Metabolic Effects of Late Dinner in Healthy Volunteers-A Randomized Crossover Clinical Trial.
Level 2 - randomized trial
Randomized crossover clinical trial in humans
PubMed 32525525 · doi:10.1210/clinem/dgaa354
What was done
Twenty healthy volunteers (10 male, 10 female; age 26.0 ± 0.6 years, BMI 23.2 ± 0.7 kg/m²) participated in a randomized crossover trial comparing a late dinner (LD, 22:00) with a routine dinner (RD, 18:00) in a laboratory setting with a fixed sleep window (23:00–07:00). Both visits used an identical isocaloric macronutrient diet with dinner accounting for 35% of daily calories (50% carbohydrate, 35% fat) accompanied by an oral lipid tracer ([2H31] palmitate, 15 mg/kg). Hourly nocturnal and next-morning plasma glucose, insulin, triglycerides, free fatty acids, cortisol, dietary fatty acid oxidation, and polysomnography were evaluated.
What was found
The abstract reports directional changes without numerical effect sizes or confidence intervals. Relative to routine dinner, late dinner shifted the postprandial window into the sleep phase and was characterized by higher glucose, a delayed triglyceride peak, lower free fatty acids, lower dietary fatty acid oxidation, and increased plasma cortisol. Sleep architecture was unaffected. These metabolic changes were most pronounced in habitual earlier sleepers.
Why it matters
This trial demonstrates that shifting dinner closer to bedtime acutely induces nocturnal glucose intolerance and suppresses lipid oxidation during sleep, providing a physiological mechanism for the observed associations between late eating, obesity, and metabolic syndrome.
Limits
The study had a small sample size (n = 20) of young, healthy, normal-weight individuals, limiting generalizability to older or metabolically impaired populations. The trial tested acute single-night responses under laboratory conditions rather than sustained habitual late dinner patterns. Quantitative values and effect sizes are not reported in the abstract.
Cited by
- supports Eating identical meals later in the day reduces fat oxidation compared to consuming those meals earlier in the day within the same duration eating window.