High-fat Diet Coupled with Aerobic Exercise Has a Sexually Dimorphic Effect on the Biochemical Profile and Anxiety-like Behaviour of Adolescent Wistar Rats.

Background: Childhood exposure to a high-fat diet (HFD) has long-term implications on metabolism and behaviour. Exercise and switching to a normal low-fat diet during adulthood can sometimes reverse a few biochemical consequences of HFD exposure during childhood.

Purpose: This study proposes to address the effect of aerobic exercise on HFD-induced metabolic and behavioural changes by observing the biometric, biochemical and anxiety-like behaviour assessed by elevated plus maze in adolescent male and female Wistar rats.

Methods: Fourteen female and 18 male wistar rat pups aged 35 days were divided into 3 groups [control, HFD+exercise and HFD]. The HFD and HFD+exercise alone received HFD for 10 weeks. In addition HFD +exercise were subjected to forced swimming for 30 minutes 5 days a week for 4 last weeks. At the end of 10th week, elevated plus maze recording was done to assess anxiety.

Results: We observed that both male and female Wistar rats' body weight increased within 2 weeks of HFD exposure and continued to increase till 5th week. In male rats, after 4 weeks of exercise, the weight was comparable to that of the control group, while weight decreased in female rats. In both males and females, plasma glucose and lipid profiles were increased after HFD. However, exercise seems to lower these in the HFD + exercise group. Female HFD + exercise group rats showed a significantly higher number of exits from closed arm to open arm and climbing than their sex-matched control on Day 3.

Conclusion: This shows that the exercise ameliorated the anxiogenic behaviour in HFD-fed adolescent female rats but not in male rats to the same extent. When combined, these findings highlight that HFD and exercise throughout adolescence have sex-specific differential effects on biometric, biochemical, and anxiety-like behaviour.