New research suggests that the calories you eat may be more important than when you eat when it comes to weight loss.
Specifically, researchers found that people who followed a time-restricted diet lost the same amount of weight as people who ate the same diet without a time limit.
The research results are Annals of Internal Medicine, challenge yourself with the efficacy of intermittent fasting or time-restricted eating (TRE), a popular weight loss method that narrows your eating window to a specific window. Proponents promote this strategy as an easier way to lose weight than old-fashioned calorie counting.
Previous studies have linked time-restricted eating with weight loss, but the mechanisms behind the success of this strategy remain unclear. A new research team wanted to investigate whether time-restricted eating could induce weight loss regardless of the number of calories a person consumes.
The authors concluded that this was not the case and suggested that “the effects of TRE on body weight in previous studies may be due to reduced caloric intake, given the short duration of intake.”
Scientists recruited 41 adults with obesity and pre-diabetes, most of whom were black women. They provided meals for two weeks based on individual needs.
Half of the participants were instructed to consume all their food within 10 hours, with 80% of calories consumed before 1 p.m. The other group followed a more traditional eating plan. They ate for over 16 hours and consumed more than half of their calories. After 5pm
Participants in both groups consumed the same daily calories and the nutritional composition of their meals was similar.
After three months, scientists found that participants in both groups had lost about the same amount of weight. People in the time-limited group lost 5 pounds, while people in the other group lost 5.7 pounds. Both groups experienced similar changes in heart health measures such as blood sugar and blood lipid levels.
“This reinforces the importance of sticking to a calorie-restricted diet when trying to lose weight,” says Vanessa Imus, MS, RDN, a registered dietitian and weight loss expert in Bothell, Washington. health. “Whether you want to track calories or limit meal times, they are equally effective as long as they help lower your overall calorie intake.”
Imus added that the data “challenges some of the previous research on meal times that concluded that eating more calories during the day is always better for weight loss than eating more calories later in the day.”
“There is good reason to draw strong conclusions from this study,” said study author Nisa M. Maruthur, MD, associate professor of medicine at Johns Hopkins University. [the] “Results,” she said, acknowledging that the study included a small sample size.
Additionally, most participants were black women, meaning the results may not apply to other groups.
The researchers also provided the participants with prepared meals, which “may be very different from how they typically eat when adopting a time-restricted eating pattern or a calorie-deficient diet,” Imus explained.
Before starting a new weight loss plan, it is best to consult with your health care provider to develop a strategy for balancing weight loss and health.
For example, if you're considering cutting calories, your health care professional can help you calculate how many calories you need based on your unique situation, such as your body size and level of physical activity. That way, you don't risk eating too few calories, which can make you feel weak and lead to health problems over time, such as decreased immune function and an increased risk of developing chronic diseases.
It's also a good idea to consider your lifestyle and interests when choosing a weight loss method.
Research suggests calories are more important than timing, but that doesn't mean time-restricted eating isn't the right plan for you. Anyone struggling with irregular eating patterns or looking for a clear, manageable eating framework may find this strategy particularly useful.
“It goes back to the idea that the best diet is one you can stick with,” Maruthur said.
And keep in mind that calorie counting and time-restricted eating aren't your only tools for weight loss. Other ways to stay slim include eating more fiber-rich foods, exercising more, limiting processed and sugary foods, and getting enough sleep.