Intermittent fasting has been a buzzy way to lose weight for years, with devotees swearing that eating during a certain window of time has helped them reach their goals and keep excess weight off. But new research has found fasting diets may not be any better than counting calories when it comes to weight loss.
The study is the first in the U.S. to compare the two weight-loss methods head to head, said senior author Krista Varady, a nutrition researcher at the University of Illinois Chicago. Though both yielded similar results, the one that emphasized time instead of calories “is an easier diet to adhere to,” she said.
Those in the second group were given the option to eat whatever they wanted, but the participants had to keep track of their calorie intake and reduce the total they normally ate in a day by 25%.
The third group was the control group – this group did not change its regular eating habits.
“Natural calorie restriction”

Varady’s team recruited 90 adults with obesity (meaning a body mass index over 30) from the Chicago area and randomly assigned them to one of three groups: One group could eat only between noon and 8 p.m., another had to count calories and cut daily energy intake by 25%, and the third group didn’t make any changes to their eating.
Food composition and calorie load distribution are the key
Bhakti Samant, Chief Dietician, Kokilaben Dhirubhai Ambani Hospital, Mumbai, however, feels that all research papers comparing IF and calorie counting do not factor in equally important determinants such as body weight composition and what you should eat. “The research only tells you when to eat and doesn’t tell you what to eat. More than the calories, what matters is the composition of the meal. Without that guidance, most Indians tend to go low on protein and disproportionately seek satiety with more carbohydrates and fat,” she says.
Even Minor Weight Loss Lowers Risks of Diabetes and Heart Disease
Even this relatively small weight reduction can have significant health benefits, according to Dr. Creel, who was not involved in the study. Research from the Washington University School of Medicine in St. Louis has indicated that a 5 percent drop in pounds may lower the risk for diabetes and heart disease, as well as improve metabolic function in liver, fat and muscle tissues.
Fasting doesn’t work for everyone
The fasting group were not asked to count calories but ended up in a calorie deficit by reducing their eating window, so intermittent fasting can be a good way for some people to lose weight. It’s not the first study to find intermittent fasting can lead to weight loss either.
As there was substantial individual variability in weight loss among participants using these interventions, they called for further research to determine who would most benefit from each of these diet choices.
Other health benefits to intermittent fasting

Additional research suggests that intermittent fasting has other health benefits, such as warding off diabetes, heart disease, cancer, and dementia. Intermittent fasting also supports improved insulin sensitivity and reduced inflammation, which can contribute to the aforementioned benefits. Limiting your calorie intake during the first six to eight hours a day can also help stabilize blood glucose levels.
“For some people, it’s just much easier, and hopefully in the long term, they may be able to stick to that plan better than tedious daily calorie counting,” continued Dr. Varady, who specializes in the efficacy of intermittent fasting to reduce weight and metabolic disease in obese adults.