Intermittent fasting is no better than counting calories, study confirms

Restriction is a losing game.

Turns out that restricting the time frame in which you eat is no better than restricting calories when it comes to losing weight.

A new study published in the journal Annals of Internal Medicine found that those who participated in intermittent fasting and ate all of their calories within an eight-hour window lost the same amount of weight as those who ate whenever they wanted but counted calories.

Researchers at the University of Colorado enlisted 90 adults to take part in a trial and divided them into groups.

One group was allowed to eat whatever they wanted but only between noon and 8 p.m.; the second could eat whenever they wanted but restricted their caloric intake by 25%; finally, a control group, whose existing routines were not changed, was monitored against the previous two.

Experimental participants successfully stuck to their assigned diets and did not report any adverse side effects from either.

Compared to the control group, those that restricted calories but did not restrict the time frame consumed 405 fewer calories a day and lost about 12 more pounds on average after one year. Those who participated in intermittent fasting consumed 425 fewer calories per day and lost about 10 more pounds.

Previous findings support the new study, suggesting that calorie counting is still the most effective way to drop unwanted pounds.

“Time-restricted eating (TRE) has become a popular weight-loss regimen,” dietitian and lead study author Shuhao Lin said. “The sudden increase in popularity of TRE is most likely due to its sheer simplicity and the fact that it does not require persons to count calories to lose weight.”

TRE is another name for intermittent fasting, the popular diet trend that celebrities such as Jennifer Aniston, Nicole Kidman, Cameron Diaz and Mark Wahlberg practice.

It involves only eating during a specific time frame, switching between fasting and eating on a regular schedule, according to Johns Hopkins Medicine.

There are two different sub-categories of the intermittent fasting diet. With the 16:8 diet, one would eat for eight hours a day and fast for 16. There’s also the 5:2 diet, which involves eating normally for five days of the week and limiting yourself to one 500- to 600-calorie meal the other two days.

Proponents of the 16:8 intermittent fasting diet believe that it improves control of blood sugar, enhances brain function and increases lifespan.

However, this practice can also lead people to overeat during the eight-hour period, causing them to inevitably gain weight.

There have been many studies that examined the benefits and risks of intermittent fasting.

One study suggests that intermittent fasting could possibly be beneficial for weight loss, while also having a negative impact on reproduction and causing fertility issues.

Researchers also previously found that intermittent fasting did not lead to any more weight loss for obese people than daily calorie caps.

Another study from November 2022 determined that intermittent fasting and skipping breakfast are associated with a higher risk of dying from cardiovascular disease.

Meanwhile, there’s little proof that calorie counting helps shed pounds, according to a top epidemiologist and dietitian in the UK, who says people should focus on the quality of their food instead — though it’s still considered better than intermittent fasting, says a Johns Hopkins University research team.

Regardless, the authors of this specific study believe their findings could be beneficial for intermittent fasting — especially as many people get frustrated and struggle to keep track of every calorie consumed daily, while time restrictions “can sidestep this requirement by allowing participants to simply ‘watch the clock’ instead of monitoring calories, while still producing weight loss and cardiometabolic health improvements,” Lin said.

“Evidence shows that when persons with obesity limit their eating window to six to eight hours per day, they naturally reduce energy intake by 350 to 500 calories,” Lin added. “From a clinical standpoint, these findings are paramount.”

The authors stressed that more research would need to be conducted in order to see who would particularly benefit from these types of diets.