Intermittent Fasting

Metabolic Benefits

• Fasting insulin reduction: 20-31%
• LDL cholesterol: 5-15% reduction
• CRP: 5-40% reduction
• Improved insulin sensitivity

Autophagy

• mTOR inhibition begins at 12-16 h of fasting
• Autophagy peaks at 24-48 h
• Enhanced cellular cleanup and quality control

Protocols

• 16:8 (16 h fast, 8 h eating window)
• 5:2 (two non-consecutive low-calorie days/week)

Two-days-per-week severe deficit vs continuous restriction (weight-loss equivalence trial)

Harvie et al. 2011 (Int J Obes; PMID 20921964; harvie-2011-ier-vs-cer-weight-loss-metabolic-randomized-ijo) randomised premenopausal women to ~25% total energy deficit as intermittent (~2710 kJ/day on 2 days/week) vs continuous daily restriction—similar mean weight loss over 6 months in LOCF models (P = 0.4) with modestly larger fasting insulin / HOMA-IR improvements on the intermittent template (P = 0.04 between groups); not identical to modern 16:8 apps—read arms before generalising.

MASLD-focused IF network meta-analysis (liver-imaging endpoints)

Abuelazm et al. 2024 (Eur J Gastroenterol Hepatol; PMID 38407890; abuelazm-2024-if-masld-network-meta-ejgh) network-meta-analysed 8 RCTs (n = 635) with MASLD: 5:2 schedules improved liver stiffness, time-restricted feeding improved CAP steatosis scores, and alternate-day fasting moved anthropometrics in abstract-reported contrasts—liver enzymes / lipids / HOMA-IR often null across templates; do not substitute for hepatology care plans.

Periodic fasting-mimicking diet (not the same as daily 16:8 windows)

Wei et al. 2017 (Sci Transl Med; PMID 28202779; wei-2017-fasting-mimicking-diet-risk-markers-sci-transl-med) randomised generally healthy adults to three 5-day fasting-mimicking diet cycles versus control over 3 months—reporting reductions in weight, trunk/total body fat, blood pressure, and IGF-1, with larger marker shifts in a higher baseline-risk subgroup in post hoc analyses. This is a short-cycle, low-calorie formulated pattern—interpret separately from 16:8 adherence trials and TRE isocaloric crossover work on time-restricted-eating.

Meal timing without intended weight loss (crossover anchor)

Sutton et al. 2018 (Cell Metab; PMID 29754952): supervised early 6 h feeding vs 12 h control in prediabetic men with weight held stable—reported insulin sensitivity, β-cell responsiveness, morning blood pressure, 8-isoprostane, and appetite signals favoring early consolidation; full methods and figures on the linked source row (also filed under Time-restricted eating).

Pooled TRE vs caloric-match controls (body composition)

Fernandes-Alves et al. 2025/2026 (Nutr Rev; PMID 40298934; fernandes-alves-2025-tre-caloric-restriction-ma) pools 30 window-eating RCTs in overweight/obesity with separate isocaloric and non-isocaloric comparator strata—mean-difference weight / fat / lean-mass estimates and PROSPERO registration on the linked row; scheduling context stays on Time-restricted eating (time-restricted-eating).

Related registry

Daily eating-window controlled trials (including other 8–10 h windows and reviews) are curated under Time-restricted eating (time-restricted-eating).

GLP-1 receptor agonist therapy (glp-1-receptor-agonist-therapy) indexes prescription incretin drugs—a different lever from voluntary fasting schedules; keep evidence streams separate.

Tertiary map

Wikipedia: Intermittent fasting (wikipedia-intermittent-fasting-overview), Wikipedia: Autophagy (wikipedia-autophagy-overview), and Wikipedia: Chrononutrition (wikipedia-chrononutrition-overview) map IF branding, mTOR/autophagy mechanism prose, and clock-aligned nutrition vocabulary—pooled weight / fat / lean-mass MDs and glycemic endpoints remain on PubMed-linked rows (including fernandes-alves-2025-tre-caloric-restriction-ma shared with Time-restricted eating).