Intermittent fasting – one of the most popular celebrity dieting techniques – could trigger type 2 diabetes, research suggested today.
Hollywood A-listers like Jennifer Aniston, Nicole Kidman, Cameron Diaz and Mark Wahlberg have jumped on the trend since it shot to prominence in the early 2010s.
But, despite swathes of studies suggesting it works, experts have remained divided over its effectiveness and the potential long term health impacts.
Now a study on mice has claimed that while fasting may be good for your waistline, among teenagers it could thwart insulin production.
Type 2 diabetes occurs when the body doesn’t make enough insulin or the insulin it makes doesn’t work properly.
German researchers said this was because beta cells — specialized cells in the pancreas that produce insulin — in the younger mice failed to mature properly.
Critically, the scientists found this phenomenon was only seen in adolescent mice — not adult or older mice, suggesting time-restricted fasting affects age groups differently.
Dr Alexander Bartelt, a professor of cardiovascular metabolism at the Technical University of Munich and study co-author, said: ‘Intermittent fasting is known to have benefits, including boosting metabolism and helping with weight loss and heart disease.
Jennifer Aniston , Chris Pratt and Kourtney Kardashian are among the Hollywood A-listers to have jumped on the trend since it shot to prominence in the early 2010s. But, despite swathes of studies suggesting it works, experts have remained divided over its effectiveness and the potential long term health impacts
A study on mice suggests that while fasting may be good for your waistline, among teenagers it could thwart insulin production
‘But until now, its potential side effects weren’t well understood.’
Dr Stephan Herzig, director of the Institute for Diabetes and Cancer at Helmholtz Centre Munich and study co-author, added: ‘Our study confirms that intermittent fasting is beneficial for adults, but it might come with risks for children and teenagers.’
‘The next step is digging deeper into the molecular mechanisms underlying these observations.
‘If we better understand how to promote healthy beta cell development, it will open new avenues for treating diabetes by restoring insulin production.’
In the study, researchers assessed the food intake of three groups of mice, 2-month old considered adolescent, 8-month old or middle aged and 18-month-old, dubbed ‘old’.
They followed a cycle of going 24 hours without food, before being fed normally for two days.
After a follow-up of 10 weeks, the researchers found that insulin sensitivity improved in both the adult and older mice, meaning their metabolism responded better to insulin produced by the pancreas.
Writing in the journal Cell Reports, however, they said adolescent mice showed a ‘troubling decline in their beta cell function’.
Almost 4.3 million people were living with diabetes in 2021/22, according to the latest figures for the UK. And another 850,000 people have diabetes and are completely unaware of it, which is worrying because untreated type 2 diabetes can lead to complications including heart disease and strokes
Tests to uncover why this occurred later found this was because the beta cells in the younger mice failed to mature properly.
They then compared their findings on mice to data from human tissues.
The scientists said that in patients with diabetes, their beta cells showed ‘similar signs’ of a failure to mature properly.
Dr Leonardo Matta, a researcher in molecular biology at the Helmholtz Centre, said: ‘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.’
Type 2 diabetes occurs when the body doesn’t make enough insulin or the insulin it makes doesn’t work properly.
This hormone is needed to bring down blood sugar levels.
Having high blood sugar levels over time can cause heart attacks and strokes, as well as problems with the eyes, kidneys and feet.
Sufferers may need to overhaul their diet, take daily medication and have regular check-ups.
Symptoms of the condition, which is diagnosed with a blood test, include excessive thirst, tiredness and needing to urinate more often. But many people have no signs.
Almost 4.3million people were living with diabetes in 2021/22, according to the latest figures for the UK.
Approximately 90 per cent of diabetes cases are type 2 diabetes, which is linked with obesity and is typically diagnosed in middle age, rather than type 1 diabetes, a genetic condition usually identified early in life.
