June/July 2021 Issue

Ask the Expert: Reverse Dieting
By Toby Amidor, MS, RD, CDN, FAND
Today’s Dietitian
Vol. 23, No. 6, P. 10

Does it really prevent weight regain?

Q: Some of my clients have been asking about “reverse dieting” to limit weight regain after weight loss. What is reverse dieting, what does it entail, and does science back up this approach?

A: Many dieters immediately return to former eating habits after weight loss, which can undermine weight maintenance efforts and promote weight regain. Reverse dieting, commonly known as “the diet after the diet,” is meant to limit weight regain by slowly adding calories to the diet after meeting one’s desired weight and is meant to prevent the common occurrence of regain. There’s no research yet that supports this approach for weight maintenance, but a couple of studies on its efficacy are in progress.

What’s Behind the Approach?
As an example of reverse dieting, someone on a 1,200-kcal diet for weight loss would increase intake by 50 kcal every few weeks until reaching a calorie level that maintains weight. It’s meant to be undertaken over several weeks to several months—about as long as one’s weight loss took, according to some advocates.1 Reverse dieting was developed and popularized by husband-wife fitness team Layne Norton, PhD, and Holly Baxter, MS, who authored and self-published the book The Complete Reverse Dieting Guide in 2020.

According to a meta-analysis of 29 long-term weight loss studies, more than one-half of weight lost among subjects was regained within two years, and more than 80% of weight was regained by five years.2 This is due in part to the theory of adaptive thermogenesis, which states that calorie restriction and weight loss, and attempting to sustain that weight loss, cause changes in behavior and the body’s metabolic, neuroendocrine, and autonomic systems that “oppose” weight maintenance by decreasing resting energy expenditure.3 Essentially, the body reacts to weight loss by trying to preserve the mass that remains and return the body to its previous weight.

In line with the theory of adaptive thermogenesis, reverse dieting proponents claim that the slow increase in calories—rather than a quick return to a relatively high-calorie diet—can limit the decrease in resting energy expenditure rate that occurs with weight loss, ultimately enabling dieters to consume higher calorie levels without regain. First employed primarily by professional bodybuilders and other athletes to maintain muscle mass while keeping fat mass low, it has since crossed over into the mainstream.4

The Research
There’s a lack of data concerning the practice of reverse dieting, but two studies are underway. The first study, funded by George Mason University, a public research university in Fairfax, Virginia, is testing reverse dieting for the prevention of metabolic adaptation following a period of calorie restriction in weight-training athletes.5 The second study, sponsored by the University of Colorado, is following 24 participants with overweight or obesity who have lost more than 10% of their body mass, randomizing subjects to a reverse dieting or standard care control intervention for 12 weeks.6 Results aren’t yet available from either of these studies.

Recommendations for Practitioners
While reverse dieting is used with anecdotal success among body builders and other athletes, there isn’t enough evidence to support recommending it. Furthermore, it may be impractical for many clients. For example, an extra, 30 or 50 kcal per day can be tedious to record, especially for clients who weren’t counting calories as part of their weight loss plan. Also, this number of extra calories doesn’t equate to much food—for instance, only five or six almonds, seven or eight peanuts, or half a stick of string cheese.

For clients who have lost weight and want to keep it off, regular follow-up visits with an RD can help with weight management. RDs can let clients know about the National Weight Control Registry, which was established in 1994 and is the largest prospective investigation of long-term successful weight loss maintenance. Clients who are interested can join the study at nwcr.ws. Moreover, dietitians can refer to the article “Lifestyle Changes That Keep Pounds Off” in the August/September 2020 issue of Today’s Dietitian and share the information with clients.

— Toby Amidor, MS, RD, CDN, FAND, is the founder of Toby Amidor Nutrition (tobyamidornutrition.com) and a Wall Street Journal bestselling author. She’s written several cookbooks, including The Best 3-Ingredient Cookbook and The Best Rotisserie Chicken Cookbook. She’s also a nutrition expert for FoodNetwork.com and a contributor to U.S. News Eat + Run and other national outlets.

1. Link R. What is reverse dieting? Healthline website. https://www.healthline.com/nutrition/reverse-dieting. Published April 30, 2019.

2. Anderson JW, Konz EC, Frederich RC, Wood CL. Long-term weight-loss maintenance: a meta-analysis of US studies. Am J Clin Nutr. 2001;74(5):579-584.

3. Rosenbaum M, Leibel RL. Adaptive thermogenesis in humans. Int J Obes (Lond). 2010;34:S47-S55.

4. Trexler ET, Smith-Ryan AE, Norton LE. Metabolic adaptation to weight loss: implications for the athlete. J Int Soc Sports Nutr. 2014;11:7.

5. Can reverse dieting prevent weight regain after weight loss. ClinicalTrials.gov website. https://clinicaltrials.gov/ct2/show/study/NCT03434431. Updated March 1, 2019.

6. Feasibility and preliminary efficacy of a reverse diet as a novel weight loss maintenance strategy for weight-reduced adults with overweight/obesity. ClinicalTrials.gov website. https://clinicaltrials.gov/ct2/show/NCT03560635. Updated February 10, 2021.