Effect of alginate supplementation on weight loss in obese subjects completing a 12-wk energy-restricted diet: a randomized controlled trial¹²³

Background: Acute studies with alginate-based preloads suggested that these strong gelling fibers may induce increased feelings of satiety and reduce energy intakes. However, the long-term efficacy and safety of alginate supplementation on body weight regulation are lacking.

Objective: The primary aim of the study was to investigate the effects in subjects of alginate supplementation in conjunction with energy restriction (−300 kcal/d) on loss of body weight and fat and, second, on metabolic risk markers in comparison with in a placebo group.

Design: In a parallel, double-blind, placebo-controlled study, we randomly assigned 96 obese subjects to either an energy-restricted diet plus a placebo preload supplement or an energy-restricted diet plus an alginate-based preload supplement (15 g fiber). The preload was administered as a beverage 3 times/d before main meals for a period of 12 wk.

Results: No differences in loss of body weight and fat between groups were shown in the intension-to-treat (ITT) analysis (P > 0.1). However, in the completer analysis (n = 80), we showed a greater weight loss with alginate (6.78 ± 3.67 kg) than with the placebo (5.04 ± 3.40 kg) (P = 0.03), which was mainly attributed to a reduction in the percentage of body fat (P = 0.03). In the ITT analysis, a larger decrease in systolic and diastolic blood pressure was shown in the placebo group than in the alginate group (P < 0.05). Plasma concentrations of glucose, insulin, C-reactive protein, and ghrelin, HOMA-IR, and lipid metabolism did not differ between treatment groups in the ITT analysis (P > 0.1).

Conclusion: These results suggest that alginate supplementation as an adjunct to energy restriction may improve weight loss in obese subjects who complete a 12-wk dietary intervention. This trial was registered at clinicaltrials.gov as NCT01231178.