Water incorporated into a food but not served with a food decreases energy intake in lean women

Background: Previous research showed that decreasing the energy density (kJ/g) of foods by adding water to them can lead to reductions in energy intake. Few studies have examined how water consumed as a beverage affects food intake. Objective: This study examined the effects of water, both served with a food and incorporated into a food, on satiety. Design: In a within-subjects design, 24 lean women consumed breakfast, lunch, and dinner in our laboratory 1 d/wk for 4 wk. Subjects received 1 of 3 isoenergetic (1128 kJ) preloads 17 min before lunch on 3 d and no preload on 1 d. The preloads consisted of 1) chicken rice casserole, 2) chicken rice casserole served with a glass of water (356 g), and 3) chicken rice soup. The soup contained the same ingredients (type and amount) as the casserole that was served with water. Results: Decreasing the energy density of and increasing the volume of the preload by adding water to it significantly increased fullness and reduced hunger and subsequent energy intake at lunch. The equivalent amount of water served as a beverage with a food did not affect satiety. Energy intake at lunch was 1209 [+ or -] 125 kJ after the soup compared with 1657 [+ or -] 148 and 1639 [+ or -] 148 kJ after the casserole with and without water, respectively. Subjects did not compensate at dinner for this reduction in lunch intake. Conclusion: Consuming foods with a high water content more effectively reduced subsequent energy intake than did drinking water with food. Am J Clin Nutr 1999;70:448-55.