The term “intermittent fasting” has become part of everyday vernacular over the past few years. Whether it’s the 16:8 method (fasting for a 16 hour window, eating within the remaining eight), or the 5:2 approach (reducing your calories to around 500 on two days of the week, and eating normally on the other five), time restricted eating—or abstaining from eating during certain hours—is a popular way to manage weight, look after our digestive systems and feel focused, energised, happier and healthier.
But a new study published last week prompted headlines questioning the efficacy of the popular technique—specifically when it comes to weight loss. The study’s aim was to determine whether time-restricted eating proved more effective for weight control in 90 obese (and, it’s worth noting, diverse) adults than calorie restriction, the more traditional method of weight management.
While the time-restricted eating group consumed fewer calories per day than those in the calorie-restricted group, they lost less weight (10lbs versus 12lbs) over the year. The results—which come as a reported 4.3 million people in the UK are living with diabetes—suggest that calorie-counting is a more effective method to achieve and maintain a healthy weight than intermittent fasting. We asked an expert for their take on the study, and on how well the technique actually works.
Calorie counting vs intermittent fasting
“From a scientific perspective—and taking into account my experience from years of clinical practice—intermittent fasting is better for your health than caloric restriction,” says Rhian Stephenson, nutritionist, naturopath and founder of Artah. “But this study points out important themes that are key for overall health, namely the importance of food quality and fibre.”
While the study was an investigation into which diet structure is better for weight loss, there was no focus on—or monitoring of—the quality of the food that the two groups were consuming. Participants were allowed to eat freely and, as Stephenson points out, sugar-free beverages (which disrupt the microbiome) were actively encouraged to help participants keep their calorie intake down.
“Both groups averaged half the daily recommendation for fibre intake, were on fairly high carbohydrate diets, and were ingesting three times the recommended daily allowance for sugar,” she says. “Diet structure will only take us so far, regardless of whether you’re reducing your daily calories or trying intermittent fasting. The most important thing we can do is eat a diverse range of good quality food, rich in fibre and low in sugar. This, in combination with intermittent fasting, will give you the most beneficial change in hormones and set the stage for great health.”
The reality of calorie counting
While we’ve long been programmed to believe that the secret to maintaining a healthy weight is to ensure the number of calories we ingest is equal to the amount of energy we expend, the science world is pivoting to focus on other metrics—think blood sugar levels—for a healthy body (and mind).
This story was originally published on British Vogue.