If you've ever lost weight, you can probably relate to the fact that losing it is easier than keeping it off: About 80% of dieters go on to regain all of the weight they lost, and some end up heavier than before trying to lose weight, according to the Endocrine Society.
This common problem is that driving force behind the social media trend known as reverse dieting. The approach to eating was first popularized by bodybuilders, who will often lose weight before a competition and then gradually return to their normal size.
The theory is that after you lose weight, you can train your metabolism to eat more food and not gain weight because you're adding calories back to your diet very gradually. Sounds great, right?
Certainly, the promise of eating more and still maintaining weight loss is alluring, but there are some drawbacks. Here's what you need to know about reverse dieting, the science behind it, and what experts say about it.
Reverse dieting usually involves adding back 50 to 100 calories per day -- mostly in the form of protein -- in weekly steps, Lilian de Jonge, Ph.D., professor at the department of nutrition and food studies at George Mason University, tells TODAY.com. That amount is roughly the number of calories in one-quarter of a cup of cottage cheese or a large hardboiled egg, so it's not a huge increase in food.
So, once you've lost the amount of weight you want to lose, you'll begin adding 50 to 100 calories per day while tracking to see if you regain weight. After a week, you'll repeat the process, adding another 50 to 100 calories per day.
If your weight is staying steady, you can keep gradually adding back calories to your diet until you notice you're gaining weight. At this point, you'll shave some calories off your daily intake until your weight steadies. The idea is that taking this step-by-step approach can help you gradually loosen restrictions to your diet and find the calorie level where you can comfortably maintain your weight.
Reverse dieting is safe as long as you're balancing your diet and adding back nutritious whole foods, and it's possible it can be helpful. However, keep in mind that there's no scientific evidence that reverse dieting has any effect on your metabolism, and the practice has some drawbacks.
Since reverse dieting is intended to counter the ways your metabolism responds to strict dieting and weight loss (also known as metabolic adaptations), it helps to understand some metabolism basics.
As you lose weight, your metabolism adjusts to a smaller body. Suppose you used to weigh 200 pounds and you now weigh 175 pounds. It makes sense that you'd need fewer calories to maintain your lower body weight. But your body takes things a step further.
Evidence suggests that your body employs several adaptations after dieting.
When you cut calories, your body senses you're giving it less fuel, so your metabolism slows down to save energy. De Jong explains that this is an evolutionary response left over from when food was not abundantly available all year round. However, these days, food is readily available 24/7, so this creates a disadvantage.
Whether you're exercising to lose weight or to keep fit, rigorous exercise may result in you unknowingly trying to save energy during your non-workout hours -- an adaptation known as constrained energy expenditure. This means that even if you're burning 400 calories in a spin class, your overall calorie burn that day may be similar to days where you don't work out because you may still be taking things easy outside of your workout, such as by spending more time sitting or opting for the escalator instead of the stairs.
These conditions make it tough (but not impossible) for many people to keep weight off, which is why the idea of reverse dieting is so appealing.
Reverse dieting is billed as a way to restore your metabolism, but there's no evidence that it does, Dr. Robert Kushner, medical director of the Center for Lifestyle Medicine at Northwestern Medicine in Chicago, tells TODAY.com.
Gradually reintroducing food after weight loss is a practical and standard approach used in both research studies and clinical practice, but the reason has to do with keeping an eye on the scale to make sure you're maintaining and not gaining weight. In other words, it doesn't trick your metabolism or reset your metabolism; it's just a common approach to weight maintenance.
That said, reverse dieting may offer a potential benefit to your cardiometabolic health, as it may help you avoid yo-yo dieting, the pattern of losing and regaining weight, which research shows is associated with poorer cardiovascular health among women.
While there's no formal scientific proof that reverse dieting will prevent weight regain after weight loss, it's a sensible approach that may be helpful.
Kushner says that "after a period of dieting, slowly reintroducing more food makes sense because it helps you increase the variety of foods you eat and feel more in control while also assessing any weight changes."
In other words, reverse dieting encourages you to assess whether you're keeping your weight stable or gaining weight. If you notice weight gain, you can adjust your diet to prevent additional weight gain.
Instead of reverting back to your former way of eating, reverse dieting encourages you to continue with the eating pattern that helped you lose weight while also allowing for a less restrictive diet.
Studies suggest that dieting to lose weight is associated with an increase in stress that takes a toll on your emotional and physical well-being. Therefore, by enjoying a less restrictive diet, reverse dieting might reduce the negative emotional impact of dieting.
There's also the possibility that reverse dieting will help normalize your appetite-regulating hormones. It's easier to manage your weight if you're not excessively hungry all the time.
If you turned to unsustainable eating habits while losing weight, reverse dieting can help you discover a more realistic and enjoyable eating pattern while helping you to maintain a lower weight.
Research suggests that tracking behaviors like counting calories and regularly weighing yourself, necessary practices with reverse dieting, may be associated with disordered eating. So, take note of the emotional impact of these behaviors: If tracking your calorie intake makes you anxious, this is not the right approach for you.
Scale fluctuations are completely normal due to factors like a heavy meal and water retention, but if these small shifts impact your emotional wellbeing, that's anothe reason to reconsider this approach.
If you already have a history of disordered eating, reverse dieting (and intentional weight loss in general) is not advised.
In order to prevent weight regain, it's helpful to continue the behaviors that helped you lose weight, but that's easier to do when you establish and practice healthy weight loss tactics.
If your diet is too restrictive, gradually increasing your calorie intake can be a helpful (albeit tedious) strategy -- but not necessarily because it's hacking your metabolism, as many reverse dieting proponents believe. It's more likely that it's helping you identify the balance between an eating and exercise pattern that you can maintain.
Finally, remember that weight loss is not just a matter of calories in-calories out, as reverse dieting might suggest. Your body is complex, and there's more to it than that. Also, it's not necessary or beneficial to pursue thinness; healthy bodies come in a range of shapes and sizes.