollees.

Research suggests that social networks, social support, and social influence are associated with weight trajectories among treatment- and non-treatment-seeking individuals. This study examined the impact of having a social contact who participated in the same group behavioral weight-control intervention in the absence of specific social support training on women engaged in a weight-loss program. Participants (n = 92; 100% female; 54% black; mean age: 46 ± 10 years; mean BMI: 38 ± 6) were grouped based upon whether or not they reported a social contact enrolled previously/concurrently in our behavioral weight-control studies. Primary outcomes were 6-month weight change and treatment adherence (session attendance and self-monitoring). Half of the participants (53%) indicated that they had a social contact; black women were more likely to report a social contact than white women (67.3% versus 39.5%; P < 0.01). Among participants with a social contact, 67% reported at least one contact as instrumental in the decision to enroll in the program. Those with a contact lost more weight (5.9 versus 3.7 kg; P = 0.04), attended more group sessions (74% versus 54%; P < 0.01), and submitted more self-monitoring journals (69% versus 54%; P = 0.01) than those without a contact. Participants' weight change was inversely associated with social contacts' weight change (P = 0.04). There was no association between participant and contact's group attendance or self-monitoring. Social networks may be a promising vehicle for recruiting and engaging women in a behavioral weight-loss program, particularly black women. The role of a natural social contact deserves further investigation.

Adolescencia prevenida: pérfil psicológico del adolescente rural del Chaco medido con el cuestionario sucesos de vida / Prevented Adolescence: psychological profile of rural teenager of the Chaco zone measured with the questionnaire sucesos de vida

El propósito de este estudio, que forma parte de una Macro Investigación denominada “Adolescencia Prevenida”, es identificar el perfil psicológico positivo y negativo del adolescente paraguayo rural de la Zona Chaco (Villa Hayes – Cerrito), de acuerdo a las 7 áreas (Familiar, Social, Personal, Escolar, Logros y Fracasos, Salud, problemas de Conducta) evaluadas por el Cuestionario Sucesos de Vida del Adolescente, en una muestra de 89 participantes, de los cuales uno fue eliminado, quedando un total de 88, siendo 54 mujeres y 34 varones. El diseño utilizado es de tipo transversal, ex - post- facto y comparativo. Los datos fueron sometidos a Análisis cuantitativo y cualitativo (intra e inter muestral). El análisis de datos aplicó la Prueba Estadística t de Student, con una confiabilidad del 95%. Los resultados indicaron en cuanto al Perfil Positivo y Negativo, la ausencia de diferencias significativas en las medias, en la mayoría de las áreas. No se reportan criterios de disfuncionalidad en varones como en mujeres, en lo que respecta al Perfil Negativo, tampoco se registra en las edades estudiadas, del Tercer Ciclo de la Educación Escolar Básica, y de la Educación Media.

Does using the Internet facilitate the maintenance of weight loss?

OBJECTIVE: The purpose of this study was to investigate the effectiveness of a weight maintenance program conducted over the Internet. DESIGN: Longitudinal, clinical behavioral weight loss trial with 6-month in-person behavioral obesity treatment followed by a 12-month maintenance program conducted both in-person (frequent in-person support; F-IPS, minimal in-person support; M-IPS) and over the Internet (Internet support; IS). SUBJECTS: A total of 122 healthy, overweight adults (age=48.4+/-9.6, BMI=32.2+/-4.5 kg/m(2), 18 male) MEASUREMENTS: Body weight, dietary intake, energy expended in physical activity, attendance, self-monitoring, comfort with technology. RESULTS: Results (n=101) showed that weight loss did not differ by condition during treatment (8.0+/-5 vs 11+/-6.5 vs 9.8+/-5.9 kg, P=0.27 for IS, M-IPS and F-IPS, respectively). The IS condition gained significantly more weight than the F-IPS group during the first 6 months of weight maintenance (+2.2+/-3.8 vs 0+/-4 kg, P<0.05) and sustained a significantly smaller weight loss than both in-person support groups at the 1 y follow-up (-5.7+/-5.9 vs -10.4+/-9.3 vs -10.4+/-6.3 kg, P<0.05 for IS, M-IPS and F-IPS, respectively). Attendance at maintenance meetings was greater for the F-IPS than the IS condition over the 1 y maintenance program (54 vs 39%, P=0.04). Acceptability of assigned condition was higher for subjects in the F-IPS than IS condition. CONCLUSION: The results of this study suggest that Internet support does not appear to be as effective as minimal or frequent intensive in-person therapist support for facilitating the long-term maintenance of weight loss.

Calorie restriction is more effective for obesity treatment than dietary fat restriction.

Recent evidence suggests that dietary fat intake may be more strongly associated than total energy intake to the development and maintenance of obesity. The objective of this study was to determine whether dietary fat restriction would promote more favorable changes in body weight, body composition, resting metabolic rate (RMR), eating behavior, and dietary adherence than calorie restriction. Sixty-five obese women and 15 obese men were recruited and randomly assigned to calorie restriction (1000-1200 kcal/day) or fat restriction (22-26 g/day). Subjects participated in a 24-week behavioral weight loss program. Forty-eight subjects completed assessments at all four time points-baseline and 6, 12, and 18 months. Weight loss was significantly greater in the low calorie (LC) group (-11.2 versus -6.1 kg, p<.001) and was maintained better at the 18-month assessment (-7.5 versus -1.8 kg, p< or =.001). There was a significantly greater decrease in percent body fat and RMR for the LC group with only percent body fat still significantly lower at 18 months. Subjects in the LC group consumed significantly fewer calories, less carbohydrates, and the same amount of fat as those in the low fat (LF) condition, however, calorie and carbohydrate intake were decreasing for LF subjects by the 12- and 18-month assessments. There were no long-term differences in most measured predictors of dietary adherence. Dietary fat restriction did not prove to be superior to calorie restriction, thus strengthening the public health message that calories do count.

The efficacy of dietary fat vs. total energy restriction for weight loss.

OBJECTIVE: Dietary fat restriction is currently being promoted as a weight loss strategy. However, previous investigations suggest that fat restriction alone may not be more beneficial than total energy restriction for the treatment of obesity. The purpose of this project was to assess whether an energy-restricted or fat-restricted diet was more effective at promoting weight loss, improving eating behaviors, and reducing barriers to dietary adherence. RESEARCH METHODS AND PROCEDURES: Eighty individuals (15 men and 65 women) were randomized into the two treatment conditions. Subjects were 120% to 140% of ideal body weight and 25 years to 45 years old. Treatment consisted of 24 weeks of dietary fat (22 g/day to 26 g/day) or energy restriction (4,186 kJ/day to 5,023 kJ/day), including behavior modification and exercise. Body weight change, dietary intake, eating behaviors, and barriers to adherence were measured at baseline and after treatment. RESULTS: Results show that subjects in the energy-restricted condition lost over twice as much weight as those in the fat-restricted group (11.5 kg vs. 5.2 kg). Additionally, subjects in the low-energy condition had greater improvements in eating behavior scores, enhanced feelings of wellness, a greater distaste for dietary fat, and no more pronounced feelings of deprivation than did those in the fat-restricted condition. DISCUSSION: An energy-restricted diet produces greater short-term weight loss than dietary fat restriction without many of the negative consequences commonly attributed to reducing energy intake.

Weight loss in the clinical setting: applications for cardiac rehabilitation.

Obese coronary patients could benefit significantly from weight reduction. Unfortunately, weight management is not considered a standard component of cardiac rehabilitation programs. This article reviews the characteristics, approach and outcome data for behavioral weigh loss programs. Strategies for implementing a behavior modification treatment as part of a cardiac rehabilitation program are discussed.

Food preferences predict eating behavior of very young Mohawk children.

OBJECTIVE: To collect baseline data on energy and nutrient intake and nutrition knowledge, attitudes, and behavior of very young Mohawk children to assist the community in planning an appropriate, targeted nutrition and exercise intervention. DESIGN: Energy and nutrient intake data were collected from 24-hour recalls conducted in the children's homes. Nutrition knowledge, attitudes, and behavior were assessed using a 38-item questionnaire that asked children to report on what foods they like the best, eat most of the time, and think are healthful. The questionnaire was completed in an elementary school on the reservation. Before data collection, we hypothesized that the average diet of the Mohawk children would not meet national dietary recommendations. SUBJECTS: One hundred forty-three children, prekindergarten through third grade (aged 4 to 9 years), completed the 24-hour recalls and the questionnaire. An additional 136 children, also prekindergarten through third grade, completed the questionnaire (n = 279). STATISTICS: Analysis of variance with a Scheffe's multiple-comparison test was used to test for differences among grades and genders for energy and nutrient intake and questionnaire scores. Multiple regression analysis was used to assess the relationship between eating behavior and selected variables. RESULTS: A mean daily energy intake of 1,980 kcal consisted of 34% fat, 13% protein, and 52% carbohydrate with 13 g fiber and 235 mg cholesterol. Food preferences were the strongest predictor of behavior, they explained 71% of the variation in the behavior score. APPLICATIONS: The major finding of this study, that food preferences are the strongest predictor of reported eating behavior in very young Mohawk children, has implications for behavior change interventions. Focusing on changing what children like to eat, through repeated exposure to new foods in a positive social context, is more likely to change what foods they choose than is simple nutrition education.

Amelioration of the inhibition of fibrinolysis in elderly, obese subjects by moderate energy intake restriction.

A possible cause of accelerated atherothrombosis in the syndrome of insulin resistance appears to be an elevated blood concentration of plasminogen activator inhibitor type-1 (PAI-1). Insulin resistance occurs with aging, attributable partly to increased adiposity. Scarce information exists regarding the effects of weight loss in elderly, obese individuals on PAI-1 concentrations. Consequently, weight loss (9 +/- 1 kg) was induced by energy intake restriction in 19 elderly, obese individuals, and its effect on fibrinolytic system peptides was measured. Initially elevated PAI-1 concentrations decreased by 50%, with a simultaneous decrease in the concentration of tissue-type plasminogen activator (t-PA)/PAI-1 complexes but no significant change in t-PA suggested a decrease in inhibition of the fibrinolytic system. The concentration of plasmin/antiplasmin complexes (PAP complex) increased by approximately 20%, indicating augmented fibrinolytic system activity. The decline in PAI-1 correlated with that of the decrease in body weight (r = 0.5, P < 0.05) and fat mass losses (r = 0.46, P < 0.05). The increase in PAP complexes correlated with weight and fat mass losses (r = 0.4 and r = 0.46, respectively; P < 0.05 for both). No correlation was seen between fibrinolytic system variables and baseline concentrations of substrates or insulin, but the change in PAI-1 correlated with the change in plasma triacylglycerols (r = 0.58, P < 0.05). Results indicate that energy restriction sufficient to induce moderate weight loss leads to diminution of elevated plasma PAI-1 and relief of inhibition of the fibrinolytic system in elderly, obese subjects. To the extent that these changes are associated with a decrease in the progression of vasculopathy, weight loss in elderly, obese individuals may be a useful means to reduce cardiovascular morbidity and mortality.

Decrease in fat oxidation following a meal in weight-reduced individuals: a possible mechanism for weight recidivism.

This study examined the effect that dietary-induced weight loss has on body composition, energy metabolism, and substrate oxidation at rest and during the 5-hour period following a meal. Twenty older (age:mean +/- SE, 61 +/- 1 years; range, 56 to 70 y) obese (body mass index > 32 kg/m2) subjects (12 women, eight men) completed an 11-week dietary restriction program in which they lost 9 +/- l kg. Fat and fat-free mass were reduced (P < .05) by 15% and 5%, respectively. Resting metabolic rate decreased by 15% (P < .05). Overall, weight loss did not alter the percentage of energy derived from fat sources (approximately 47% of energy) under resting conditions. In contrast, the percentage of calories derived from fat during the 5-hour postmeal period decreased from baseline to post-weight loss from 38% +/- 3% to 26% +/- 4% (P < .05) of total calories expended. The reduction in fat oxidation subsequent to a meal may facilitate fat storage, and may be one mechanism by which one regains weight following weight loss.

Contrasting effects of resistance and aerobic training on body composition and metabolism after diet-induced weight loss.

This study examined whether exercise training facilitates maintenance of body weight at reduced levels following weight loss by attenuating weight loss-induced reductions in resting metabolism and fat oxidation. The effects of 12 weeks (three times per week) of either aerobic or weight training exercise on body weight, body composition, and energy metabolism during rest and following a meal in 18 older (mean +/- SE, 61 +/- 1 years; range, 56 to 70) subjects who had recently lost a mean of 9 +/- 1 kg were studied. During the exercise training period, the aerobic training group (five women, four men) had a significant (P < .05) reduction in body weight (-2.5 +/- 0.6 kg) as compared with the weight training group (five women, four men) (0.4 +/- 0.9 kg). Eight of nine aerobic training subjects lost additional weight, while six of nine weight training subjects gained weight. Neither type of training reversed the depressions in resting metabolism or fat oxidation rates (ie, resting or postprandial) that had occurred as a consequence of the prior weight loss. Thus, alterations in resting metabolism or fat oxidation (resting or postprandial) do not appear to be the mechanism(s) by which exercise training facilitates maintenance of diet-induced weight loss.