Consuming 6.8 grams of psyllium before breakfast and lunch for three days resulted in significantly lower scores on the VAS Desire to Eat Scale and the VAS Hunger Scale post-breakfast and post-lunch.
“It is reasonable to hypothesize that the effect of dietary psyllium fiber supplementation on satiety might be useful in weight management,” wrote the researchers in the journal Appetite. “[T]he complexities involved in mechanisms of body weight control involves far more variables than just satiety and regarding psyllium it would need to be demonstrated through randomized trials addressing specifically the endpoint of weight loss.
“The findings of the studies in this report indicate that psyllium has a satiety effect but further investigation is necessary to determine its clinical relevance as a tool to promote decreased energy intake and weight control.”
Scientists from Procter & Gamble Personal Health Care, the University of Colorado, and Purdue University performed two studies: The first one was to determine an optimal dose, and they performed a randomized, double-blind, placebo-controlled cross-over study using 3.4 g, 6.8 g, and 10.2 g of psyllium. Participants consumed these doses before breakfast and lunch for 3 days.
The first study indicated that greater reductions in in hunger and desire to eat were obtained for the two higher doses, compared to the 3.4 gram dose, but there were no differences between the 6.8 and 10.2 doses.
A second study used the 6.8 gram determined in the first study. Participants consumed the psyllium dose before breakfast and lunch for two days, and then only before breakfast on the third day. The breakfast had lower calorie levels (energy restricted) than observed in the first study.
Results of the second study indicated that satiety measures were similarly to the first study, despite having an energy restricted breakfast.
“Dietary fiber affects satiety in many ways, depending on the fiber type, and relating to its ability to bulk foods, increase viscosity, gel in the stomach and ferment in the gut,” explained the researchers. “Psyllium is a soluble viscous fiber that has the ability to gel in the stomach. Both aspects are important for the efficacy of psyllium.
“[G]el-forming fibers (such as psyllium) may influence satiety by several mechanisms, including delayed degradation and absorption of nutrients in the small bowel, leading to a ‘sustained’ delivery of nutrients; and delivery of nutrients to the distal ileum with subsequent stimulation of feedback mechanisms like the ‘ileal brake’ phenomenon (slows gastric emptying and small bowel transit) and decreased appetite. These proposed mechanisms involve the participation of gut hormones and the central nervous system favoring higher sensations of satiety.”
The researchers also considered potential adverse events among the participants, and found that most were mild gastrointestinal symptoms and were similar between psyllium groups and placebo.
Volume 105, Pages 27–36, doi: 10.1016/j.appet.2016.04.041
“Satiety effects of psyllium in healthy volunteers”
Authors: J.M. Brum, et al.