We’ve all heard stories about people dropping crazy weight and then putting it all right back on. Case in point: A certain canceled television challenge show in which participants made incredible progress, losing tens—if not hundreds—of pounds only to rapidly regain weight after returning to real life. This struggle is also one that many bodybuilders know well after spending months whittling their bodies down in preparation for competitions. (I’ve even heard of people gaining 50 pounds in a month post-contest!)

Indeed, research shows that less than 20 percent of dieters are actually successful in maintaining their weight loss for at least one year. There are numerous reasons for this—and the roots of the issue can be a mix of physiological, mental, and emotional factors. 

Don’t worry, I’ll save everyone a full dissertation on the topic. For now, let’s chat about one key physiological reason why it’s so easy to regain weight. Once we have that understanding nailed down, we can dig into a concept designed to combat this weight gain rebound: reverse dieting. Here’s what you should know.

Metabolic Adaptation, A Key Culprit Behind Weight Regain

When someone undertakes a diet, they’re almost certainly going to find themselves in a calorie deficit. This calorie deficit refers to the chasm between the amount of energy you eat and the amount you expend. The difference between the two is a massive driver of weight loss; if you burn more than you eat, you have to call upon reserve energy stores to maintain homeostasis. What are those reserve energy stores? Body fat!

However, body fat plays a few roles in our body, and one of them is that it sort of constitutes our body’s “safety net”. We store additional calories as fat in order to save this energy for later use. This way, just in case we go days or even weeks without food, we’ll have something to burn for energy to keep fueling everyday living. Virtually every animal on the planet exhibits a similar process, but humans in developed countries are the primary species able to consistently overeat to the point of gaining noticeable fat.

Read More: 5 New Approaches To Burning Fat And Getting Shredded

When we diet and consume fewer calories, our metabolic processes adapt over time. First, eating less food automatically results in less energy expenditure (a.k.a. we start to naturally burn fewer calories). From there, actually losing weight then automatically leads to reduced energy expenditure. And finally, consistent consumption of a calorie deficit over time enhances our metabolic efficiency, which is ultimately the exact opposite of what we want on a diet. Think of a fuel-efficient car. It doesn’t require much fuel to travel a certain distance, right? If you’re trying to lose weight, you want to be inefficient; the more fuel you burn, the more weight you lose!

All of these processes work together to slow your metabolism down over time. In fact, research has shown that low-calorie diets (and the associated weight loss) can reduce your daily calorie burn by nearly 20 percent.

So, what happens once your diet is over and you hop back on your previous eating plan? At a minimum, you’re immediately consuming a 20-percent calorie surplus. All aboard the weight-gain train! It’s a pretty devastating realization, which means you’re probably wondering: What can you do to avoid this dieting pitfall?

Enter Reverse Dieting

The answer to your question: reverse dieting. In a reverse diet, you purposefully plan out a diet that systematically leads you back to your pre-diet calorie intake. The idea here is to avoid immediately overloading your metabolism and packing weight right back on. However, there are a few tricks to optimizing a reverse diet. 

First, minimize further metabolic adaptation

This might seem counterintuitive at first, but the number-one mistake people make on a reverse diet is to carefully add a handful of calories back into their diet every few days, thinking it will help them avoid rebound weight gain. Well, guess what? All this time, they’re likely still in a calorie deficit, thus expanding the extent of their metabolic adaptation and wasting their efforts.  In fact research on professional natural bodybuilding showed that slow reverse dieting did not prevent fat gain, and that healthy hormone levels were not reestablished until the competitor returned to their normal calories. That’s why I’m a proponent of the exact opposite: getting your calorie intake back to maintenance levels immediately. How you do that, though, is where a little strategy comes in.

Key Reverse Dieting Tactics

1. Go in on protein

To jump back up to maintenance calories, try to increase your energy intake primarily through protein. It is extremely metabolically costly to store protein as fat, so our bodies don’t even bother doing it. In fact, studies have shown that overeating with protein actually enhances fat loss. A number of quick tweaks can help you up your protein intake—and, of course, you can always turn to a protein powder to pack in more grams. I recommend whey, casein, egg, or another animal-based protein. (We recently conducted a study that found that whey, chicken, and beef protein all enhanced body composition.)  For best results, incorporate at least one to two servings (about 20 to 40 grams) of a protein powder per day when coming out of a long-term diet.

2. Exercise in a fasted state

Studies have actually shown that, during a period of overfeeding, fasted exercise can blunt weight gain by 50 percent compared to exercising in a fed state. One of the easiest ways to do this is to simply exercise right after waking up in the morning. This way, you can start eating again right after your workout. We don’t fully understand why this might be the case, but improvements in nutrient sensitivity and greater acute energy debts might play a role.

3. Perform high-intensity exercise

Studies have also shown that high-intensity exercise can effectively combat the negative effects of an energy surplus diet. However, a large part of this effect is likely due to the high-intensity exercise increasing your activity calories. Therefore, you might not actually be in a true calorie surplus, which could impair your metabolic re-adaptation. So, go for higher-intensity resistance training over intense cardio or interval training to best support your goals here.

The Bottom Line

Because of metabolic adaptation, gaining some weight after a diet is almost inevitable. However, with a proper reverse diet (immediate calorie rebound, high protein intake, fasted exercise), you can combat it effectively. Moreover, I’m a huge advocate of resistance training throughout this time period, especially if you’re not currently lifting weights. Once you get back into a calorie surplus, lifting weights can help gear your body towards gaining muscle, rather than gaining fat. Since gaining muscle still likely requires a calorie surplus, your reverse diet period is a great time to start lifting weights if you don’t already.

Coming out of a diet is difficult—but these strategies can help you successfully stay lean. I recommend carefully adhering to them for at least three months following intense dieting.  After that, shift your focus to muscle gain, more fat loss, or maintenance. 

Hopefully, understanding the ins-and-outs of reverse dieting will help you implement it strategically into your own nutrition and fitness routine in order to hang onto results. 

Known as ‘The Muscle Ph.D.,’ Dr. Jacob Wilson has a knack for transforming challenging, complex concepts into understandable lessons that can support your body composition and health goals. A skeletal muscle physiologist and sports nutrition expert, Wilson is a leader in muscle sports nutrition. As the CEO of The Applied Science & Performance Institute and researches supplementation, nutrition, and their impact on muscle size, strength, and power.