Evidence mapPaperPMID 42463249Full record

ArticleAdvances in nutrition (Bethesda, Md.)2026

Intermittent Fasting and Fat-Free Mass Outcomes in Middle-Aged and Older Adults: A Scoping Review.

Sara Santero, Bojana D Blagojević, Mohammed Merzah, José Antonio Celada Guerrero, Hellas Cena, José Maria Ordovas, Lidia Daimiel Ruiz

Abstract readScoping Review
In one paragraph

Article in Advances in nutrition (Bethesda, Md.), 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Sara SanteroLaboratory of Dietetics and Clinical Nutrition, Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Pavia, Italy.
Bojana D BlagojevićUniversity of Novi Sad, Faculty of Agriculture, From Farm to Pharm Group, Nutriomics Lab, Novi Sad, Serbia.
Mohammed MerzahDepartment of Public Health and Epidemiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary; Department of Community Health Techniques, Polytechnic College - Karbala, Al-Furat Al-Awsat Technical University, Kufa, Iraq.
José Antonio Celada GuerreroNutritional Control of the Epigenome Group, Precision Nutrition and Obesity Program, IMDEA Nutrition, UAM + CSIC, Madrid, Spain.
Hellas CenaLaboratory of Dietetics and Clinical Nutrition, Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Pavia, Italy; Istituti Clinici Scientifici Maugeri IRCCS, Unit of Clinical Nutrition, Pavia, Italy.
José Maria OrdovasNutritional Control of the Epigenome Group, Precision Nutrition and Obesity Program, IMDEA Nutrition, UAM + CSIC, Madrid, Spain; Nutrition and Genomics Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, United States; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y la Nutrición, Institute of Health Carlos III, Madrid, Spain.
Lidia Daimiel RuizNutritional Control of the Epigenome Group, Precision Nutrition and Obesity Program, IMDEA Nutrition, UAM + CSIC, Madrid, Spain; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y la Nutrición, Institute of Health Carlos III, Madrid, Spain. Electronic address: lidia.daimiel@nutricion.imdea.org.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Intermittent fasting (IF) has gained popularity as a weight-loss strategy. Because muscle mass naturally declines with age, concerns arise about effects on fat-free mass (FFM) in aging populations. The objective of this review was to explore the current evidence on the effects of IF on: 1) FFM in middle-aged and older adults, compared with habitual diet (HD) or continuous energy restriction (CER); and 2) other anthropometric outcomes, functional performance, and quality of life. Three databases were searched, supplemented with snowballing and the clinicaltrials.gov registry. Eligible studies (2000-2025) were randomized controlled trial (RCTs) in adults ≥45 y, with IF lasting ≥4 wk, reporting FFM using validated methods, and excluding participants with disease-related muscle loss. Twenty RCTs (1653 participants; 64% females), primarily involving adults with overweight/obesity, were included. Over the intervention durations studied (commonly ≤12 wk), between-group differences in total FFM were generally small. Findings showed that IF produced reductions in fat mass (FM), body weight (BW), and waist circumference that were comparable with those observed with CER. Reductions in BW and FM were more consistently reported in IF compared with HD. Alternate-day fasting and alternate-day modified fasting were commonly studied and frequently associated with BW and FM reductions, particularly compared with HD. Evidence regarding insulin-related outcomes, dietary protein intake, and combined IF and physical activity interventions was limited and heterogeneous. Functional and quality of life outcomes were rarely assessed. Most studies measured total FFM or lean mass using dual-energy X-ray absorptiometry or bioelectrical impedance analysis; thus, it may not reflect skeletal muscle changes. Collectively, the current evidence does not permit definitive conclusions regarding the impact of IF on FFM preservation, especially in the long-term, in older populations. The findings highlight substantial gaps in study duration and methodological standardization. Longer-term, high-quality trials incorporating standardized muscle health and functional outcomes are needed to clarify the role of IF in strategies for healthy aging.

Indexed as

Body CompositionIntermittent FastingAgedCaloric RestrictionFemaleHumansMaleMiddle AgedObesityOverweightQuality of LifeRandomized Controlled Trials as TopicWeight Lossalternate-day fastingbody compositionfastingfat-free massintermittent fastingmiddle-aged adultsmuscle massolder adultstime-restricted eating

Identifiers

PMID42463249
PMCPMC13390093

What Socratic holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.