Stable behaviors associated with adults' 10-year change in body mass index and likelihood of gain at the waist

Does physical activity prevent weight gain--a systematic review

This paper is a systematic review of research data on associations between physical activity and weight gain, with or without prior weight reduction. The selected studies were restricted to Caucasian (white) adults. Most studies with data on physical activity collected at follow-up, found an inverse association between physical activity and long-term weight gain. This finding was present in studies both with and without prior weight reduction. Prospective studies with physical activity measured at baseline, and randomized weight reduction interventions, gave inconsistent results regarding the effects of increased physical activity on weight change. The weighted mean weight regain in randomized studies with or without exercise training was 0.28 and 0.33 kg/month, respectively. Based on observational studies, it seemed that an actual increase in energy expenditure of physical activity of approximately 6300-8400 kJ/week (1500-2000 kcal/week) is associated with improved weight maintenance. This is more than was prescribed in most randomized trials, and certainly more than the participants actually achieved. Adherence to a prescribed exercise programme remains a big challenge. Before new methods to improve exercise adherence are found, the role of prescribed physical activity in prevention of weight gain remains modest.

A descriptive study of weight loss maintenance: 6 and 15 year follow-up of initially overweight adults

OBJECTIVE

To describe factors associated with long-term maintenance of weight loss.

DESIGN AND SUBJECTS

We identified initially overweight individuals (body mass index >27 kg/m2, n=911) from the nationwide Finnish Twin Cohort and studied those who lost at least 5% of their body weight between 1975 and 1981. Subjects who had maintained weight loss until 1990 (38 men, 17 women) were compared to both regainers (28 men, 26 women) and the other overweight subjects in the cohort.

MEASUREMENTS

Self-report data on weight, height, health behaviours and perceived well-being; self-report and register-based data on health status and use of medication.

RESULTS

Only 6% of all overweight individuals lost and maintained at least 5% weight loss. In men weight loss maintenance was associated with a low level of stress and health-promoting behaviours but also with medical problems. Failure to maintain weight loss seemed to be associated with stressful life and past high alcohol intake. In women weight loss maintenance was associated with low initial well-being and health-compromising behaviours that improved after weight loss.

CONCLUSION

Long-term weight loss maintenance is rare. Predictors of weight loss maintenance are different between women and men. International Journal of Obesity (2000)24, 116-125

Determinants of dietary intake in a sample of white and Mexican-American children

OBJECTIVE

To assess the influence of several potential psychosocial determinants on children's eating behavior.

PARTICIPANTS

Three hundred fifty-one Mexican-American and non-Hispanic white children (mean age = 4.4 years old at baseline) participated in the San Diego Study of Children's Activity and Nutrition for up to 2.5 years.

METHODS

Child's eating behavior was described by 3 dependent variables: total energy, percentage energy from fat, and sodium intake per 1,000 kcal. Dietary information was collected 4 days a year using a 24-hour food intake record, which was a combination of direct observation and interviews with food preparers. The 35 predictor variables from child, parental, demographic, and environmental domains were collected by behavioral observation, interviewer-administered questionnaires, and physical measurements.

STATISTICAL ANALYSES

Bivariate and regression analyses via mixed linear models were performed.

RESULTS

Variables from the children's domain (such as skinfold thickness and weight) had the strongest associations with energy intake; parental variables (such as fat avoidance behavior and prompts to increase children's food intake) were associated with child's percentage energy from fat and sodium intake. In regression analyses, parsimonious subsets of variables accounted for 46% of variance in energy intake (3 variables), 40% of the variance in percentage of energy from fat (4 variables), and 44% of variance in sodium intake per 1,000 kcal energy (1 variable) in between-subject variance components.

CONCLUSIONS

Fat and sodium intake of children may be improved by improving parents' nutrition habits and by having parents encourage children to eat a healthful diet. Few modifiable correlates of children's energy intake were identified.

Are geographic regions with high income inequality associated with risk of abdominal weight gain?

Geographic regions characterized by income inequality are associated with adverse mortality statistics, but the pathophysiologic mechanisms that mediate this ecologic relationship have not been elucidated. This study used a United States mail survey of 34158 male and 42741 female healthy-adult volunteers to test the association between residence in geographic regions with relative income inequality and the likelihood of weight gain at the waist. Respondents came from 21 states that were characterized by the household income inequality (HII) index, a measure reflecting the proportion of total income received by the more well off 50% of households in the state. The main outcome measure was self-reported weight gain mainly at the waist as opposed to weight gain at other anatomic sites. After controlling for age, other individual-level factors, and each state's median household income, men's likelihood of weight gain at the waist was positively associated (p = 0.0008) with the HII index. Men from states with a high HII (households above the median receive 81.6% to 82.6% of the income) described weight gain at the waist more often than men from states with a low HII (households above the median receive 77.0% to 78.5% of the income) (odds ratio = 1.12, 95% confidence interval 1.03 to 1.22). Women's results showed a non-significant trend in the same direction. An association between ecologically defined socio-environmental stress and abdominal obesity may help to clarify the pathophysiologic pathways leading to several major chronic diseases.