Is dieting good for you? Prevalence, duration and associated weight and behaviour changes for specific weight loss strategies over four years in US adults

OBJECTIVES: This present study describes weight control strategies used by a heterogeneous sample of US adults and their associations with weight and behaviour change over time. DESIGN: A prospective cohort study. PARTICIPANTS: Participants for this study were 1120 US adults recruited from the community who enrolled in a three-year intervention study to examine methods for preventing age-related weight gain. MEASURES: Measured body weight and self-reported behaviours related to body weight (dieting practices, dietary intake and physical activity) were completed annually for four years. RESULTS: Over 70% reported using each of the following dieting strategies at least once in four years: increase exercise (82.2%); decrease fat intake (78.7%); reduce food amount (78.2%); and reduce calories (73.2%). Cumulative duration of use of these behaviours was brief (for example, even the most common behaviours were used only 20% of the time). Global reports of dieting were not predictive of weight change over time. However, a dose-response relationship was observed between reported duration of use of several specific weight loss strategies over the four years and change in behaviours and weight gain. CONCLUSIONS: These findings suggest that public health recommendations for weight control may need to place greater emphasis on persistence of weight control behaviours.