For some time now, intermittent fasting has been gaining followers and has become the fashionable alternative to achieve lose weight. In addition, several investigations relate the periodic food restriction with the reduction of the risk of pathologies associated with age, including cardiovascular disease, diabetes, cancer and dementia. However, a new study carried out in animals has brought to light a potential drawback. According to new research from the University of East Anglia (UK)time-restricted fasting diets could cause fertility problems.
The study, published in the journal ‘Proceedings of the Royal Society B’ shows that time-restricted feeding in female zebrafish impairs the quality of the eggs. Likewise, males also showed a reduced sperm velocity. Also, some of these Negative effects they were observed after the fish recovered their normal levels of food consumption. The researchers say that although the study was conducted in fish, their findings highlight the importance of considering not only the effect of fasting on weight and health, but also fertility.
Alexei Maklakov, co-author of the UEA work, explains that “time-restricted fasting is an eating pattern that limits food consumption to certain hours of the day. It is a very popular trend in the field of health and physical fitness, and people do it to lose weight and improve their health, but the way in which bodies respond to food shortages can affect the quality of eggs and sperm, and these effects could continue after the fasting period ends “. “We wanted to find out more about how these kinds of diets might affect fertility in a popular model organism,” he adds.
To do this, the scientists measured how males and females allocate resources to body maintenance versus sperm and egg production and maintenance, and the quality of the resulting offspring. Edward Ivimey-Cook, from the UEA’s Faculty of Biological Sciences explains that they found “that time-restricted fasting affects reproduction differently in males and females. Once the fish returned to their normal feeding schedule, females increased the number of offspring they produced at the expense of egg quality, which resulted in a reduction in the quality of offspring.to. The sperm quality of the males also decreased.”
The research team stresses the importance of taking into account not only the effect of fasting on the maintenance of the organism, but also on the production of eggs and sperm. However, he concludes that “more research is needed to understand how long it takes for sperm and egg quality to return to normal after the fasting period.”