No apparent effects of a viscous, superabsorbent hydrogel on appetite, energy intake, or fecal excretion in overweight adults

As the obesity epidemic continues, there is a great need for safe and effective weight loss aids. A superabsorbent hydrogel device administered as a capsule demonstrates potential for weight loss, but its mechanism of action remains unclear. The present study's goal was to determine the mechanisms of action of the hydrogel through the investigation of its effects on appetitive sensations, eating behavior, energy intake, and fecal excretion of energy. Overweight and obese adults (n = 18) participated in a double-blind, randomized, crossover-design study in which they were provided all meals for a week in a supervised setting (i.e., controlled-feeding) and were required to either consume the hydrogel or a placebo with 16-oz of water 20 min before lunch and dinner. No differences in appetite (all, p > 0.05), total fecal nitrogen excretion (p = 0.74), total fecal fat excretion (p = 0.54), or total fecal energy excretion (p = 0.76) were identified when comparing the hydrogel to a placebo. Affect towards food (i.e., mood, emotions) was more positive in the hydrogel group compared with the placebo group. A subset of the controlled-feeding group (n = 10) then participated in another double-blind, randomized, crossover-design study in which they provided their own food for a week (i.e., free-feeding) and were required to either consume the hydrogel or a placebo with 16-oz of water 20 min before lunch and dinner. No differences in appetite (all, p > 0.05), energy intake (p = 0.95), diet quality (all, p > 0.05), or eating behavior (all, p > 0.05) were determined when comparing the hydrogel to the placebo. Future studies with greater statistical power should confirm these findings and investigate other potential mechanisms of action of the hydrogel.