It’s pretty safe to assume that most dieters would love to increase their food intake after they lose the weight, and not gain any of it back in the process. Up until now, that has been a stumbling block for many people, because nobody really wants to maintain a restrictive plan forever so they don’t regain the weight they lost.
The whole on-off cycle that we can’t avoid is why restrictive dieting often doesn’t work in the long run – lose weight, feel deprived, go off your diet, rebound eat, gain weight back, feel guilty, go on another diet…you know the drill. Unfortunately, too many people know it.
It goes without saying (but I’ll say it again) that I do not believe that we should be tracking, weighing, or restricting for weight loss. Those things are not aligned with my nutrition philosophy, which is essentially this:
Work out your sh*t around food and your body, make the corresponding changes to what you eat, how you eat, and how you feel about food, and your weight will fall where it needs to fall.
That’s not necessarily where you WANT it to fall, but it’s a fact of life – sometimes, we have unrealistic expectations for how we should look, and that’s society’s fault. Your happy weight is the one where you can eat and move with joy and peace and freedom, not necessarily one that will squeeze you into a size four pants.
That all being said, some fitness people and influencers are promoting something called ‘reverse dieting.’ It sounds interesting, in that they’re promising that after a diet, you can reverse diet (no, it doesn’t mean eating everything in sight) to raise your metabolism and avoid gaining fat, all while adding more food to your diet.
Knowing that metabolism often decreases during restrictive dieting, being able to bring it back up without gaining fat back sounds sort of mythical, doesn’t it?
Let’s look in to reverse dieting, how it works, and whether it’s effective.
What is reverse dieting?
Reverse dieting is basically, increasing caloric intake aka adding food to your diet, after weight loss. The intention of doing this is to eat more while maintaining your weight loss and adding muscle, not fat.
Reverse dieting was first popularized in the bodybuilding community, where bodybuilders prepare for competition by going on super strict eating regimens. These regimens aren’t sustainable, of course, so after competing, people found that if done in a certain way, they could eat more, and maintain a comfortable weight while gaining muscle.
Reverse dieting and metabolism
There is some thought that after the metabolic rate slows with weight loss, it can be increased again by reverse dieting.
Restrictive dieting leads to metabolic adaptation aka a slowed metabolism. Reverse dieting apparently reverses this effect.
Metabolic adaptation, or ‘adaptive thermogenesis,’ happens with weight loss for several reasons:
When you lose weight, your smaller body automatically needs fewer calories to function.
Your body uses fewer calories for digestion.
You also may burn fewer calories because you may be less active and just move less overall.
Reverse dieting depends on adaptive thermogenesis, but in the other direction than restrictive dieting.
One makes your metabolism slow down.
Reverse dieting supposedly speeds your metabolism up – at least, to pre-diet rates. But according to Jennifer Sygo RD, dietitian to the Toronto Raptors and other major sports teams, Reverse Dieting may not be what the media and influencers are making it seem:
Our understanding of this topic is fragmented and emerging. People are formulating their own hypotheses about it.
Increasing your calories after dieting will lead to different outcomes for different people. All things being equal, one person may gain weight in a linear fashion, one person may not gain weight at all.
Dieting and metabolism have always had a complicated relationship. I mean, I can’t write anything about diets and metabolism without bringing up the Biggest Loser, which showed us metabolic adaptation at its very finest:
Lose weight eating a tiny amount of food and exercising until you drop.
Gain weight back once you’re off the show.
Why did this happen?
Probably for a few reasons:
Once they were done with the show, contestants were so hungry, they rebound ate into oblivion.
Their metabolisms took a dive during the intense dieting and workouts that they were doing, because their bodies were doing all they could do to maintain…well, LIFE.
You might be happy if you diet and lose weight, but what does that weight loss cost you?
Sygo compares calorie restricted diets and their effect on the body, to house maintenance:
If your house costs $2500 a month to maintain, and I only give you $1500, what are you going to do?
You’ll have to make some changes: probably lower the thermostat, buy cheaper food, and not as much, you won’t do any upgrades, and you’ll have to get by with whatever you have.
After a month, you won’t notice the difference. But after 6 months? You definitely will.
The longer you’re running on less cash, the longer the house isn’t going to be like it was before. Things will break, it will get run down.
When we chronically diet, we need to dial down a number pf physiological processes to manage the lower calorie intake – the results are often muscle and bone loss, disruption of thyroid hormones, iron deficiency, and digestive changes. People believe that the body is made up of disparate parts, but it’s actually one big system. So when we don’t give it enough energy, it can affect the entire system.
This recent study in Obesity about the Biggest Loser contestants confirms what Sygo says: the body takes drastic measures and reduces metabolism during caloric scarcity.
So, what happens when we start to refeed our bodies, or engage in reverse dieting?
If I then start giving you $2500 to maintain your house, your body is not going to go all the way back to normal right away. You’ll have debt and broken stuff to fix. You might even need MORE than $2500 a month for 6 months to get everything back to where it was.
People who are in the ‘refeeding’ stage of reverse dieting may believe it works, because they don’t necessarily see weight gain for the first little while. That’s because their bodies are likely working behind the scenes to repair the damage done by dieting.
If you’re chronically restricting intake, your body has adapted to eating that few calories, Sygo says. Now, your body will rebuild physiological systems that will have been compromised at that time.
That means that you might not gain weight right away, because your body is using those extra calories to rebuild what was neglected while you were restricting. These are things that don’t necessarily reflect on a scale, such as hormones, brain function, bone loss, etc.
Sygo told me that she has seen people suffer bone loss with just a 300 calorie deficit for five days.
She also said this: there is not a warm blooded human alive who needs 1200 calories to maintain their weight.
Please remember that, the next time you’re staring down a diet.
Reverse dieting sounds like the answer to all of your dieting woes. Lose weight, then eat more, gain muscle, don’t gain all of the weight back.
But it’s often not that simple.
Because a bump in metabolism is one of the claims by people who recommend reverse dieting, I asked Sygo about what happens to the metabolism when a person stops dieting, and starts eating more.
If you have being dieting or restricting, and your metabolic rate has dropped. If you increase your calories/reverse diet, you would expect your metabolism to increase. Having said that, any person who increases body weight will also see their metabolic rate increase – ie the more body you have, the more energy it needs to keep it going.
Honestly, reverse dieting 1000% reminds me of the Metabolic Balance diet, where you basically undereat for a while, then add a few more calories into your repetoire. The people behind this diet say that this way of eating improves your metabolism, which sounds like the claims behind reverse dieting.
In the case of the Biggest Loser, the above trial also found that although metabolic rate declined with weight loss, those who were more successful at keeping the weight off, despite a slower metabolism, were the people who continued to have a high level of physical activity in the years after the show ended.
Some proponents of reverse dieting are very precise about how they add food back into their daily routine. That can mean a lot of counting, tracking, and calculating – three things I don’t recommend for pretty much anyone.
These people recommend adding calories back at a rate of 50 to 100 at a time, every 2-4 weeks. The process is very slow, and they say that in order to see any sort of change, you may have to reverse diet for the same amount of time that you were on a restrictive diet.
To help them nourish themselves properly and repair their bodies from restriction, Sygo adds food back slowly to the plans of her chronic dieters. She told me that they don’t necessarily have to count calories; it might just be an extra spoonful of peanut butter at their snack, or a bit more sweet potato at dinner.
Is reverse dieting effective?
For some people, reverse dieting has no effect. As Sygo told me, we’re all different, and our responses to dieting and subsequent refeeding will vary from person to person. Remember that as with a lot of diet and weight loss plans or programs, we usually hear (or look for) the ‘success’ stories. We don’t tend to gravitate or hear about the times where it all went horribly wrong.
Generally, people will be happy to put their diet plan on social media when they like the results. Not so much, when the plan hasn’t worked for them.
Even if you add foods back into your diet, you may still be under eating and still undernourishing your body. The goal of reverse dieting, of course, is to maintain weight loss and prevent fat gain. If you’ve lost a lot of weight from your initial diet, reverse dieting isn’t necessarily going to put you into a ‘happy zone’ where you’re not struggling to maintain the weight loss.
Also, if you’ve been on a restrictive diet for a prolonged period of time, you’re probably pretty hungry. Our body doesn’t like diets, and we’re all programmed to avoid starvation.
Dieting impacts leptin and ghrelin, our hunger and fullness hormones. When we don’t feed our bodies enough, leptin rises, making us hungry (which is why, when you’re dieting, you might find yourself always thinking about food – leptin creates a situation where we find food irresistable, because it’s trying to prevent you from starving.)
When you end your diet, and move into reverse dieting, bumping up caloric intake by 50 calories a day might not help you avoid rebound eating.
The best advice?
Stop undernourishing yourself. If you want to lose weight, don’t just jump on any diet – work with an RD who can look at your entire food history and guide you through the process.