PhD defence: Protein Restriction and Metabolic Regulation in Humans

Aslak Emil Lyster

PhD thesis

The global obesity epidemic represents a major health concern. In rodent models, dietary protein restriction without energy restriction elevates energy expenditure, reduces body weight and improves metabolic health, effects largely mediated by the liver-derived hormone FGF21. However, whether these effects translate to humans remains unclear.

This PhD project investigated the metabolic effects of protein restriction, meeting minimum protein requirements, in men, focusing on body weight regulation, energy and glucose homeostasis, and the potential role of FGF21.

The findings demonstrate that protein restriction influences energy balance in lean men and can promote weight loss in men with obesity without energy restriction. The metabolic effects of protein restriction appear to be mediated, at least in part, by FGF21, potentially through adaptations in adipose tissue metabolism. These results suggest that protein restriction, independent of energy restriction, may represent a viable dietary strategy for weight loss.

2025, 148 pages.

TIme

11 November 2025, 14:00

Place

August Krogh Building, Auditorium 1, Universitetsparken 13, DK-2100 Copenhagen.

Assessment Committee

Professor Thomas Elbenhardt Jensen (chair), Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark.

Niels Jessen, Head of Research and Professor of Clinical Pharmacology at Steno Diabetes Center Aarhus, Aarhus University Hospital, Denmark.

Birgitte Stampe Andersen, Scientific Vice President, Diabetes, Obesity and MASH, Global Drug Discovery, Novo Nordisk A/S, Måløv, Denmark.

Supervisor

Professor Bente Kiens, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark.

Copy of thesis

Ask for a copy of the thesis here: bkiens@nexs.ku.dk