Effect of a cross-linked cellulose-containing weight-loss supplement on gastric emptying and sensory functions in obese subjects

Aims: CM3, a weight-loss supplement consisting of highly cross-linked cellulose, is applied in a capsule-form and expands in the stomach to a size up to 18-fold of its original. It is advertised as inducing an immediate feeling of satiety and delaying gastric emptying, thus supporting weight loss management. Its putative mechanism of action is unclear. Purpose of the study was to examine if CM3 delays gastric emptying (using the stable isotope 13C octanoic breath test) and influences subjective feelings of appetite sensations (using anchored visual analogue scales, VAS) after a standardized solid meal.

Design and methods: We investigated in a double-blind randomized placebo-controlled crossover trial 19 moderately obese but otherwise healthy subjects (7 men, 12 women; mean age 55±9yrs, body mass index 31.1±4.6kg/m²). The subjects were treated with 6 capsules of CM3 or matching placebos 30min before a standardized solid meal. Breath collection and VAS were performed over 4 hours every 15min and 30min, respectively. The analysis of the 13C fraction in the samples was performed using continuous-flow isotope ratio mass spectrometry. Half excretion time of 13CO2 in breath, indicating gastric emptying half time, was the primary outcome parameter. The maximal speed of gastric emptying was measured by the time of maximal 13CO2 excretion rate. The study was powered to detect a change in gastric emptying of 30min, which was assumed to be clinically relevant. Sample size calculation for the primary outcome parameter was calculated assuming an alpha of 0.05, a power of 0.8, and a standard deviation of the difference of 0.5 hours. Visual analogue scales were analyzed using repeated measures analysis of variance. Since sphericity could not be assumed throughout (Mauchly's test), the Huynh-Feldt epsilon corrections were used to adjust the degrees of freedom.

Results: Mean 13CO2 half excretion time changed from 2.3±0.4 to 2.4±0.33 hours (mean difference +6min, 95% CI -3 to +15min; P=0.17; Student's paired t test). Mean time of maximal 13CO2 excretion rate was increased from 1.33±0.29 to 1.45±0.22 hours (mean difference +7min, 95% CI -1 to +15min; P=0.065). Appetite sensations (hunger, satiety, fullness, prospective food consumption, desire to eat something sweet, salty, savory, or fatty) changed over time during the course of the post-prandial phase but were not influenced by CM3 (repeated measures ANOVA).

Conclusions: In obese but otherwise healthy subjects the weight-loss supplement CM3 does not delay gastric emptying in a clinically relevant manner. In addition, it does not influence subjective sensations of appetite.