Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 27737674 · doi:10.1186/s12967-016-1044-0
What was done
Thirty-four resistance-trained males were randomized to an 8-week 16/8 time-restricted feeding protocol (TRF; meals at 1 p.m., 4 p.m., and 8 p.m.) or a normal diet (ND; meals at 8 a.m., 1 p.m., and 8 p.m.) while following a standardized resistance training program. Diets were matched for energy intake (TRF: 2,826 ± 412.3 kcal/day; ND: 3,007 ± 444.7 kcal/day) and macronutrients (~53–55% carbohydrate, ~24–25% fat, ~21–22% protein). Measures included body composition via DXA, thigh and arm muscle area, maximal strength (bench press and leg press), resting energy expenditure, respiratory ratio, and endocrine, inflammatory, and lipid biomarkers.
What was found
Fat mass decreased significantly in TRF compared to ND (p = 0.0448), while fat-free mass, muscle area, and maximal strength were maintained across both groups. TRF resulted in significant decreases in testosterone (p = 0.0476), IGF-1 (p = 0.0397), total leptin (p = 0.0001; not significant after fat mass adjustment), and triiodothyronine (T3), alongside an increase in adiponectin (p < 0.0001) and a decrease in respiratory ratio. No significant changes occurred in resting energy expenditure, TSH, total cholesterol, HDL, LDL, or triglycerides. Absolute numerical values for outcome changes were not reported in the abstract.
Why it matters
This study demonstrates that a 16/8 time-restricted feeding pattern can promote fat loss while preserving muscle mass and strength during resistance training, though accompanied by decreases in anabolic and thyroid hormones.
Limits
The study is limited by a small sample size (n = 34) and an exclusively male, resistance-trained cohort, limiting generalizability to females and untrained populations. The 8-week trial duration cannot determine the long-term impact of hormonal declines (testosterone, IGF-1, T3) on muscular adaptation, and specific numeric effect sizes were omitted from the abstract.
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- contradicts Fasting and one-meal-a-day (OMAD) while weightlifting stimulates growth hormone to support and retain muscle mass.