Eight-hour time-restricted eating does not lower daily myofibrillar protein synthesis rates: A randomized control trial.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 36546330 · doi:10.1002/oby.23637
What was done
Eighteen healthy males with overweight or obesity (age 46 ± 5 years, BMI 30 ± 2 kg/m²) completed a 10-day parallel randomized trial following a 3-day lead-in diet. Participants consumed an isoenergetic diet (~1.0 g protein/kg/day) within either an 8-hour time-restricted eating window (TRE; 10:00 a.m. to 6:00 p.m.) or a 12-hour extended eating control window (CON; 8:00 a.m. to 8:00 p.m.). Daily integrated myofibrillar protein synthesis (MyoPS) was measured using deuterated water with saliva, blood, and muscle sampling. Secondary outcomes included continuous glucose monitoring and body composition by DXA.
What was found
Daily integrated MyoPS rates did not differ between groups (TRE: 1.28% ± 0.18%/day vs. CON: 1.26% ± 0.22%/day; p = 0.82). The 24-hour glucose area under the curve decreased significantly with TRE compared to CON (-578 ± 271 vs. 12 ± 272 mmol/L × 24 hours; p = 0.001). Total body mass declined in both groups (TRE: -1.6 ± 0.9 kg, CON: -1.1 ± 0.7 kg; between-group p = 0.22), but lean mass loss was significantly greater in the TRE group (-1.0 ± 0.7 kg vs. -0.2 ± 0.5 kg; p = 0.01).
Why it matters
These findings suggest that condensing daily protein intake into an 8-hour window does not impair basal muscle protein synthesis rates under energy-matched conditions, although the mechanism behind observed short-term lean mass reductions requires clarification.
Limits
The sample size was very small (n = 18) and limited entirely to middle-aged males with overweight or obesity. The intervention duration was short (10 days), dietary intake was tightly controlled rather than free-living, and resistance training was not evaluated.
Cited by
- supports A deuterated water study showed no difference in muscle protein synthesis or fat loss between time-restricted eating and non-time-restricted eating.