• In a new study, researchers say intermittent fasting and calorie counting were both effective in helping people lose weight.
• They added that fasting did seem to produce better results for insulin sensitivity.
• Experts say diets affect each person differently, so it’s important to figure out which method works best for you.

Intermittent fasting has become a popular weight loss strategy, but a new study suggests that whether you prefer that or traditional calorie counting methods, both may be equally effective.

Looking at a group of 90 adults with obesity divided into two study groups and a control group, researchers from the University of Illinois Chicago reported that those who engaged in time-restricted eating — also known as “intermittent fasting” — lost an average of 10 more pounds than the control group after a year and consumed an average of 425 fewer calories per day after one year.

The second group, which participated in calorie-restricted eating via calorie counting, lost around 12 more pounds than the control and ate 405 fewer calories daily.

The intermittent fasting and calorie counting groups also received regular consultations with a dietician, whereas the control group did not.

The new research was published in the Annals of Internal Medicine.

“This novel research is immensely encouraging,” said Kelsey Costa, a registered dietitian and health research specialist with the National Coalition on Healthcare, who was not involved in the study. “It highlights that comparable results could be achieved with intermittent fasting or caloric restriction, improving adherence and long-term outcomes. This information is empowering and transformative for those seeking to improve their health and wellness.”

“Calorie counting is not the only way to lose weight and is difficult to sustain long-term,” Dr. Florence Comite, an endocrinologist and founder of the Center for Precision Medicine and Health in New York City who also was not involved in the study, told Medical News Today. “Restricting eating during a shorter ‘eating window’ versus unrestricted eating throughout the day is effective as an alternative. The latter approach may also contribute to optimizing metabolism and hormone regulation through sleep. That’s good news as those outcomes will contribute to optimizing fat loss and muscle gain, with a positive impact on sleep and future weight loss.”

One metabolic difference the study did find with the intermittent fasting group compared to the calorie-restriction group was increased insulin sensitivity, a positive effect of intermittent fasting affirmed by several previous studies.

Experts noted some limitations to this study, mostly having to do with its small size — less than 100 participants — and the fact that it wasn’t a double-blind study, meaning participants knew which weight loss group they were in.

“That does influence outcomes and could introduce bias,” Comite said. “A larger sample size would also provide more statistical power and enhance the findings. Additionally, the duration of the study followed participants for one year, which is a relatively short-term period for evaluating the long-term effectiveness and sustainability of weight loss interventions.”

Experts say one of the benefits of this research is that if the results hold, people don’t have to take a “one-size-fits-all” strategy toward weight loss.

“This is an important consideration,” Comite said. “We are all unique individuals, even identical twins are not the same. A diet or weight loss strategy for one person may not work for another.”

Costa agreed.

“Calorie counting has some strengths regarding aiding weight management, as it allows for precise quantification of calorie intake. By tracking calories, people can ensure they stay within their recommended caloric intake while still getting sufficient nutrition from all food groups,” she explained. “However, the main limitation of calorie counting is that it requires much effort and attention to maintain accuracy in tracking food intake and energy expenditure. Accurately estimating calorie intake can be difficult without specialized food-tracking apps or other tools. This type of precision can be challenging to maintain over extended periods.”

Intermittent fasting, on the other hand, “can produce similar levels of weight loss to that seen with caloric restriction while making adherence easier due to reduced meal frequency, thus providing a more sustainable approach for long-term weight management,” she added.

Having options is good, she said. But having a support network is even better.

Approaching weight loss from an overall health perspective and focusing on positive lifestyle changes is the best way to ensure long-term success,” Costa said. “Building a support system of friends, family, and healthcare professionals who can help you stay motivated and offer guidance and advice when needed is essential, as is setting realistic goals that are specific and measurable will help you keep track of your progress and provide the motivation to stay on track.”