Recent study highlights developmental risks associated with extended fasting in young people, urging caution over universal fasting advice for teenagers and children.
Intermittent fasting may help some adults manage weight and blood sugar, but new research suggests the approach can carry different risks during adolescence. A study published in Cell Reports by researchers at the Technical University of Munich, LMU Hospital Munich and Helmholtz Munich found that fasting cycles improved glucose control in adult and older mice, yet long-term fasting impaired pancreatic beta-cell development in younger animals. Beta cells produce insulin, the hormone that helps regulate blood sugar. In the adolescent mice, prolonged fasting reduced insulin output and disrupted the cells’ normal maturation.
The findings matter because the adolescent pancreas is still developing. In the study, long-term fasting altered key growth and function pathways, including mTORC1 signalling, and lowered levels of proteins linked to insulin production and glucose handling. The researchers said the changes in younger mice resembled patterns seen in type 1 diabetes, which suggests that extended fasting during growth could interfere with the body’s ability to build a healthy insulin-producing system.
That concern is not just theoretical. A scoping review indexed by PubMed, looking at intermittent fasting regimens in people aged 10 to 25, found early promise for obesity treatment but also noted that the evidence base remains limited and inconsistent. The review said more rigorous trials are needed before fasting can be judged a reliable strategy for young people. Separate studies in adolescents and young adults have also shown that fasting can shift metabolic markers in the short term, but those changes do not necessarily prove lasting benefit.
The broader message is that intermittent fasting is not a universal prescription. The Munich researchers said adults may benefit, but children and teenagers could face developmental risks if fasting is prolonged or too restrictive. For families worried about weight gain or blood sugar, the evidence points towards a more cautious approach in younger people, with an emphasis on balanced nutrition, regular meals and age-appropriate medical advice rather than one-size-fits-all fasting plans.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
