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Updated: Apr 11, 2026
Assessment of the Metabolic Effects of Isocaloric 2:1 Intermittent Fasting in Mice
Published on: November 27, 2019
Dietary Protein to Carbohydrate Ratio and Caloric Restriction: Comparing Metabolic Outcomes in Mice
Samantha M Solon-Biet1, Sarah J Mitchell2, Sean C P Coogan3
1Charles Perkins Centre, University of Sydney, Sydney, NSW 2006, Australia; Ageing and Alzheimers Institute and ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, NSW 2139, Australia; School of Biological Sciences, University of Sydney, Sydney, NSW 2006, Australia.
Abstract:
Both caloric restriction (CR) and low-protein, high-carbohydrate (LPHC) ad-libitum-fed diets increase lifespan and improve metabolic parameters such as insulin, glucose, and blood lipids. Severe CR, however, is unsustainable for most people; therefore, it is important to determine whether manipulating macronutrient ratios in ad-libitum-fed conditions can generate similar health outcomes. We present the results of a short-term (8 week) dietary manipulation on metabolic outcomes in mice. We compared three diets varying in protein to carbohydrate ratio under both CR and ad libitum conditions. Ad libitum LPHC diets delivered similar benefits to CR in terms of levels of insulin, glucose, lipids, and HOMA, despite increased energy intake. CR on LPHC diets did not provide additional benefits relative to ad libitum LPHC. We show that LPHC diets under ad-libitum-fed conditions generate the metabolic benefits of CR without a 40% reduction in total caloric intake.
