A recent study from the University of Colorado Anschutz Medical Campus is shaking up the weight loss world with some intriguing findings about intermittent fasting. They compared two groups of people trying to lose weight over a year. One group stuck to a daily calorie restriction, while the other followed a 4:3 intermittent fasting plan. This fasting method lets you eat freely for four days and then cut down calories significantly for the other three days.
The participants were adults aged 18 to 60 with a body mass index (BMI) ranging from 27 to 46. According to the Centers for Disease Control and Prevention, this BMI range classifies them as overweight or obese. After a year, those who tried intermittent fasting lost about 7.6% of their body weight on average, compared to just 5% for the group that restricted calories daily. The study, published in the Annals of Internal Medicine, suggests that 4:3 intermittent fasting might be a little more effective for weight loss.
Danielle Ostendorf and Victoria Catenacci, who co-authored the study, explained the difference between intermittent fasting and time-restricted eating. They pointed out that the fasting method involves alternating between days of significant calorie reduction and days of normal eating. Ostendorf said, “This study shows that 4:3 intermittent fasting is an effective and safe weight-loss approach.”
On fasting days, participants aimed to consume only 400 to 600 calories for women and 500 to 700 for men, which is a significant reduction in their usual intake. These fasting days couldn’t be consecutive, and on the other days, participants had the freedom to eat what they liked but were advised to make healthier choices. “Participants consumed about 400 to 600 calories per day for women and 500 to 700 calories per day for men,” the researchers noted.
The study’s findings align with other research showing that intermittent fasting can be a viable weight loss strategy. However, previous studies on different intermittent fasting patterns like the 5:2 method didn’t show much difference compared to daily calorie restriction. Ostendorf expressed surprise that their results differed, saying, “Once we completed our trial, we were actually somewhat surprised to see that our data didn’t align with these prior published studies of IMF versus DCR.”
The researchers think fasting three days a week might be the “sweet spot” for this type of diet. It’s flexible enough to stick with while still showing results. For those interested in trying out the 4:3 fasting method, Ostendorf recommends starting with just one fasting day and gradually adding more. This allows the body to adjust to the changes in eating patterns.
Both groups in the study worked closely with a dietitian, which may have impacted the results. “All participants in our study received a comprehensive behavioral support program to provide strategies to support them in their weight-loss journeys,” shared Ostendorf. This kind of support might not be available to everyone looking to lose weight, but it was a key part of the study’s setup.
The participants found it easier to consume their limited calories all at once on fasting days rather than spreading them out. The researchers suggested staying hydrated with non-caloric drinks like black coffee or flavored sparkling water. They also acknowledged that more research is needed to ensure the safety of intermittent fasting for other groups, including children, older adults, pregnant women, and those with specific health conditions.
The team hopes to conduct long-term follow-up studies to identify who might benefit most from this approach. In the meantime, they’ve provided a fresh perspective on how intermittent fasting might fit into the broader picture of weight loss strategies. This study opens up new possibilities for those struggling with traditional dieting methods and looking for alternatives that could work better for them.
