If you've recently lost weight or been dieting for a while, you may have noticed that the closer you get to your goal, the harder it is to lose fat. You might even feel like you're doing everything right, but your body has other plans. Instead of dropping more pounds, you may start gaining weight again. And the only thing that seems to fix the problem? Eating more. This is where reverse dieting comes in. In a nutshell, reverse dieting increases your calories after a diet to help restore your metabolism and maintain your results. But how long does reverse dieting take? The answer isn’t straightforward, but this article will help you understand how to rebuild your metabolism, maintain a leaner physique, and eat more food without regaining fat, all in the shortest healthy timeframe possible.
Calorie tracking can help. Using Cal AI’s calorie tracker can help you achieve your reverse dieting goals by providing structure and helping you stay on track as you increase your food intake.
Reverse dieting is a structured method of gradually increasing calorie intake after dieting or restriction. The main goal is to rebuild metabolism, prevent rapid fat gain, and help the body adjust to higher caloric intake in a controlled way.
After a diet, your body is not the same as it was before the diet. It has adapted to the caloric restriction, and slowly increasing calories can help restore metabolic function and hormonal balance.
Successful, long-term weight loss is a challenging goal for many people. While many lose weight, maintaining that loss is often a struggle. Studies suggest that most people who lose over 10% of their body weight regain it within 2 years.
After putting so much time and effort into weight loss, it makes sense that people are searching for ways to prevent weight regain. This could be why the trend of reverse dieting has become popular. The belief is that a slow return to regular eating patterns, after a period of calorie restriction, will give your body time to adjust to a higher calorie intake, minimizing weight regain. Reverse dieting involves slowly increasing the calories you eat after following a restricted diet. The goal is to avoid weight gain by quickly returning to a regular eating pattern.
Research has shown that a calorie-restricted diet lowers your metabolism and resting metabolic rate. Your body slows down to preserve its energy. This means that quickly returning to a more normal eating pattern may lead to rapid weight gain if your metabolism remains slow.
The idea behind reverse dieting is that a slow reintroduction of calories gives your metabolism time to adapt. As you gradually increase your calorie intake, your metabolic rate slowly increases, minimizing weight regain.
Reverse dieting is a tactic that bodybuilders often use to prevent gaining body fat after a competition. These athletes usually follow high-protein, low-calorie diets before a competition to fit into specific weight categories, increase muscle mass, and maintain as low a body fat percentage as possible. After their competition, many slowly increase their carbohydrate and fat intake weekly. They do this in hopes of restoring a normal balance and slowly regaining weight while preserving their muscle mass.
Your metabolism can slow down when you’ve been on a low-calorie diet. This phenomenon, called “metabolic adaptation,” is believed to happen for several reasons.
For example, the hormone leptin helps determine how many calories you burn. Calorie restriction decreases leptin levels, lowering the amount of energy (calories) you use.
Reduced-calorie diets may also lower insulin and increase ghrelin and cortisol, which increase appetite. Low-calorie diets may also decrease thyroid hormones, slowing the overall metabolic rate.
All movement burns calories, including unconscious activities like tapping your foot or drumming your fingers. The calories this sort of fidgeting burns are part of nonexercise activity thermogenesis, or NEAT.
NEAT takes up about 15% of your daily energy use. During calorie restriction, you may subconsciously stop fidgeting, and this number may drop.
Mitochondria are like little batteries in your cells that produce energy. Usually, they leak subatomic particles called protons during this process. This “proton leak” causes you to burn more calories. When you’re eating a low-calorie diet, your mitochondria are more efficient and leak fewer protons. This, in turn, means that you burn fewer calories.
Metabolic adaptation isn’t necessarily temporary. A study looked at contestants 6 years after they appeared on the weight-loss television show “The Biggest Loser.” Many still had the low metabolisms they developed during the show, even when they’d regained their weight. The theory behind reverse dieting is that you slowly increase your calories by 50 to 100 a week to a maintenance level to allow your metabolism to return to “normal” and avoid “The Biggest Loser” dilemma. While metabolic adaptation is grounded in hard science, reverse dieting science is much thinner.
There’s little scientific evidence to support reverse dieting, but it might be helpful for some to work toward a sustainable eating plan. Anecdotal reports and some research on refeeding in athletes indicate there may be some physical and mental benefits as well, including:
Of course, many factors affect how successful someone will maintain weight loss. Some of the most promising results in weight maintenance include focusing on behavior changes. People who can maintain weight loss are more likely to adopt a variety of healthy lifestyle behaviors, including:
There’s no one-size-fits-all answer to how long reverse dieting takes. Everyone’s body is different, and factors like how long you’ve been dieting, how aggressive the diet was, how much weight you’ve lost, and your unique metabolic rate all contribute to how long reverse dieting will take.
In general, reverse dieting can last from a few weeks to several months. If you’ve been on a particularly aggressive diet for a long time, you may want to consider reverse dieting for several months to fully allow your body to adapt to the changes.
This all sounds a little hocus pocus abracadabra. Bear with us. There’s some science to back this all up, but before we can cover the concept of reverse dieting, we must cover the idea of energy balance. Simply put, you gain weight when you eat more energy (calories) than you burn.
When you eat less energy than you burn, you lose weight. Many people know this concept by another name, calories in, calories out (CICO). Some people only debate whether CICO and energy balance are valid because they misunderstand a key point.
The energy balance equation is simple, but as you can see below, many factors affect energy in and out. These factors go way beyond food and exercise. Factors people often overlook, such as food absorption, stress, genetics, and metabolic adaptation (described below), can tip the energy balance “scale” in either direction.
Reverse dieting works through one of the factors that can impact energy balance: metabolic adaptation. One type of metabolic adaptation is known as the body’s “starvation response.” (This is different from the fabled “starvation mode,” which isn’t really a thing.)
Obesity is a global health issue now, but it wasn’t always that way. On the other hand, starvation has been a real threat to humankind for hundreds of thousands of years. So when you eat less, your body instinctively starts preparing for famine in several ways:
That’s the amount of energy you need to live when at rest. This reduces energy out. Exercise becomes more difficult because you have less available energy. (If you’ve ever tried an intense workout on a low-calorie diet, you know what we’re discussing.)
So you’re likely to burn fewer calories through activity. You also expend less energy through exercise because, as your body gets smaller, it doesn’t require as much fuel, and your metabolism also adapts to make you more efficient. This also reduces the number of calories you burn through movement, resulting in less energy out.
Daily activity outside of workouts (think: pacing while you’re on a phone call, walking to your car, fidgeting) lessens, resulting in reduced energy out from non-exercise activity thermogenesis (NEAT). Digestion slows, so your body can absorb as many nutrients as possible, increasing energy intake.
Because of this adaptive response, someone who has dieted down may need 5 to 15 percent fewer calories per day to maintain the same weight and physical activity level as someone who has always been that weight. And if someone’s lost an extreme amount of weight? The percent drop in calorie needs becomes more extreme, too. (Hey, no one ever said diets were fair).
The silver lining? Metabolic adaptation works both ways. If you increase your calories gradually, your body will adapt in the other direction. This phenomenon is called adaptive thermogenesis, which means your body wastes calories as heat.
When done correctly, reverse dieting provides several metabolic benefits:
But to get this effect, it’s essential to add calories slowly. That’s primarily because the body seems to respond differently to varying rates of “overfeeding.” (That’s the word researchers use to describe eating beyond your calorie needs.)
In one study, eating 20 percent above maintenance calories did not significantly increase fat gain, whereas eating 40 to 60 percent above maintenance did. In other words, if you maintain your weight on a 2000-calorie diet, you can eat up to 400 extra calories a day without significantly impacting the scale. But an additional 800 daily calories? It’s probably going to weigh you down.
Some data suggest that the time people need to “recover” from dieting is roughly proportional to how much they spent dieting. So if you restrict calories for six months, you may need to give your metabolism six months to adjust. This is just one of the many reasons.
Reverse dieting has gained miracle status in some corners of the internet as a way to eat more to lose weight. This makes it seem like reverse dieting flies in the face of the energy balance equation and the laws of thermodynamics.
This is not the case. Can you lose weight while reverse dieting? Yes. But it’s still always because increased “energy in” results in increased “energy out.” In our experience, reverse dieting can work, but not for everyone, in the same way, in all conditions, 100 percent of the time.
There are three important caveats to acknowledge here.
As much as we’d like to think people are spreadsheets and that all of this comes down to simple math, there’s much variability from person to person. Here’s an example: In one study conducted at the Mayo Clinic, researchers brought 16 normal-weight people into a lab for eight weeks.
They served them huge meals that provided 1,000 extra calories each day. That’s the equivalent of eating about two double cheeseburgers daily on top of your usual noshing. Plus, the participants were instructed not to exercise. If you do calorie math, everyone should have gained 16 pounds in eight weeks.
They gained anywhere from under one pound to about nine pounds. What is the most significant predictor of adaptation or gaining less weight? Increased NEAT. Some people’s weight barely changed, and some people's weight barely changed. Others had much more modest increases, and they ended up gaining more.
In reverse dieting, the hope is that your body and metabolism will adjust via NEAT and other mechanisms. The degree of adjustment, and whether any adjustment happens at all, varies from person to person.
“Wow, I can keep eating more and more and never gain weight?!” said no post-menopausal woman ever. All jokes aside, metabolism naturally declines with age. Unless you strength train consistently, you lose five to 10 pounds of metabolically active muscle per decade from 25 to 30.
That continues linearly. So, the exact reverse dieting protocol that worked for a 20-year-old will not work like when they’re 40 or 65.
We say reasonably sure because calorie counting is imprecise. There’s no way to be 100 percent sure of your calorie intake outside of a lab. So the goal is to have a good enough gauge on how much you can currently eat without gaining. That’s because reverse dieting requires minimal changes in calorie intake over time.
Often as few as 50 to 100 calories a day. For reference, the difference is approximately 0.5 to 1 tablespoon of peanut butter. It’s impossible to hit those numbers exactly. But anyone who counts calories, macros, and/or hand portions will do a much better job than someone who eyeballs it.
Consistency also matters. It’s possible that someone who eats more calories on some days than others could reverse diet. But it’d be pretty tricky to get that slow, steady increase in energy needed to do it properly.
To be clear, reverse dieting is a somewhat advanced method. To do it effectively, you need to be willing to:
Caveats notwithstanding, reverse dieting might be a good approach in three specific situations.
We’ve already covered this one. Gradually increasing calorie intake can help turn up the metabolic heat for people who’ve slashed calories to decrease the scale. But can the technique work for non-dieters?
Say someone just wants to be able to enjoy social situations, needs more nutrients for health and performance, and/or wouldn’t mind welcoming more calorie-dense foods (think: avocado, nut butters, coconut cream, the occasional donut) into their lives?
For those people, reverse dieting probably won’t work as effectively as it would for someone whose metabolism has slowed due to long-term dieting. There are limits to how much metabolism can heat up and cool down. If someone’s already pretty metabolically healthy, there’s (theoretically) less room to shift up.
The takeaway: If someone’s been dieting for a long time and is ready to maintain their current body fat, reverse dieting can help increase maintenance calories, resulting in a more sustainable way of eating long-term.
When someone says they’re eating 1,200 calories and not losing weight, they’re not eating 1,200 calories. They’re usually not estimating their calorie intake effectively.
A highly restrictive diet that keeps calories genuinely low for a few days can increase the chance of accidentally overeating on other days. That’s because our brains evolved to nudge our behavior toward survival, not Instagram glory; the occasional highs average out the steadier lows.
By the end of the week, once you factor in the snacks, weekend drinks, and extra hidden calories, intake may average out to maintenance level. You just don’t notice it because you’re paying attention to the few days you hit those low-calorie numbers.
So, to be clear, in this situation, for reverse dieting to work, you or your client must be subsisting on very few calories and have reached that “bottoming out” point, where you no longer feel like you can reduce your calories.
Provided you’re already mainly eating high-quality, whole foods, reverse dieting could be beneficial. The reasoning here is pretty simple. Slowly increasing calorie intake can help restore metabolic output. That means, to some degree, side-stepping the adaptations that come along with a history of dieting.
But to give your metabolism the time it needs to adapt, you’ll want to stay at a higher calorie intake for roughly as long as you spent dieting. Then, after several months of maintaining, that person can start restricting calories again and see the scale start to move.
The takeaway: If you’re eating a super low-calorie intake and the scale is stuck, reverse dieting might restore metabolism enough to jumpstart fat loss. The more likely outcome is that it allows you to take a break from dieting without gaining weight and brings much-needed pleasure back into your eating life. Then, once you’ve psychologically and metabolically adjusted, you can return to dieting and succeed.
Another everyday use for reverse dieting is to improve body composition. In other words, it means losing fat, gaining muscle, and remaining about the same weight.
Interestingly, Precision Nutrition’s co-founder, John Berardi, Ph.D., developed a similar idea years ago called G-Flux, also known as “energy flux.” He observed that highly active people who consume more calories typically have less fat and more muscle.
For example, professional athletes tend to eat, exercise, and remain very lean. G-Flux is similar to reverse dieting, with one key difference.
When bodybuilders reverse diet, they usually dial down their cardio (although not always), while G-Flux assumes you’ll be doing more than before. The G-Flux version works more effectively for muscle gain than the bodybuilding-style approach.
Here’s why.
You need a solid way to track your food intake. If you’ve been eating in a calorie deficit, you’re likely already using one. Calorie and macro tracking are the most precise methods available outside of a lab, which makes them a logical choice for the small increases reverse dieting requires.
Before you can increase calories, you need to figure out your maintenance intake, which is what you currently can eat to maintain your weight. If you already know this, great.
If not, use our free Nutrition Calculator. It’s the most comprehensive calorie, portion, and macro calculator available and is based on NIH mathematical models for bodyweight planning.
Select “improve health” as your goal and enter the rest of your details. The calculator will suggest calorie, macro, and hand portions close to your maintenance intake. Before adding calories, experiment with your maintenance intake for 2 to 4 weeks, monitoring whether you gain, lose, or maintain.
This will help you personalize the calculator's recommendations. Our nutrition calculator is fantastic, but no calculator can take your dieting history, genetics, and other qualitative factors into account. Only experimentation can do that.
Getting caught up in the ideal macro ratio for your reverse diet can be easy. But the truth is, the most essential macro for reverse dieting is protein. A higher protein diet maximizes muscle protein synthesis and minimizes protein breakdown, which leads to more muscle gain.
This is one reason higher-protein diets are better for improving body composition than moderate or low-protein diets. More protein also helps increase energy because your body uses more energy to process protein than carbohydrates and fat.
Our recommendations for optimal protein intake for building and maintaining muscle range from:
Those aiming to maintain lean mass while losing body fat should shoot for the higher ends of those ranges. As for carbohydrates and fats, the balance between the two isn’t so important. People can lose weight and/or gain muscle with any reasonable mix, as long as it’s sustainable.
So, decide your carbohydrate and fat ratio based on your eating habits and what you can imagine yourself doing in the long term. We could walk you through complicated instructions showing you how to do the calorie math by hand, or you could just use our Nutrition Calculator.
Once the calculator estimates your calorie and macronutrient needs, it automatically converts those numbers into food portions you can gauge with your hands. The result: You can skip weighing and measuring your food and log the details of every meal into calorie and macro tracking apps.
Reverse dieting requires accurate measures of food intake over time, and the small changes necessary to make it work can easily get lost in the noise. Using the calculator makes this process much easier and more reliable, making you more likely to succeed.
Your goal, which you hope to achieve by reverse dieting, determines how many calories you add each time you increase your intake. How often you add calories will depend on the metrics you track. (More on that in Step 5.)
It’s also helpful to consider how motivated you are to eat more food and how much fat you’re willing to gain. You’ll choose one of the three approaches described below depending on your situation and preferences.
Once you’ve picked your plan, it’s time to get started. Track key metrics along the way to determine whether a reverse diet is doing what you want it to do. You might:
Based on the data you continually collect, adjust as needed. Some people may find they can increase their weekly intake without gaining much fat. Others may need to space out increases over longer intervals.
Increasing every two to four weeks is a solid guideline for most people. How do you know when to stop reverse dieting? It depends on your goals. A successful reverse diet can take a few weeks to many months.
Some signs you may want to continue with your reverse diet include:
Signs it may be time to stop your reverse diet include:
Because reverse dieting requires a bit of experimentation to get right, many people find that their final calorie increase leads to more fat gain than they’re comfortable with. By tracking metrics, you can catch that early, adjust your calories one notch, and find your sweet spot (where you can maintain weight while eating a comfortable amount of food).
As the name suggests, reverse dieting is the opposite of traditional dieting. Instead of slowly decreasing your caloric intake to lose weight, reverse dieting allows you to gradually increase your caloric intake to get back to maintenance levels after a period of caloric restriction. Caloric restriction can help you lose weight, but it can also affect your metabolism.
After eating fewer calories, your body adapts to this new normal and functions efficiently on fewer calories. This can make it more challenging to transition back to eating more calories, and reverse dieting can help with this.
If you’ve been eating 1,300 calories a day for weeks to lose weight, your body will not react well to suddenly eating 2,500 calories again. Instead, reverse dieting allows you to increase your caloric intake slowly so your body can adjust to the changes and reduce the risk of unwanted weight gain.
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