As for weight-loss plans, it’s easy to see the appeal of intermittent fasting: Eat whatever you want, but only during certain time periods — often just eight hours a day.
Instead of counting calories or measuring portions, dieters should simply pay attention to the clock, said Courtney Peterson, a nutrition researcher at the University of Alabama at Birmingham.
“It’s a very simple rule for you: Eat or don’t eat,” Peterson said.
The popularity of this technique has increased a lot in the recent years and it has become a major trending topic on social media.
But does time-restricted eating, which is a form of intermittent fasting, actually help people lose weight and boost health?
Here’s what you need to know about this exercise:
Also read: Intermittent fasting increases risk of death from heart disease by 91%: Study
What is intermittent fasting?
Peterson said intermittent fasting is an eating strategy in which people switch between fasting and eating on a regular schedule, defined as going at least 14 hours without food. This could mean eating every other day, eating five days a week and then fasting for two days, or restricting daily eating to a few hours.
Time-restricted eating, in which people limit all their eating to a daily period of 10 hours or less, is the most popular form of intermittent fasting. People on the diet will delay breakfast until 10 a.m. or noon and then eat dinner until 6 p.m. or 8 p.m., abstaining from food for the rest of the time.
How will this help?
The theory behind time-restricted eating is that it supports circadian rhythms, or the body’s internal clock. For example, scientists say that spending more time in a fasted state may boost the body’s processes that regulate blood sugar and fat metabolism.
Initial studies on rats in 2012 showed that time-restricted eating offered health benefits. Smaller studies on obese people showed that the practice could help them lose weight and improve other health indicators.
Is time-restricted eating effective for weight loss?
Research has shown that people on time-restricted eating plans eat fewer calories, which may be one reason for weight loss.
Results from the combined studies showed that obese adults who restricted their eating hours, regardless of calorie intake, naturally reduced their energy intake by 200 to 550 calories per day, which translated into a 3% to 5% reduction in their baseline body weight.
But a large study of people over a long period of time found that time restrictions alone don’t make a difference.
A 2022 study published in the New England Journal of Medicine tracked 139 people with obesity for a year. Participants either followed a calorie-restricted diet during a certain time period or consumed the same number of calories throughout the day. Both groups lost an average of 14 to 18 pounds — but there was no significant difference between the strategies.
“Our data show that eating within a time limit is no better or worse than restricting calories,” Peterson said, adding that the technique doesn’t help you burn more calories.
Still, Peterson said the simplicity of a time-restriction regimen may be easier to maintain than a normal diet.
“Almost nobody likes counting calories,” he said.
Is intermittent fasting safe?
Preliminary clinical trials with six- to 10-hour eating periods found that time-restricted eating was “generally safe,” the researchers reported in the journal Obesity.
But a headline-making study presented at the American Heart Association’s Scientific Sessions this year found that people who followed an 8-hour time-restricted diet had a much higher risk of death from heart disease than those who ate for 12 to 16 hours.
Dr. Francisco Lopez-Jimenez of the Mayo Clinic pointed out that this research has not been published in a peer-reviewed journal.
But he said there is reason to be cautious. Long-standing evidence shows that skipping breakfast can lead to cardiovascular disease and death. People should check with their health care providers before embarking on a restricted diet, especially if the fast lasts until the afternoon.
“One should pause for a bit before recommending any specific diet,” Lopez-Jimenez said.
