Healthcare (Commonwealth Union) – Intermittent fasting is equally successful for weight loss as conventional calorie-cutting diets, according to a recent evidence review conducted by experts at the University of Toronto.
When compared to diets that impose no restrictions, the results, which were published in the BMJ, show that intermittent fasting, a dietary trend that has gained popularity over the past ten years, also improves cardiometabolic health markers like blood pressure and cholesterol levels.
Alternate-day fasting, which calls for people to fast for 24 hours every other day, produced the most noticeable short-term effects among the different fasting strategies. Nonetheless, the researchers stressed that additional long-term research is required to validate these initial advantages.
Zhila Semnani-Azad, who led the study while completing her PhD in nutritional sciences at the Temerty Faculty of Medicine, University of Toronto, alongside Professor John Sievenpiper stated that when they began the study, intermittent fasting was receiving widespread media attention.
Semnani-Azad is at present, a postdoctoral fellow at the Harvard T.H. Chan School of Public Health, explained that the researchers wanted to explore whether this specific dietary approach offered any added advantages over the more commonly practiced calorie-reduction diets of the time.
The team looked at data from 99 randomized clinical trials with over 6,500 participants to look into this.
The three main forms of intermittent fasting that were the subject of the study were whole-day fasting (eating freely for five days and fasting for two days per week), time-restricted eating (e.g., 16 hours of fasting and eating within an 8-hour window), and alternate-day fasting (eating every other day).
Participants in both groups lost, on average, between 1.7 and 2.5 kilos more weight than those who continued to eat without dietary restrictions, demonstrating that intermittent fasting produced weight loss that was comparable to that of typical calorie-restriction regimens.
According to Semnani-Azad, the evaluation was notable for its comprehensive methodology, which compared different intermittent fasting techniques and assessed weight loss results as well as cardiometabolic health indicators.
Although all three types of fasting yielded comparable long-term results, alternate-day fasting was the only one that led to significantly greater short-term weight loss — with participants shedding about 1.3 kg more than those following traditional calorie-restricted diets.
Those practicing alternate-day fasting also experienced the most notable improvements in several cardiometabolic indicators, such as blood pressure, waist size, total cholesterol, and triglyceride levels. These changes are associated with a reduced risk of developing major health issues like type 2 diabetes and heart disease.
According to Semnani-Azad, the results underscore that intermittent fasting can be a viable and effective strategy for individuals aiming to manage their weight.
“These different weight loss strategies seem to perform similarly,” she added. “It gives individuals a choice to pick the one that is easiest for their lifestyle and for them to maintain in the long term.”
As GLP-1 medications such as Ozempic gain popularity for weight loss, Semnani-Azad hopes this research will offer science-backed alternatives for individuals seeking non-pharmaceutical ways to manage their weight.
Sievenpiper, who is also affiliated with the Banting & Best Diabetes Centre at the University of Toronto indicated that obesity treatment guidelines have shifted away from a universal approach, now placing greater importance on personal values, preferences, and individual goals. He further pointed out that this is particularly relevant in the field of nutrition, where many different strategies offer comparable benefits based on current evidence.
“In showing that intermittent fasting produces similar weight loss and related risk factor reductions as other traditional approaches to calorie-restriction, our findings provide an important opportunity for personalization to achieve the greatest adherence and benefits over the long term.”
As excessive fat becomes linked to more and more health conditions, the findings of the study may offer further guidelines into the various approaches to both manage weight and burn fat.
