Intermittent fasting is beneficial for body weight regulation and reproductive phenotypes in high-fat diet-fed male mice

Excessive body weight can impair health and leads to a range of noncommunicable diseases. Intermittent fasting (IF), an eating pattern that cycles between periods of eating and fasting, is an increasingly popular method of weight loss. To minimize negative impacts of both overconsumption and underconsumption caused by prolonged fasting, IF without reducing caloric intake has been implemented. The present study investigated the effect of IF, i.e., alternate-day fasting (ADF) and time-restricted feeding (TRF), without reducing caloric intake on reproductive functions in male C57BL/6 mice. Sexually mature mice were divided into four groups and fed for seven weeks a standard diet (control) or a diet enriched in fat without (HFD) or with IF (HFD˗ADF and HFD˗TRF). Upon sacrifice, body and reproductive organ (the testes, epididymides, and vas deferens) weights were measured in grams. Epididymal sperm characteristics such as concentration, motility, and morphology and plasma testosterone levels were determined. Compared with a standard diet, the unlimited consumption of a high-fat diet caused a significant increase in body weight of mice (p = 0.001). Ratio of final to initial weights in these animals (1.55 ± 0.06) were also significantly higher than 1.19 ± 0.04 in HFD˗ADF and 1.17 ± 0.03 in HFD˗TRF males (p = 0.006 to p = 0.027), which both values did not differ from 1.21 ± 0.21 in control animals. Reproductive organ weight relative to body weight (%) was significantly lower in high-fat diet-fed male mice than controls (p = 0.014 to p = 0.03), possibly as a result of higher body weights. No significant difference was, however, observed in the levels of testosterone and in vitro sperm characteristics among groups. In conclusion, despite no a noticeable impact on the male reproductive system, overconsumption of a high-fat diet caused a substantial increase in body weight, and this undesired effect could be mitigated with doing IF.