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Abstract Disclosure: I.F. Miranda: None. L.M. Carvalho: None. M.B. Neves: None. C.M. Breves: None. I.S. Andrade: None. V.M. Nascimento: None. T.M. Cristina: None. A.F. Ferreira: None. V.S. Pinto: None. R.S. Fortunato: None. Background: Intermittent fasting (IF) is a dietary strategy that is effective in improving body composition and metabolic parameters, which seems to be associated with improvements in adipose tissue physiology. However, recent studies suggest that, in the long term, fasting may contribute to adiposity gain and insulin resistance. Furthermore, the onset of these putative effects, and whether males and females are impacted in the same way, has not yet been explored. Therefore, it is important to assess, from a temporal and sexual perspective, how such intervention impacts these parameters. Methods: Forty 3-month-old Wistar rats were divided into four groups: male control (MC = 10), male IF (MIF = 10), female control (FC = 10), and female IF (FIF = 10). IF involved every-other-day fasting over 12 weeks. Food intake and body weight were measured daily and weekly, respectively. Glucose tolerance test, feeding behavior, and fasting blood glucose were evaluated after 4, 8, and 12 weeks of intervention. The retroperitoneal, gonadal, inguinal, and interscapular brown adipose tissues were extracted and weighted. The reduced thiol content, oxidative damage, and the activity of antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase were analyzed in the retroperitoneal adipose tissue. Student's t-test and two-way ANOVA were used for statistical analysis, performed in GraphPad Prism 8.0.1, with p0.05 considered statistically significant. Results: Body weight gain was lower after IF only in males (p 0.0001). IF induced a 30% and 23% caloric deficit in males and females, respectively. However, the IF groups presented an overfeeding behavior after 4, 8 and 12 weeks males (p 0.05); females (p 0.05). The weight of retroperitoneal males (p 0.001); females (p 0.05) and gonadal males (p 0.05); females (p 0.01) fad pads were lower in the IF groups of both sexes, while IF reduced the inguinal fat depot weight only in males (p 0.0001). Nevertheless, the weight of brown adipose tissue was higher after IF in females in comparison to their control (p 0.05). IF groups had lower area under the curve (AUC) in the glucose tolerance test after 4 males (p 0.05); females (p 0.05) and 8 weeks [males (p 0.05); females (p 0.0001)) compared to their respective controls. Although only IF females maintained lower AUC compared to the control group after 12 weeks of intervention (p 0.0001). In the retroperitoneal tissue, only FIF group presented higher catalase activity (p 0.05), reduced thiol content (p 0.01), and lower carbonylated protein levels when compared to FC (p 0.05). Conclusion: These results indicate that IF improves the response to the glucose tolerance test in both males and females in the short term. Nonetheless, only females maintain this effect in the long term, which could be attributed to better redox homeostasis in retroperitoneal adipose tissue. Presentation: 6/1/2024
Miranda et al. (Tue,) studied this question.