A recent U.S. study has revealed that a simpler weight loss strategy may outperform traditional daily calorie restriction. Researchers have found that the 4:3 intermittent fasting method — where individuals restrict their calorie intake three days per week and eat normally for the remaining four — resulted in greater weight loss over the course of a year.
Conducted by a team from the University of Colorado, the year-long study involved 165 adults aged 18 to 60 who were either overweight or obese. Participants were split into two groups: one followed the 4:3 intermittent fasting (IMF) schedule, and the other adhered to a daily calorie restriction (DCR) plan. Both groups were also advised to increase their physical activity.
On average, participants in the intermittent fasting group lost 7.7 kg (about 17 pounds), while those in the daily restriction group lost 4.8 kg (about 11 pounds). While the difference may seem modest, researchers emphasized the significance of the findings. “It was surprising and exciting to me that it was better,” said endocrinologist Dr. Victoria Catenacci, who led the study. The research suggests intermittent fasting may be more sustainable and appealing to people who struggle with constant calorie tracking.
Adherence and Simplicity: Key Advantages of the 4:3 Intermittent Fasting Approach
The IMF method requires participants to cut 80 percent of their calorie intake on three non-consecutive days each week, with no specific restrictions on the other four days — though a healthy diet is still encouraged. In contrast, the DCR group was expected to maintain a consistent 34 percent calorie reduction every day.
Researchers believe that part of the IMF group’s success may be attributed to better adherence. The fasting schedule may have been easier for participants to follow, making the program more manageable in the long term. This was further supported by self-reported food diaries, although the researchers acknowledged potential inaccuracies in tracking, especially on non-fasting days.
Despite the self-reporting limitations, health benefits were noted in both groups. Participants saw modest improvements in blood pressure and other metabolic markers, adding to the growing body of evidence that intermittent fasting can support general well-being in addition to weight loss.
Dr. Catenacci emphasized that the study presents intermittent fasting as a viable, evidence-backed option for individuals who find traditional calorie counting too rigid or difficult. “This is a dietary strategy that is an evidence-based alternative,” she said, particularly for those who have not seen success with other methods.
Future of Intermittent Fasting: Toward Community-Based Programs
While the results show promise, researchers also noted that structured, widely available programs for 4:3 intermittent fasting currently don’t exist. Physical activity epidemiologist Danielle Ostendorf expressed interest in developing practical models for clinics and community settings.
“I want to work on how to design this for implementation in clinics and community programs that are accessible to people and make this something that they can afford,” said Ostendorf.
As obesity rates continue to rise globally, the need for accessible, personalized, and effective weight loss strategies becomes more urgent. The findings, published in the Annals of Internal Medicine, mark a step forward in identifying simpler alternatives that can help more people achieve lasting results without the constant pressure of daily calorie restrictions.
