Water and sugar-sweetened beverage consumption and changes in BMI among Brazilian fourth graders after 1-year follow-up.

OBJECTIVE We examined whether drinking water per se is associated with drinking less of other beverages and whether changes in BMI are associated with the intake of water and other beverages. DESIGN Secondary analysis of a randomized trial of fourth graders followed over 1 year. SETTING Public schools in the metropolitan area of Rio de Janeiro, Brazil. SUBJECTS Participants were 1134 students aged 10-11 years. RESULTS At baseline, a higher frequency of water consumption was associated with a greater daily intake of fruit juice (P = 0.02) and a higher daily frequency of milk (P = 0.005). In the intervention group, the baseline frequency of water consumption was negatively associated with weight change over 1 year but without statistical significance (coefficient = -0.08 kg/m2; 95 % CI -0.37, 0.24 kg/m2), whereas fruit juice intake frequency was positively associated with weight change: each increase in fruit juice intake of 1 glass/d was associated with a BMI increase of 0.16 (95 % CI 0.02, 0.30) kg/m2. CONCLUSIONS Our findings do not support a protective effect of water consumption on BMI, but confirm consumption of juice drinks as a risk factor for BMI gain. Students who reported high water consumption also reported high intake of other beverages; therefore, the promotion of water consumption per se would not prevent excessive weight gain.