Research results have shown that intermittent fasting negatively affects blood sugar control in adolescents.
Researchers from the Technical University of Munich (TUM) announced that their study, conducted in collaboration with researchers from LMU Hospital and the Helmholtz Munich Institute, found that while intermittent fasting has a positive effect on adults, it could have negative effects on adolescents in their growth phase. The research results were published in the international journal Cell Reports on Jan. 25.
Intermittent fasting is a dietary regimen that adjusts only the timing of food intake without changing the quantity or types of food consumed. Typically, it includes methods such as the '16:8' method, which involves fasting for 16 hours and eating within an 8-hour window, and the '5:2' method, which allows normal eating for 5 days and restricts intake for 2 days. Intermittent fasting is generally known to be effective for weight loss and the prevention of heart disease.
The researchers divided mice into adolescent, adult, and elderly groups to compare the effects of intermittent fasting. They conducted experiments for 10 weeks, during which the mice normally consumed food for two days and fasted for one day. The results showed improved insulin sensitivity in adult and elderly mice. This means that their metabolism responded better to insulin produced by the pancreas, leading to enhanced blood sugar control, which could positively impact diabetes prevention.
However, adolescent mice exhibited a decrease in the function of beta cells, which produce insulin in the pancreas. Leonardo Mata, a researcher from the Helmholtz Munich Institute participating in the study, noted, "While it is generally known that intermittent fasting has a positive effect on beta cells, we obtained unexpected results showing a decrease in insulin production in adolescent mice."
Using single-cell sequencing techniques to analyze changes in beta cells, the researchers found that beta cells in adolescent mice were abnormally undeveloped. In contrast, adult mice had already matured beta cells. The undeveloped beta cells in adolescent mice did not show the positive effects of intermittent fasting due to inhibited growth, leading to negative outcomes.
The immature beta cell phenomenon observed in adolescent mice was also seen in tissue data from actual diabetes patients. Professor Stephan Herzig from TUM and the Helmholtz Munich Institute, who led the study, said, "This research suggests that while intermittent fasting is beneficial for adults, it could pose risks to adolescents in their growth phase," and added, "If we can elucidate the mechanisms that promote beta cell development in the future, new possibilities for diabetes treatment will arise."
References
Cell Reports (2025), DOI : https://doi.org/10.1016/j.celrep.2024.115225