St-Onge · Obesity (Silver Spring, Md.) 2012 · double-blind, placebo-controlled randomized trial · n=60

A weight-loss diet including coffee-derived mannooligosaccharides enhances adipose tissue loss in overweight men but not women.

Level 2 - randomized trial

Individual randomized controlled trial

PubMed 21938072 · doi:10.1038/oby.2011.289 · record verified 2026-08-26

What was done

A 12-week, double-blind, placebo-controlled randomized trial evaluated the effect of coffee-derived mannooligosaccharides (MOS; 4 g/day) on weight and fat loss during an energy-restricted diet. Sixty overweight men and women were assigned to consume either MOS or placebo beverages alongside weekly group counseling; 54 participants completed the protocol. Primary outcomes included weekly weight and blood pressure measurements, and baseline to 12-week changes in adipose tissue compartments assessed via magnetic resonance imaging (MRI).

What was found

In men, the MOS group achieved significantly greater total body weight loss compared to the placebo group (-6.0 ± 0.6% vs. -2.3 ± 0.5%, P < 0.05). Men receiving MOS also showed significantly greater reductions than placebo in total body volume (P < 0.0001), total adipose tissue (P < 0.0001), subcutaneous adipose tissue (P < 0.0001), and visceral adipose tissue (P < 0.05). In women, there were no statistically significant differences between MOS and placebo for weight loss or any measured adipose tissue compartment.

Why it matters

Coffee-derived MOS may serve as a functional dietary adjunct to accelerate total and visceral fat reduction during caloric restriction, although its efficacy appears restricted to men.

Limits

The study had a small sample size (60 enrolled, 54 completed) and a relatively short 12-week duration. The abstract does not report the sex breakdown, exact numerical fat mass losses, or potential mechanisms underlying the lack of efficacy in women. Long-term weight maintenance after intervention cessation was not evaluated.