Intermittent fasting can be unsafe for teenagers: Study raises important questions about who should and shouldn’t try it

The research challenges the one-size-fits-all approach to intermittent fasting, indicating that age should be a key factor when considering this eating pattern.

A new study highlights the need for teens to consult with a healthcare professional before starting any intermittent fasting regimen to discuss the potential risks and benefits, and determine the best approach for their individual needs. The study published in Cell Reports found that short-term fasting was safe for all age groups, but long-term fasting caused problems with insulin production in young people that resembled early-stage Type 1 diabetes.

A new study found that while intermittent fasting improved health markers in older mice, it actually impaired important cellular development in younger ones. (Representative picture: Shutterstock)

Potential risks of intermittent fasting for teens

The German study found that intermittent fasting had opposing effects on mice of different ages. While it improved health in older mice, it harmed pancreatic cell development in young mice, suggesting potential risks for adolescents and young adults.

The study's findings indicate that age plays a crucial role in determining the benefits or risks of intermittent fasting. Prolonged fasting was shown to impair cell development in younger individuals, particularly affecting insulin-producing beta cells. These results raise concerns about the safety of intermittent fasting for children and teenagers.

“Our study confirms that intermittent fasting is beneficial for adults, but it might come with risks for children and teenagers,” says Stephan Herzig, a professor at Technical University of Munich and director of the Institute for Diabetes and Cancer at Helmholtz Munich, in a statement.

More about the study

The study looked at three groups of mice: young (equivalent to adolescence in humans), middle-aged (adult), and elderly. Each group followed an eating pattern where they fasted for 24 hours, followed by 48 hours of normal eating. The researchers tracked how this affected their bodies over both short periods (5 weeks) and longer periods (10 weeks).

At first, all age groups showed improvements in how their bodies handled sugar, which, of course, is a positive sign. But after extended periods of intermittent fasting, significant differences emerged between age groups. While older and middle-aged mice continued to show benefits, the young mice began showing troubling changes.

“Intermittent fasting is usually thought to benefit beta cells, so we were surprised to find that young mice produced less insulin after the extended fasting,” explains co-lead author Leonardo Matta, from Helmholtz Munich.

The older mice, however, actually benefited from the extended fasting periods. Their insulin-producing cells worked better, and they showed improved blood sugar control. Meanwhile, middle-aged mice maintained stable function, suggesting that mature bodies handle fasting periods differently than developing ones.

This age-dependent response challenges the common belief that intermittent fasting is suitable for everyone. The research suggests that while mature adults might benefit from this eating pattern, young people could be putting themselves at risk, particularly if they maintain the practice for extended periods.

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.