Energy density of foods affects energy intake across multiple levels of fat content in lean and obese women

Background: The results of previous studies indicated that energy density, independent of fat content, influences energy intake. In most studies, howe ver, both fat content and energy density were lower than in typical America n diets. Objective: We examined the influence of energy density on intake when fat c ontent was above, below, or similar to the amount of fat typically consumed and when energy density was closer to that of American diets. Design: Lean (n = 19) and obese (n = 17) women consumed all meals daily in our laboratory during 6 experimental sessions. The main entrees, consumed a d libitum, were formulated to vary in fat content (25%, 35%, and 45% of ene rgy) and energy density (5.23 kJ/g, or low energy density, and 7.32 kJ/g, o r high energy density) but to have similar palatability. Results: Energy density influenced energy intake across all fat contents in both lean and obese women (P < 0.0001). Women consumed less energy in the low (7531 kJ) than in the high (9414 kJ) energy density condition. Despite this 20% lower energy intake, there were only small differences in hunger ( 7%) and fullness (5%). Women consumed a similar volume, but not weight, of food daily across conditions. Differences in intake by weight, but not volu me, occurred because for some versions of manipulated foods, weight and vol ume were not directly proportional. Conclusions: Energy density affected energy intake across different fat con tents and at levels of energy density comparable with those in typical diet s. Furthermore, our findings suggest that cues related to the amount of foo d consumed have a greater influence on short-term intake than does the amou nt of energy consumed.