University of Toronto: Study finds intermittent fasting may not be as safe as we thought

A recent study published in the journal Eating Behavior sheds light on the potential negative effects of intermittent fasting, a popular dietary trend in which people fast for more than eight hours at a time. Although intermittent fasting is often promoted as a way to improve health and control or lose weight, little research has been conducted on its potential risks.

According to the study, which analyzed data from more than 2,700 adolescents and young adults in Canada, intermittent fasting was associated with disordered eating behaviors in women, including binge eating and compensatory behaviors such as vomiting and compulsive exercise. Men who practiced intermittent fasting were also more likely to report compulsive exercise.

The prevalence of intermittent fasting behaviors among adolescents and young adults was noteworthy. In total, 47% of females, 38% of males, and 52% of transgender or gender non-conforming individuals reported engaging in intermittent fasting in the past 12 months.

"Given our findings, it's a question of how common intermittent fasting is in our sample," said lead author Kyle T. Ganson, PhD, assistant professor at the Factor-Inwentash School of Social Work at the University of Toronto.

Across all three groups, participants reported that they had tried intermittent fasting an average of 100 days in the past 12 months.

“The associations found between intermittent fasting and disordered eating behaviors are particularly salient given the significant increase in disordered eating among adolescents and young adults since the start of the COVID-19 pandemic,” said Jason M. Nagata, MD, MSc, assistant professor at UCSF. “These findings raise a red flag for health care professionals recommending intermittent fasting as a means of weight loss because it may promote disordered eating attitudes and behaviors.”

“We need more education in healthcare settings and increased awareness in popular culture, including on social media, about the potential harms of intermittent fasting,” Ganson said. “At this point, the proposed benefits remain unclear and unsupported by research, while the potential harms are becoming increasingly clear.”

From cnBeta