ABSTRACT
OBJECTIVE: The impact of early-life stress on weight-loss maintenance is unknown. METHODS: Mice underwent neonatal maternal separation (NMS) from 0 to 3 weeks and were weaned onto a high-fat sucrose diet (HFSD) from 3 to 20 weeks. Calorie-restricted weight loss on a low-fat sucrose diet (LFSD) occurred over 2 weeks to induce a 20% loss in body weight, which was maintained for 6 weeks. After weight loss, half of the mice received running wheels, and the other half remained sedentary. Mice were then fed ad libitum on an HFSD or LFSD for 10 weeks and were allowed to regain body weight. RESULTS: NMS mice had greater weight regain, total body weight, and adiposity compared with naïve mice. During the first week of refeeding, NMS mice had increased food intake and were in a greater positive energy balance than naïve mice. Female mice were more susceptible to NMS-induced effects, including increases in adiposity. NMS and naïve females were more susceptible to HFSD-induced weight regain. Exercise was beneficial in the first week of regain in male mice, but, long-term, only those on the LFSD benefited from exercise. As expected, HFSD led to greater weight regain than LFSD. CONCLUSIONS: Early-life stress increases weight regain in mice.
Subject(s)
Adverse Childhood Experiences , Mice , Male , Female , Animals , Maternal Deprivation , Obesity/etiology , Weight Loss , Weight Gain , SucroseABSTRACT
Early life stress increases obesity risk, but its impact on weight loss maintenance is unknown. Mice underwent neonatal maternal separation (NMS) from 0-3 weeks and were weaned onto high fat sucrose diet (HFSD) from 3-20 weeks. Calorie-restricted weight loss on a low fat sucrose diet (LFSD) occurred over 2 weeks to induce a 20% loss in body weight, which was maintained for 6 weeks. After weight loss, half the mice received running wheels (EX) the other half remained sedentary (SED). Mice were then fed ad libitum on HFSD or LFSD for 10 weeks and allowed to regain body weight. NMS mice had greater weight regain, total body weight and adiposity compared to naïve mice. During the first week of refeeding, NMS mice had increased food intake and were in a greater positive energy balance than naïve mice, but total energy expenditure was not affected by NMS. Female mice were more susceptible to NMS-induced effects, including increases in adiposity. NMS and naïve females were more susceptible to HFSD-induce weight regain. Exercise was beneficial in the first week of regain in male mice, but long-term only those on LFSD benefited from EX. As expected, HFSD led to greater weight regain than LFSD.
