In a society obsessed with thinness and at least the appearance of wellness, it can seem like there's a new "fad diet" popping up every few days or so. Lately, influencers and celebrities alike have been touting the benefits of the metabolic confusion diet — an eating regimen that promises to expedite weight loss by tricking your body into speeding up your metabolism. But like most popular diets, it can be difficult to decipher fact from fiction regarding metabolic confusion and the purported health and weight-loss benefits.

Woman's Day spoke with doctors and nutrition experts to better understand what the metabolic confusion diet actually is, whether or not it's safe, and if it really does work.

What is metabolic confusion?

The metabolic confusion diet, also known as calorie shifting, refers to the concept of alternating your calorie intake between higher and lower amounts. “The thinking behind the metabolic confusion diet is that maybe there’s a way we can confuse the body into not slowing the metabolism down and not increasing appetite,” Dr. Carla Dicenzo-Flynn, a board certified internal medicine physician, nutrition specialist, and founder and director of Metanu Center, tells Woman's Day.

The idea is that by varying the amount of calories your body is processing, you’ll keep your metabolism on its toes and raise your basal metabolic rate, aka the amount of calories your body burns at rest. This in turn will help you burn more calories and promote fat loss.

“The body resists losing weight once you reach your ideal weight,” Dr. Joel Fuhrman, board-certified family physician, seven-time New York Times best-selling author and internationally recognized expert on nutrition and natural healing, tells Woman's Day. “It does this by slowing your metabolic rate, body temperature, respiratory quotient, and thyroid.”

How does it work?

There aren’t a set of strict rules for the metabolic confusion diet. For example, in a two week cycle you could do 11 days of lower-calorie intake, followed by three higher-calorie days. You could also do a one month cycle, where you’d have three weeks of low-calorie days and one week of high-calorie days.

There are no definite guidelines on specific foods to eat while on the diet.

what is metabolic confusion
Unlike many fad diets, people tend to stick to the metabolic confusion diet longer. But like many fad diets, the purported benefits haven’t been proven.
FG Trade//Getty Images

Is it safe?

The diet is probably safe to try if you don’t have any underlying health issues. However, you should always consult a medical professional before starting a new eating regimen, and make sure you’re getting the proper amount of calories for your height and weight.

"If you decide to try any new diet, you should be under the supervision of a doctor, preferentially a specialist in nutrition, who can make sure you are getting adequate nutrients. The amount of calories you require is very individual," Dicenzo-Flynn says. “For example, if someone is 6’5” and eating 1,200 calories on their low-calorie days, that’s basically starvation mode and completely inappropriate.”

What are the benefits of metabolic confusion?

The pros of the diet are that “people who try metabolic confusion may be able to stick with the diet longer and feel more satisfied than those who try to just cut calories alone,” Dicenzo-Flynn says. “However, there is no proof we can confuse our metabolism, and I doubt it is possible. But some people believe those intermittent days where you can eat more make a big difference for them.”

One study compared calorie shifting to calorie restriction, and found that participants of the study reduced their calories (45% less calories in the calorie shifting group, 55% less calories in the calorie restriction group), regardless of whether or not they were trying to "shift" rather than actually reduced them. The calorie shifting group ate as much as they wanted for three days out of every two weeks, while the calorie restriction group ate the same amount every day. While both groups lost weight overall, the study found that the calorie shifting group reported feeling less hungry and more satisfied than the calorie restriction group. In addition, only 15% of the calorie shifting group stopped the study before it was over, compared to 36% of the calorie restriction group.

What are the potential downfalls of metabolic confusion?

The cons of the diet are that speeding up your metabolism could actually have health risks associated with it, and you’d need to stick with the diet to keep the weight off.

“Anything you can do to increase metabolism, such as eating more food or taking metabolic stimulants, will age us faster and be detrimental to one’s health,” Fuhrman explains. “You can’t ‘confuse your body’ to increase metabolism. But what is more important is that there is no benefit to losing weight or using a weight reduction technique, unless you are doing something that is healthful and can be maintained forever. We improve the quality of what we eat and lose weight permanently by eating the healthiest, most nutrient rich foods and eliminating unhealthful high calorie foods. Losing weight is only beneficial if you keep it off forever—that means you have to maintain the healthy diet for the rest of your life.”

The bottom line? It might be easier to stick with the metabolic confusion diet compared to other diets that restrict calories every day, but don’t expect your metabolism to drastically change as a result. You’ll probably be better off focusing on maintaining a health lifestyle by incorporating exercise, nutritious foods, and enough sleep into your daily routine.

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