Is intermittent fasting better for fat loss?
What the studies we have published say — strongest evidence first. Every claim below links to the paper it came from.
In adults with prediabetes or type 2 diabetes, intermittent fasting cut body weight by 4.56 kg and lowered HbA1c, fasting glucose, cholesterol and triglycerides versus control diets, but against straightforward calorie restriction it added only modest extra weight loss and no metabolic advantage.
well supported · human dataMeta-analysis of 14 randomised trials (1,101 adults with prediabetes or type 2 diabetes); fat mass, insulin, LDL, HDL and blood pressure did not improve versus control, and versus calorie restriction there were no differences in glycaemic markers, lipids or blood pressure.
In a systematic review comparing dietary strategies for psoriasis, ketogenic and continuous calorie-restriction cohorts lost 10-25.6 kg and showed significant falls in Psoriasis Area and Severity Index scores, whereas intermittent fasting cohorts lost 0-2 kg and did not; no serious adverse effects were recorded with any approach.
preliminary · human dataA systematic review published in protocol form: it reports no number of included trials or participants, includes no head-to-head comparisons, and the authors flag heterogeneity and limited follow-up. The pattern links the amount of weight lost to skin severity rather than proving one diet beats another.
Pooling 20 randomised trials in 745 college students, high-intensity interval training beat moderate-intensity continuous training for body weight (-1.23 kg), body fat percentage (-1.21%), waist circumference (-1.33 cm) and fat mass (-0.99 kg). It did not outperform steady cardio on cholesterol, triglycerides, fasting glucose or fasting insulin.
well supported · human dataMeta-analysis of 20 RCTs, 745 healthy college students; differences are small in absolute terms, evidence quality was rated moderate to very low, and glucose and lipid outcomes were very low certainty.
In a meta-analysis of five studies, intermittent fasting reduced body weight by an average of 4.25 kg in women with PCOS, alongside improvements in BMI, insulin resistance, triglycerides, free androgens and inflammation, though total testosterone, cholesterol and waist-to-hip ratio did not change.
preliminary · human dataMeta-analysis of only five studies; the authors themselves describe the evidence as preliminary, and several hormone and lipid outcomes (total testosterone, cholesterol, AMH) showed no significant change.
An exploratory multilevel meta-analysis of 11 trials in 303 generally healthy, mostly young adults found that adding intermittent fasting, usually time-restricted eating, to resistance training produced broadly similar adaptations to resistance training alone (g = 0.09, 95% CI −0.23 to 0.40). There were no clear differences in maximal strength, local muscular endurance, hypertrophy-related outcomes or explosive and high-speed performance.
preliminary · human dataExploratory meta-analysis of just 11 randomised or crossover trials totalling 303 mostly young participants of varied training status, with interventions running from 4 weeks to 12 months; the confidence interval spans zero in both directions, so it shows no clear difference rather than proven equivalence.
An umbrella review of 78 meta-analyses covering 177 373 participants found app-based interventions improved blood pressure, HbA1c, fasting and post-meal glucose, bodyweight, waist circumference, physical activity, diet quality, mood and medication adherence versus controls. There was no significant effect on cardiovascular mortality, cholesterol or triglycerides, body fat, hospitalisation or smoking abstinence.
preliminary · human dataAn umbrella review of existing reviews, so quality is inherited: only 1% of the 78 included reviews was rated high quality and 73% critically low, heterogeneity was very high for most outcomes, and several authors are employed by a food company.
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This page collects what our published, cited studies say; it is information, not medical advice. Have a different question? Ask it here.