Skip to main content
NUTRITION 2025 Main banner

Late Breaking/Rapid Science Oral Session

(LB04-03-25) Chronotype-Adapted Dietary Intervention Enhances Weight Loss, Metabolic Health, and Gut Microbiota in Overweight/Obese Individuals: The CHRONODIET Randomized Trial

Sunday, June 1, 2025
2:24 PM – 2:36 PM ET
Location: S230 CD
Objectives: Emerging evidence suggests that aligning dietary patterns with an individual’s circadian rhythm, or chronotype, may optimize metabolic processes and gut microbiota (GM) composition and function. Given the burden of obesity, a chronotype-adapted diet – aligning meal timing with biological rhythms – could be an innovative approach to weight management. This study is the first to investigate whether a chronotype-adapted diet is more effective than a conventional calorie-distributed diet in promoting weight loss and improving cardiometabolic risk factors and GM.

Methods: In this 4-month, open-label, randomized controlled trial, 140 overweight/obese adults were assigned to either a chronotype-adapted, low-calorie diet with meal timing tailored to their metabolic peaks (morning vs. evening chronotype) or a standardized low-calorie eating plan. The primary outcome was weight change. Secondary outcomes were changes in body composition, biochemical markers, GM composition, and short-chain fatty acids (SCFAs).

Results: A total of 117 participants (84%; mean age 49±12 years) completed the study (57 intervention, 60 control). While both groups experienced significant weight loss (p < 0.05), reductions were greater in evening chronotypes (-3.7 kg) compared to morning chronotypes (-3.2 kg) and controls (-2.5 kg). Fat mass percentage decreased significantly in the intervention group (-2.8% in evening and -1.6% in morning chronotypes), while the control group showed no significant change (-0.5%). Both groups exhibited reductions in total and LDL cholesterol, but only morning chronotypes showed a significant glucose decrease (-2.9 mg/dL). GM analysis revealed an enrichment of SCFA-producing bacteria, such as Clostridiales vadin BB60, and a reduction in Nitrososphaeraceae in the intervention group, accompanied by increased production of anti-inflammatory SCFAs compared to controls (isobutyric acid: +0.42% vs. -0.25%; 2-methylbutyric acid: +0.43% vs. -0.44%).

Conclusions: A chronotype-adapted diet may be more effective than a standard low-calorie diet in improving body composition, metabolic risk profile, and gut microbiota in overweight/obese individuals – particularly among evening chronotypes, who may face greater challenges with conventional dietary strategies.

Funding Sources: This research received no specific grant.