Longitudinal effect of nutritional intervention on body weight: A randomized controlled trial.

Abstract Objectives: This study evaluates, in the medium and long term (12, 36, and 48 mo), the effect of an intervention to promote consumption of fruit and vegetables on the body weight of Brazilian primary health care users. Methods: A follow-up with participants (n = 3414) in a controlled randomized trial was performed in a primary health care service. Those in the control group performed the service's usual intervention (guided physical exercise 3 times/wk), and those in the intervention group additionally participated for 7 mo in collective activities to promote consumption of fruit and vegetables. Sociodemographic, health, and body weight data were collected by face-to-face interview at baseline and after 12 mo. At 36 and 48 mo, weight was obtained by telephone interview and was validated. Adherence to the intervention was assessed by the presence of the actions. Weight change (Δ) was measured by subtracting the weight at each follow-up time from the baseline measurement. Results: Participants in both groups had a minor weight loss of about 0.1 kg over 12, 36, and 48 mo. The addition of an intervention for consumption of fruit and vegetables did not enhance this effect. Higher weight loss was observed in individuals with obesity classes II and III with low adherence in the intervention and after 36 mo (Δ = −27.1 kg; P = 0.024). Conclusions: Participating in the primary health care service contributed to a small reduction in weight, and the intervention for consumption of fruit and vegetables did not enhance this effect. However, greater weight loss was observed in participants with obesity and those who adhered to the intervention.