Metabolic Confusion: Why You Can’t Outsmart Your Metabolism

On another journey into the darkest recesses of the Internet, I came across something called the metabolic confusion diet.

Fans of the diet claim that it confuses your metabolism, which keeps it running faster than normal. This in turn will lead to more calories being burned and more fat being lost.

What is metabolic confusion all about? And is it really going to help you lose fat faster?

What is Metabolic Confusion?

The metabolic confusion diet involves alternating between high- and low-calorie days. On a low day, for example, you might consume 1200 calories. On a high day, it might be somewhere in the region of 2000 calories.

The idea is that by varying your caloric intake (AKA calorie cycling), you’ll boost your basal metabolic rate (the number of calories your body burns at rest just to keep you alive), as well as altering the levels of various hormones such as leptin and ghrelin, all of which is supposed to help you avoid hitting a weight loss plateau.

From what I can tell, there are no rules for the metabolic confusion diet.

You might follow a diet that puts you in a calorie deficit, and add in 2-3 high-calorie days every couple of weeks.

You might have two weeks of higher calories and two weeks of lower calories, where you stay in a calorie deficit the whole time. Or you might have one high-calorie day each week, with the rest of the time spent eating fewer calories than normal.

Does Metabolic Confusion Work?

Your metabolism can certainly adapt to changes in your diet. Sensing a reduction in food intake, your body turns down the rate of heat production in order to conserve energy.

However, the idea that you can confuse your metabolism is complete nonsense.

In fact, research comparing continuous calorie restriction with diets that involve alternating between higher and lower calorie intakes show little difference in weight loss between the two.

In one study, a group of overweight or obese young women was assigned to either a standard or an intermittent fasting diet [1].

Twice a week, the fasting group reduced calories to just 25% of their daily calorie needs. On the other five days, they increased their calorie intake to the level required to maintain their weight.

Continuous dieters, on the other hand, followed a more restrictive diet that involved cutting calories by the same amount each day. 

If switching between high and low calorie intakes somehow led to metabolic confusion and a faster metabolism, you’d expect to see a faster rate of fat loss in the calorie cycling group. 

But that isn’t what happened.

After six months, there was no significant difference in the amount of fat lost between the two groups.

In a follow-up trial, researchers at the University of Illinois at Chicago compared a continuous calorie restriction diet with alternate day fasting (i.e. cycling between high and low calorie days) [2].

After six months, both groups of dieters had lost roughly the same amount of body fat. Going from a high calorie day, to a low calorie day, to a high calorie day and so on, was no better for fat loss than continuous dieting.

The Benefits of Calorie Cycling

That’s not to say there are no potential advantages to calorie cycling.

If the metabolic confusion diet works in a similar way to intermittent fasting, it may have other benefits beyond just weight loss.

“Intermittent fasting-type diets can improve your ability to manage fuels in the body – known as metabolic flexibility,” says Dr Adam Collins, a nutrition expert at the University of Surrey.

“Metabolic flexibility means you’re better at burning and storing carbohydrates when you need to, and equally better at managing the storage and release of fat from fat stores. This improves insulin sensitivity, which reduces overall risk from disease, such as cardiovascular disease and diabetes. All of this is independent of weight or weight loss.”

However, when it comes to weight loss, any benefits of calorie cycling has a lot more to do with an increase in dietary compliance than it does changes in your metabolic rate or leptin levels.

For example, there was a trial published some years back, which compared regular calorie restriction with a calorie shifting diet [3].

Calorie shifting is just another term for calorie cycling. This particular variation involved 11 days of calorie restriction, followed by three days where participants were allowed to eat what they wanted.

The result?

After six weeks of dieting, there was no significant difference in the amount of fat lost between the two groups. Whether they cycled their calories or followed a more restrictive diet, the end result was much the same.

For the next 4-week cycle, participants were told to eat a slightly higher level of calories. The aim here was to maintain their body weight. There was no calorie cycling, and both groups were told to eat the same amount of calories each day.

During this month-long weight maintenance cycle, the calorie cycling group managed to keep the weight off. Regular dieters, on the other hand, gained back 50% of the fat they’d lost.

The results also show a bigger drop in resting metabolic rate in the regular dieters compared to the calorie cycling group, which is why this study is often used to support the idea that calorie cycling protects your metabolism during weight loss.

However, the difference in resting metabolism between the two groups of dieters wasn’t sufficient to explain the lower rate of fat regain in the calorie cycling group.

Instead, it likely had more to do with improved dietary compliance than any metabolism confusion. 

The calorie cycling group reported feeling less hungry and more satisfied than the calorie restriction group. In addition, 14 of the 37 women in the calorie restriction group dropped out of the study. That’s more than twice the number who dropped out of the calorie cycling group.

This goes a long way towards explaining why the regular dieters gained back more of the lost body weight. Being told that you can eat just 1200 calories a day for six weeks, when you’re used to eating double that amount, will invariably lead to some kind of backlash once the diet is over.

Metabolic Confusion Diet Plan

Diet plans designed around the idea of metabolic confusion can be a very effective way to lose weight. But that’s not because they confuse your metabolism. 

Rather, it’s because alternating between higher and lower calorie intakes allows for some flexibility and freedom in your diet, which in turn makes it easier to stick with that diet long enough to reach your goal.

Let me show you what I mean.

When designing any meal plan, the first step is to calculate how many calories you should be eating.

While this method for estimating what your calorie intake should be isn’t 100% accurate (no method is), it does give you a rough idea. You can then adjust and tweak this number over time based on how your body responds.

1. Take your bodyweight in pounds and add a zero to the end.
2. Multiply that number by 7 to obtain your total weekly calories.

For example, if you weigh 200 pounds, your average calorie intake should be around 2000 calories per day. Over the course of the week, that comes to 14,000 calories.

To repeat, this number is just an estimate, and will need to be adjusted over time as weight is lost. But it’s a quick and simple way to get you started.

In theory, your diet plan would look like this:

• Monday: 2000 calories
• Tuesday: 2000 calories
• Wednesday: 2000 calories
• Thursday: 2000 calories
• Friday: 2000 calories
• Saturday: 2000 calories
• Sunday: 2000 calories

TOTAL = 14,000 calories

But let’s be honest, who’s going to do that? Who’s going to eat the exact same number of daily calories from one day to the next for any length of time? I’m not, and you’re probably not either.

This type of rigid meal plan can work in the short term. But such a monotonous diet is probably not going to work in the long term. It’s just not a good fit for the way most people live their lives. 

But if you know how many calories you should be eating over the course of the week, you can adjust your daily calorie intake from day to day. As long as you stay within your calorie budget for the week, you’re going to lose fat.

For example, you’re going out for dinner on Saturday night, and you know that you’re going to end up eating more than 2000 calories that day. 

Rather than choose something from the boring “diet menu” that you don’t really want, or skip dessert, the extra calories can simply be pulled in from other days. This way, you get to enjoy a night out without feeling guilty that you’re messing up your diet.

Here’s what it might look like:

• Monday: 2000 calories
• Tuesday: 2000 calories
• Wednesday: 1000 calories
• Thursday: 2000 calories
• Friday: 2000 calories
• Saturday: 4000 calories
• Sunday: 1000 calories

TOTAL: 14,000 calories

You’re still eating the same amount over the course of the week, but you’re switching between a high- and low-calorie intake. That gives you more flexibility and choice about what and when you eat.

Here’s another example of the type of thing I mean.

Let’s say you do regular exercise three days per week, on Monday, Wednesday and Friday. You want more energy for your workouts, and decide to eat more on the days you train. In which case, your meal plan might look something like this:

• Monday: 2500 calories (high carb day)
• Tuesday: 1500 calories (low carb day)
• Wednesday: 2500 calories (high carb day)
• Thursday: 1500 calories (low carb day)
• Friday: 2500 calories (high carb day)
• Saturday: 1500 calories (low carb day)
• Sunday: 2000 calories (moderate carb day)

TOTAL: 14,000 calories

Again, your total calorie intake over the course of the week is the same, but you’ve done so by alternating between a high- and low calorie intake. It makes for a far less monotonous diet and more sustainable lifestyle.

Some days are low-carb days, one or two might be high-carb days, while the rest are somewhere in the middle.

To repeat, these diet plans have nothing to do with metabolic confusion. They just make it easier to be consistent with your diet, which is the real key to losing weight and keeping it off in the long-term.

Irrespective of how many calories you’re consuming on any given day, it’s important to make sure you’re getting enough protein in your diet.

In other words, you don’t want to cycle your protein intake. Keep protein intake static from one day to the next, and adjust the level of carbs and fat in your diet.

The reason why is that protein has a couple of important roles to play when it comes to weight loss.

First, it helps to preserve muscle mass while you drop fat. Without adequate amounts of protein, you’ll end up losing muscle as well as fat.

Protein also does a better job at filling you up than carbohydrate or fat, making it easier to control your hunger.

That protein can come from whole foods, such as chicken, tuna or turkey, or a few high-protein snacks (i.e. a protein shake or bar). In many cases, the addition of 1-2 protein-rich snacks to your regular diet is an easy and convenient way to get the extra protein you need.

In total, your daily protein intake should be around 0.7 grams of protein per pound (1.6 grams per kilogram) of bodyweight.

There’s no good reason why your protein intake can’t be higher. If anything, I’d lean towards eating a little too much, rather than not enough. But in most cases, 0.7 grams of protein per pound of body weight will be enough.

The Metabolic Confusion Diet and Endomorphs

For reasons that remain mysterious, the subject of metabolic confusion seems to be closely linked to the so-called endomorph body type.

That is, when I search for metabolic confusion, these questions appear in the “people also ask” results:

• How do endomorphs lose weight?
• What are the 3 types of metabolism?
• What foods should an endomorph eat to lose weight?

From what I can tell, having an endomorph body type – a large bone structure, sometimes referred to as fat or chunky – supposedly makes you the perfect candidate for metabolism confusion.

Here’s how one article describes it:

“Creating metabolic confusion through a carb cycling plan is the best way to help endomorphs lose weight. With constant alterations in the level of carbs in the body, the creation of confusion in the body’s metabolism can help endomorphs tackle carb insensitivity and deal with slower metabolisms in a much more efficient way.”

The whole idea that your body type can be used to determine what diet you should follow is complete nonsense.

Nobody cites any studies or evidence to support the claim that endomorphs are better suited to a metabolic confusion diet, because there isn’t any. 

It’s completely fictitious nonsense, which has been made up on the spot, or copied and pasted from someone else.

This thing happens a lot in the fitness and diet world.

Guru A makes a statement.

Guru B repeats that statement.

Then it’s parroted by someone else further down the guru line of command.

Said statement has now taken on the appearance of a fact, simply because there are so many people claiming that it’s true.

Recommendations that a mesomorph should eat this or an endomorph should eat that are perfect examples of Barnum statements: the advice is so vague and general that it could apply to anyone.

RELATED: The Great Body Type Myth: Why Somatotypes Don’t Matter

Final Thoughts

Calorie cycling, particularly when it involves ramping up your carb intake, does have a number of benefits. It gives you a mental break from the grind of dieting, you have more energy, you perform better in the gym, and you just feel a whole lot better.

However, there’s very little evidence to show that calorie cycling has any significant impact on your resting metabolism. And even if it did, the extent to which changes in metabolic rate contribute to fat loss is relatively small. 

While you might find it easier to stick with a diet that involves some kind of calorie cycling, don’t expect your metabolism to change dramatically as a result.