Beverage vs. solid fruits and vegetables: effects on energy intake and body weight.

Beverage consumption has been implicated in weight gain, but questions remain about the veracity of the association, whether the relationship is causal and what property of beverages is responsible. It was hypothesized that food form is the most salient attribute. Thus, a randomized controlled trial of food form was conducted. Energy-matched beverage or solid forms of fruits and vegetables were provided to 34, lean or overweight/obese adults for two 8-week periods with a 3-week washout interspersed. Dietary compensation was incomplete (beverage 53%; solid 78%) and body weight increased after the beverage (1.95 ± 0.33 kg) (77% fat mass) and solid (1.36 ± 0.30 kg) (85% fat mass) treatments (both P < 0.0005). Differences between food forms were not significant. The lean group had the highest dietary compensation (119%) and no significant weight change (0.84 ± 0.53 kg) after consuming the solid fruits and vegetables whereas the overweight/obese group had lower compensation and significant weight gain during the solid arm (46%, 1.77 ± 0.32 kg, P < 0.0001). In contrast, incomplete dietary compensation and weight gain occurred in both the lean (43%, 1.61 ± 0.44 kg, P = 0.003) and overweight/obese (61%, 2.22 ± 0.47 kg, P < 0.0005) groups during the beverage arm. Secondary analyses revealed the obese group gained more weight than the lean and overweight groups during the beverage intervention (P = 0.024). These data demonstrate energy consumed as beverages may be especially problematic for weight gain. They also indicate that advice to increase fruit and vegetable consumption should emphasize total energy intake because the additional energy contributed may promote weight gain, especially among overweight and obese individuals.