Research paper
Harvie M, Howell A. Potential benefits and harms of intermittent energy restriction and intermittent fasting amongst obese, overweight and normal weight subjects — a narrative review of human and animal evidence. Behavioral Sciences. 2017;7(1):4. doi:10.3390/bs7010004. PMID: 28106818. PMCID: PMC5371748.
Why we cite it
Narrative review in *Behavioral Sciences* evaluating six randomized IER-CER comparisons for weight management across different weight categories. Covers both potential benefits and potential harms, including sex differences in metabolic responses and effects on normal-weight individuals. Key finding: in six *"small short term (<6 month)"* trials, IER equals CER for weight loss, with one showing superior body fat reduction and two showing greater insulin resistance improvements — importantly, the insulin sensitivity gains were independent of body fat changes. Introduces the "carry over effect" where IER dieters spontaneously reduce intake on non-restricted days. Also covers metabolic flexibility, FFM preservation, safety, and menstrual cycle effects. Its conclusion: *"The longer term benefits or harms of IER amongst people who are overweight or obese, and particularly amongst normal weight subjects, is not known"* (scope and conclusion added 2026-09-19; *Distinctively* removed). Referenced in companion 421 as a balanced review of fasting adaptation and outcomes.