Effects of food form on appetite and energy intake in lean and obese young adults

Abstract
To investigate the independent effect of food form on appetite and energy intake in lean and obese adults using high carbohydrate, fat or protein food stimuli. Crossover dietary challenge with matched beverage and solid food forms: high carbohydrate (watermelon and watermelon juice); high protein (cheese and milk); high fat (coconut meat and coconut milk). A total of 120 lean (18-23 kg/m(2); N=60) and obese (30-35 kg/m(2); N=60) adults (18-50 years old) with stable body weight. Forty different participants (N=20 lean and 20 obese) were tested with each of the food systems. Appetitive sensations, food palatability and dietary intake. Regardless of the predominant energy source, the beverage food form elicited a weaker compensatory dietary response than the matched solid food form. Thus, total daily energy intake was significantly higher by 12.4, 19 and 15% on days the beverage forms of the high-carbohydrate, -fat and -protein foods were ingested, respectively. This was due more to a weak effect on satiety than satiation. The obese participants had higher energy intake at the lunch, including the beverage high-protein load, but overall differences between lean and obese participants were small and not systematic. Food rheology exerts an independent effect on energy intake. Dietary compensation for beverages is weaker than for solid food forms of comparable nutrient content. Thus, they pose a greater risk for promoting positive energy balance.