Effects of healthy low-carbohydrate diet and time-restricted eating on weight and gut microbiome in adults with overweight or obesity: Feeding RCTOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study tested whether a healthy low-carbohydrate diet (HLCD) and time-restricted eating (TRE), alone or combined, affect body weight and the gut microbiome beyond what caloric restriction alone produces. It used a 12-week two-by-two factorial randomized controlled feeding trial with a 28-week follow-up period. The design let researchers isolate the added effects of carbohydrate restriction and eating-window timing on top of isocaloric-restricted feeding.
Who was studied?
The trial enrolled 96 participants with overweight or obesity. Participants were assigned across the two-by-two factorial design to receive isocaloric-restricted feeding with or without HLCD and with or without TRE. The abstract does not give further demographic detail such as age or sex distribution.
What were the most important findings?
Isocaloric-restricted feeding produced significant weight loss ranging from 2.57 to 4.11 kg across groups, and both HLCD and TRE produced additional reductions in body mass index beyond caloric restriction alone. HLCD led to additional fat mass loss, while TRE led to more lean mass loss, showing the two strategies affect body composition differently. HLCD also decreased fecal branched-chain amino acids, and TRE tended to increase the abundance of probiotic species that synthesize short-chain fatty acids. The fat-mass-reducing effect of HLCD persisted through the post-intervention follow-up period.
What are the greatest implications of this study?
The findings suggest that dietary carbohydrate composition and meal timing each add measurable value to weight management beyond simple calorie counting. HLCD and TRE produce distinct effects on body composition (fat versus lean mass) and distinct, profound alterations to the gut microbiome and metabolome. The persistence of HLCD's fat-loss effect after the intervention ended points to potential durability of low-carbohydrate approaches. These results support tailoring weight-management strategies to specific metabolic and microbiome-related goals rather than treating all caloric-restriction approaches as equivalent.