Eating behavior in Prader-Willi syndrome, normal weight, and obese controlgroups

Objective: Hyperphagia in Prader-Willi syndrome (PWS) is hypothesized to be due to hypothalamic dysfunction; thus the study of individuals with PWS mi ght illustrate how hypothalamic dysfunction affects eating behavior. The ai m of this study was to document the microstructure of the eating behavior i n patients with PWS and to compare it with that of members of obese and nor mal weight control groups of the same age. Study design: Nine subjects with PWS (age, 10 +/- 4 years), 20 normal weigh t subjects (age, 12 +/- 3 years), and 20 obese subjects (age, 12 +/- 4 year s) were served an e.ucess lunch meal (hash) on a hidden scale built into a table and connected to a computer. The plate of food is placed on top of th e scale, and when the food is eaten, the change in food weight is registere d continuously. An eating curve is displayed online. After the meal, the ea ting data are fitted to a polynomial, and the computer calculates the amoun t of food eaten, time of consumption, eating rate (initial and total), and rate of deceleration. Results: Subjects with PWS were found to halle a longer duration of eating (P =.04) and a slower initial eating rate (P =.01) compared with members of both obese and normal weight groups. In subjects with PWS, 56% of the eati ng curves were non-decelerating (linear or accelerating) compared with 10%, of the normal weight group and 30% of the obese group (P =.02). Conclusion: The microstructure of the eating behavior in subjects with PWS differs from that of members of obese and normal weight control groups. Thu s the eating behavior found in subjects with PWS might be due to decreased satiation rather than increased hunger.