Does a moderate carbohydrate restriction result in fewer symptoms of dietary induction and greater maintenance of mood, with comparable cardiometabolic results, when compared to more extreme carbohydrate restriction in healthy volunteers?

Key findings: • Reduced carbohydrate diets have a positive effect on markers of health • Low-carbohydrate diets were easily adhered to over a 12-week period • There were significant and clinically meaningful improvements in weight, waist-height ratio, HDL-c and TG. • All diets were functionally ketogenic based on the mean level of BOHB achieved per group • A 5% carbohydrate allocation is consistently ketogenic for almost all participants, but a low-carbohydrate intervention of 25% or 15% carbohydrate can be ketogenic for some people. • Symptoms of carbohydrate withdrawal increased concomitant to the magnitude of carbohydrate restriction, but the changes from baseline were small, and there was no significant difference between intervention groups. • Mean reported symptoms differed by less than 2 out of a possible score of 48 (range between groups; 3.00 - 4.95), and there is little clinically meaningful difference in adverse effects of carbohydrate withdrawal between diets differing in carbohydrate restriction. • The ‘keto-flu’ is limited to the symptoms of breath expression of ketone bodies and a minor increase in muscle weakness. • Mood improved significantly from baseline as a result of all dietary interventions but did not differ significantly between groups