Pre-meal water consumption reduces meal energy intake in older but not younger subjects

VAN WALLEGHEN, EMILY, JEB S. ORR, CHRIS L. GENTILE, AND BRENDA M. DAVY. Pre- mealwater consumption reduces mealenergy intake in older but not younger subjects. Obesity. 2007;15:93–99. Objective: To determine whether the consumption of water 30 minutes before an ad libitum mealreduces mealenergy intake in young and older adults. Research Methods and Procedures: Healthy, non-obese young (n 29; age, 21 to 35 years) and older (n 21; age, 60 to 80 years) individuals were provided with an ad libitum lunch mealon two occasions. Thirty minutes before the lunch meals, subjects were given either a water preload (WP: 375 mL, women; 500 mL, men) or no preload (NP). Energy intake at the two lunch mealswas measured. Visual analog scales were used to assess changes in hunger, fullness, and thirstduring the mealstudies. Results: There was no significant difference in mealenergy intake between conditions in the young subjects (892 51 vs. 913 54 kcal for NP and WP, respectively; p 0.65). However, mealenergy intake after the WP was significantly reduced relative to the NP condition in the older subjects (682 53 vs. 624 56 kcal for NP and WP, respectively; p 0.02). This effect was caused primarily by the reduction in mealenergy intake after water consumption in older men. Hunger ratings were lower and fullness ratingswere higher in older compared with younger adults (p 0.01). Fullness ratingswere higher in the WP condition compared with the NP condition for all subjects (p 0.01). No age differences in thirstwere detected during the test meals. Discussion: Under acute test mealconditions, pre- mealwater consumption reduces mealenergy intake in older but not younger adults. Because older adults are at increased risk for overweight and obesity, intervention studies are needed to determine whether pre- mealwater consumption is an effective long-term weight managementstrategy for the aging population.