Obesity May Disrupt Metabolic Benefits of Intermittent Fasting, Experts Warn

Recent research has revealed that intermittent fasting, a popular weight loss method, may not work as effectively for people who are obese. A study published last month found that while fasting triggered beneficial metabolic changes in healthy mice, the same did not occur in obese mice.

The researchers at the University of Tokyo discovered that when healthy mice were deprived of food, their livers quickly adapted by shifting from storing energy to burning fat, helping the mice lose weight. However, this metabolic "switch" did not happen in the obese mice, suggesting obesity may introduce a kind of "metabolic jet lag" that disrupts the body's ability to reap the full benefits of fasting.

The findings raise questions about the one-size-fits-all approach to intermittent fasting, which has grown increasingly popular in recent years. Experts are now investigating whether there are specific markers in the blood that could help identify who is likely to benefit from fasting and who may struggle.

Meanwhile, the debate continues around exactly how intermittent fasting leads to weight loss. Some experts believe it is simply a matter of reduced calorie intake, while others argue that fasting directly activates other metabolic mechanisms. A recent review of 99 studies found alternate-day fasting to be the most effective form for weight loss, but the author notes that for many, a 3.6kg loss may not make a significant difference to their health.

Ultimately, the research suggests that while intermittent fasting can be an effective tool, it may not work for everyone - especially those who are obese. Personalized approaches and a combination of dietary changes may be needed to achieve sustainable weight loss for those struggling with obesity.