An international study found that intermittent fasting has little or no benefit for adults who are overweight or obese, but Australian researchers raised questions about the limitations of this review.
A report from a Cochrane review found that the results of intermittent fasting are so poor compared to other weight loss methods that obese adults are better off following traditional diet advice or doing nothing at all.
The international researchers analyzed evidence from 22 randomized clinical trials involving around 2000 adults, including participants from Australia, and looked at data on different intermittent fasting methods, including alternate-day fasting, periodic fasting and time-restricted feeding.
They found that intermittent fasting did not appear to have a clinically meaningful effect on weight loss.
Professor Leonie Heilbron, Group Leader in Obesity and Metabolism at the University of Adelaide, said the results of the Cochrane review were similar to dozens of similar meta-analyses on the subject, with intermittent fasting producing weight loss similar to other moderate calorie restriction interventions of around 7% after six to 12 months, and much better than other weight loss methods such as very low calorie diets (10 to 15%) and pharmacotherapy. (15-20%) or surgery (>20%).
However, she says a limitation of this latest study is that different types of intermittent fasting should not have been combined into one review, and it did not take into account the broader health benefits beyond weight loss.
“This review combines different forms of intermittent fasting, which is incorrect,” Professor Heilbron says.
“There are different types of ‘intermittent fasting’, but these do not apply to weight loss and should not be used together.”
“There is some evidence that time-restricted eating improves health despite modest weight loss because it better aligns circadian rhythms.”
Professor Heilbron said the review included very little research to reach its conclusions.
“The type of control is important. Some people in the control group were not completely inactive or on a waiting list. They were receiving information and guidance to lose weight. This reduces the apparent difference between intermittent fasting and control,” she says.
“These are lumping together meals that shouldn’t be together, giving uneven results. This results in heterogeneity…including diabetic patients who are generally resistant to weight loss (even with semaglutide). ”
Professor Heilbron says that based on the available scientific evidence, GPs can confidently recommend intermittent fasting as a proven alternative to continuous calorie restriction over a period of 6 to 12 months.
“Many people find it very difficult to keep losing weight beyond 12 months, no matter what approach you take,” she says.
“This is because your body has biological mechanisms that help you regain weight after weight loss.”
“For example, levels of satiety peptides and other hormones that make you feel full are reduced, leptin is also reduced, reducing energy expenditure, and hunger hormones such as ghrelin are increased.”
“As a result, people often regain weight after a year, whether they follow a calorie-restricted diet or use intermittent fasting.”
“Exercise and weight loss drugs can help maintain weight loss by countering these biological signals.”
Nance Haxton was a journalist at ABC for nearly 20 years. She has also worked as an advocate on the Disability Royal Commission, helping people with disabilities tell their stories, and as a senior reporter for the National Indigenous Radio Station.
During that time, she has won various accolades in Australia and abroad, including two Walkley Awards and three New York Festival Radio Awards trophies.
Currently freelancing as The Wandering Journo, Nance self-produces a podcast that includes personal audio slices of Australia’s ‘Streets of Your Town’.
Subscribe for free Insight+ weekly newsletter here. It can be viewed by all readers, not just registered physicians.
#Intermittent #fasting #beneficial #research #results #InSight