PMID- 38004232 OWN - NLM STAT- MEDLINE DCOM- 20231127 LR - 20231127 IS - 2072-6643 (Electronic) IS - 2072-6643 (Linking) VI - 15 IP - 22 DP - 2023 Nov 19 TI - Effects of Diet Macronutrient Composition on Weight Loss during Caloric Restriction and Subsequent Weight Regain during Refeeding in Aging Mice. LID - 10.3390/nu15224836 [doi] LID - 4836 AB - Caloric restriction (CR) induces weight loss, but is associated with rapid weight regain upon return to ad libitum feeding. Our aim was to investigate effects of the macronutrient composition of the diet on weight loss and regain in elderly mice. Males, 18 months old, of the C57BL/6J strain were subjected to 4-week 30% CR followed by 4 weeks of ad libitum refeeding on either high-carb (HC), high-fat (HF) or high-protein (HP) diets (n = 22 each). Mice (n = 11) fed a chow diet ad libitum served as a control group (CON). Body mass and food intake were monitored daily. Twenty-four-hour indirect calorimetry was used to assess energy expenditure and substrate oxidation. Muscle and fat mass were evaluated with dissection of the tissues. Serum leptin and ghrelin levels were also measured. CR-induced weight loss did not differ between the diets. Weight regain was particularly fast for HF as mice overshot their initial weight by 12.8 +/- 5.7% after 4-week refeeding when HC and HP mice reached the weight of the CON group. Weight regain strongly correlated with energy intake across the groups. The respiratory exchange ratio was lower in HF mice (0.81 +/- 0.03) compared to HC (0.94 +/- 0.06, p < 0.001), HP (0.89 +/- 0.04, p < 0.001) and CON mice (0.91 +/- 0.06, p < 0.01) during the refeeding. Serum leptin levels were higher in HF mice (1.03 +/- 0.50 ng/mL) compared to HC (0.46 +/- 0.14, p < 0.001), HP (0.63 +/- 0.28, p < 0.05) or CON mice (0.41 +/- 0.14, p < 0.001). Thus, CR induces similar weight loss in aging mice irrespective of the diet's macronutrient composition. An HF diet leads to excessive energy intake and pronounced gain in body fat in spite of increased fat oxidation and serum leptin during the refeeding after CR. FAU - Minderis, Petras AU - Minderis P AUID- ORCID: 0000-0001-9522-6050 AD - Institute of Sport Science and Innovations, Lithuanian Sports University, 44221 Kaunas, Lithuania. FAU - Fokin, Andrej AU - Fokin A AD - Institute of Sport Science and Innovations, Lithuanian Sports University, 44221 Kaunas, Lithuania. FAU - Povilonis, Tomas AU - Povilonis T AD - Faculty of Medicine, Lithuanian University of Health Sciences, 44307 Kaunas, Lithuania. FAU - Kvedaras, Mindaugas AU - Kvedaras M AD - Institute of Sport Science and Innovations, Lithuanian Sports University, 44221 Kaunas, Lithuania. FAU - Ratkevicius, Aivaras AU - Ratkevicius A AUID- ORCID: 0000-0002-4737-5817 AD - Department of Health Promotion and Rehabilitation, Lithuanian Sports University, 44221 Kaunas, Lithuania. AD - Sports and Exercise Medicine Centre, Queen Mary University of London, London E1 4NS, UK. LA - eng PT - Journal Article DEP - 20231119 PL - Switzerland TA - Nutrients JT - Nutrients JID - 101521595 RN - 0 (Leptin) SB - IM MH - Humans MH - Male MH - Mice MH - Animals MH - Infant MH - *Leptin MH - *Caloric Restriction MH - Mice, Inbred C57BL MH - Weight Loss MH - Energy Intake MH - Nutrients MH - Diet, High-Fat MH - Weight Gain MH - Body Weight PMC - PMC10675209 OTO - NOTNLM OT - diets OT - fat loss OT - weight cycling COIS- The authors declare no conflict of interest. EDAT- 2023/11/25 12:45 MHDA- 2023/11/27 12:44 PMCR- 2023/11/19 CRDT- 2023/11/25 01:21 PHST- 2023/10/18 00:00 [received] PHST- 2023/11/07 00:00 [revised] PHST- 2023/11/16 00:00 [accepted] PHST- 2023/11/27 12:44 [medline] PHST- 2023/11/25 12:45 [pubmed] PHST- 2023/11/25 01:21 [entrez] PHST- 2023/11/19 00:00 [pmc-release] AID - nu15224836 [pii] AID - nutrients-15-04836 [pii] AID - 10.3390/nu15224836 [doi] PST - epublish SO - Nutrients. 2023 Nov 19;15(22):4836. doi: 10.3390/nu15224836.