Fluid calories and energy balance: the good, the bad, and the uncertain.

Energy-yielding fluids are a large and growing proportion of daily energy intake. The specific form and nutrient composition of fluids may hold divergent implications for energy balance. Ethanol elicits a weak compensatory dietary response, resulting in positive energy balance. However, its impact on body weight is unclear, possibly due to metabolic inefficiencies. In contrast, the weak dietary compensation for clear beverages containing other energy sources is associated with weight gain. How these beverages elude satiety mechanisms has not been studied. Soups hold higher satiating value, at least in part, due to cognitive factors. Nutrient dense beverages have been used successfully in meal replacement regimens for weight management, but due to their relatively weak satiety value, are widely consumed for weight gain and as nutrient supplements. A better understanding of the role of fluid calories in the diet is needed to improve dietary guidelines.