Longevity & Aging · Metabolic & Cardiometabolic
periodic fasting-mimicking diet FMD cycles improves cardiometabolic biomarkers weight BP IGF-1 glucose lipids CRP in humans
In plain terms: Do a few days of a low-calorie fasting-mimicking diet each month actually improve blood-sugar, blood-pressure and cholesterol markers?
Part of: • Fasting & Time-Restricted Eating
Yes, small RCTs mostly Longo's own network show modest short-term improvements, but they largely overlap with plain calorie restriction/weight loss and independent replication is thin.
📅 Last reviewed: 2026-07-14 ⓘ
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: Human trials (RCT / n-of-1)
How the studies fall
What the evidence shows
Small randomised trials show fasting-mimicking cycles modestly improving glucose, insulin resistance and inflammatory markers, including a monthly protocol reducing faecal calprotectin in Crohn's disease and a 12-month trial cutting medication need in type 2 diabetes. Most come from the originating network, the trials are small, and the benefits largely overlap with weight loss.
The evidence (12)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Espinoza SE, Park S, Connolly G, Qi W, Zhang N, Semwal M, Li Y, Lauzon M, Salmon AB, Hsu W, Wei M, Musi N 2025 · GeroScience | RCT | supports | low | Pilot RCT found FMD improved fasting glucose, HOMA-IR, BHB and autophagic flux in healthy adults, though effects were not significant across all timepoints and it was industry-sponsored. |
| Sulaj A, Nguyen PBH, Poschet G, Kliemank E, Fleming T, Henke L, Neibig W, Kopf S, Hell R, Longo VD, Herzig S, Nawroth PP, Menden MP, Szendroedi J 2025 · Mol Metab | observational | mixed | low | 6-month periodic fasting (FMD-type) regimen restored metabolic flexibility and improved albuminuria in type 2 diabetes, with accompanying metabolic improvements. |
| Kulkarni C, Fardeen T, Gubatan J, Ye J, Jarr K, Dickson E, Jang H, Temby M, Patel A, Jiang Y, Singh G, Keyashian K, Streett S, Ho E, Barber G, Singh S, Limsui D, Anaizi N, Becker L, Spencer SP, Mehrish D, Perelman D, Longo VD, Charu V, Ashouri JF, Davis MM, Habtezion A, Sonnenburg JL, Gardner C, Sinha SR 2026 · Nat Med | RCT | mixed | moderate | RCT of monthly 5-day FMD cycles in Crohn's disease showed reduced inflammation (fecal calprotectin) and clinical response, though endpoints were disease-activity rather than classic cardiometabolic markers. |
| Andriessen C, Fealy CE, Veelen A, van Beek SMM, Roumans KHM, Connell NJ, Mevenkamp J, Moonen-Kornips E, Havekes B, Schrauwen-Hinderling VB, Hoeks J, Schrauwen P 2022 · Diabetologia | RCT | mixed | moderate | Independent (Schrauwen group) crossover RCT of a related fasting protocol (TRE) in T2D: improved glucose homeostasis but did NOT improve insulin sensitivity — partial, non-FMD replication of benefit with a null on a key mechanism. |
| Siavoshi F, Smith MD, Cassard S, Moreau GB, Brenton JN, Mowry EM, Fitzgerald KC, Bhargava P 2025 · Ann Neurol | RCT | mixed | moderate | Secondary analysis of fasting-mimicking/calorie-restriction diets reduced metabolomic age in multiple sclerosis, but daily calorie reduction had no effect, indicating benefits are protocol-dependent. |
| Brandhorst S, Levine ME, Wei M, Shelehchi M, Morgan TE, Nayak KS, Dorff T, Hong K, Crimmins EM, Cohen P, Longo VD 2024 · Nat Commun | RCT | supports | low | Human secondary/exploratory analysis of Longo-lab RCTs: 3 FMD cycles lowered insulin resistance, pre-diabetes markers and hepatic fat; Longo-lab, exploratory. |
| Micarelli A, Mrakic-Sposta S, Vezzoli A, Malacrida S, Caputo S, Micarelli B, Misici I, Carbini V, Iennaco I, Granito I, Longo VD, Alessandrini M 2025 · Cell Rep Med | RCT | supports | moderate | Human 102-subject cross-over RCT: 6 monthly FMD cycles reduced cardiometabolic/inflammatory markers and diabetic drug use; Longo is a co-author (not fully independent). |
| van den Burg EL, Schoonakker MP, van Peet PG, van den Akker-van Marle EM, Lamb HJ, Longo VD, Numans ME, Pijl H 2024 · Diabetologia | RCT | supports | moderate | RE-HOMED 2026-10-04 from claim-fmd-reduces-biological-age, where it was off-scope because it measures no biological-age endpoint; these ARE its endpoints. 12-month randomised, assessor-blinded trial, 100 adults with type 2 diabetes on metformin and/or diet, monthly 5-day FMD cycles as an adjunct to usual primary care vs usual care alone. Adjusted treatment effects at 12 months: medication effect score -0.3 (95% CI -0.4, -0.2; p<0.001), HbA1c -3.2 mmol/mol (-6.2, -0.2; -0.3%, p=0.04), body weight -3.6 kg (-5.2, -2.1; p<0.001); glycaemic management improved in 53% of FMD vs 8% of control and deteriorated in 23% vs 59% (p<0.001). Limits on quality: assessor-blinded rather than double-blind (an unblindable diet), 18 of 100 lost to follow-up, and Longo is an author, so this is not an independent-of-the-originator trial. |
| Gabriel S, Ncube M, Zeiler E, Thompson N, Karlsen MC, Goldman DM, Glavas Z, Beauchesne A, Scharf E, Goldhamer AC, Myers TR 2022 · Nutrients | observational | mixed | low | Independent single-arm water-fast+refeed study: cardiometabolic markers improved at follow-up but triglycerides/HOMA-IR transiently WORSENED at end-of-refeed — shows fasting-family benefits are real but track weight loss and have transient adverse phases. |
| Tavakoli A, Bideshki MV, Zamani P, Tavakoli F, Dehghan P, Gargari BP 2025 · J Health Popul Nutr | meta-analysis | mixed | moderate | GRADE-assessed meta-analysis of fasting regimens found beneficial shifts in weight-regulating hormones but no effect on resistin and called for long-term data. |
| Schoonakker MP, van den Burg EL, van Peet PG, le Cessie S, Penny E, Numans ME, Pijl H, Lamb HJ 2025 · Nutr Metab Cardiovasc Dis | RCT | supports | moderate | FMD programme alongside usual care reduced abdominal visceral fat while preserving muscle in type 2 diabetes, supporting cardiometabolic benefit. |
| Burns L, Cooper S, Sarmad S, Funke G, Di Mauro A, Gaitanos GC, Tsintzas K 2025 · Clin Nutr | RCT | supports | moderate | Randomized parallel-group 7-day FMD improved cardiometabolic markers and autophagy signals versus non-intervention control in healthy humans. |
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Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.