Effect of intermittent energy restriction on weight loss compared to continuous energy restriction in overweight and obese adults: A systematic review

Introduction: Intermittent energy restriction (REI) and continuous energy restriction (REC) are effective strategies for reducing body weight in adults. In REI, intake is limited for less than 24 hours with periods of total or partial energy restriction (75-90%). They are generally applied during six to eight hours between one and seven days a week, followed by a regular feeding period. In REC, intake is reduced by 15-60% of the daily energy requirement. The aim of the present review was to verify the possible greater effect of REI on weight loss compared to REC in overweight and obese adult men and women. Material and Methods: A systematic review was performed, including clinical, original studies; conducted in overweight or obese men and women, who focused on weight loss using REI compared to REC over the past eight years (2011-2019). The databases used for the electronic search were PubMed, Cochrane Library and Web of Science. 531 articles were obtained, of which only ten met the inclusion criteria for the present systematic review. Results: REI and REC methods used individually, as well as in combination with each other, facilitate body weight loss in a similar way in overweight and obese adult men and women, even in people with type 1 diabetes mellitus. Conclusions: Weight loss was mainly mediated by energy restriction, REI was not superior to REC as a therapeutic intervention, since weight loss seems to be mediated by the level of energy restriction and not because it is performed continuously or discontinuous.