Reverse dieting is not a term that comes up often in standard post-bariatric nutrition conversations, but it is something that becomes increasingly relevant in the maintenance phase, particularly for people who have been eating at very low calorie levels for an extended period and are seeing the effects of metabolic adaptation.
Here is what it involves, why it matters, and how we have thought about it two years on.
What is reverse dieting?
Reverse dieting is the practice of very gradually increasing calorie intake after a period of significant restriction, with the aim of raising the metabolic rate without triggering fat regain. The idea is that the body has adapted to a low calorie intake by lowering its metabolic rate, and that a controlled, slow increase in calories gives the metabolism time to upregulate before the surplus becomes large enough to cause meaningful fat gain.
It is used by bodybuilders and athletes coming out of a competition diet, and increasingly discussed in the context of bariatric surgery maintenance, where prolonged low-calorie eating during the weight loss phase can leave the metabolism significantly suppressed.
Why it is relevant after gastric sleeve
After gastric sleeve surgery, the combination of dramatic calorie restriction and rapid weight loss creates the conditions for significant metabolic adaptation. By the time most people reach their goal weight or the weight loss phase slows substantially, their resting metabolic rate may be considerably lower than would be expected for their body size. This is the metabolic reality that makes weight regain so common after major weight loss if the approach to maintenance is simply to stop restricting and eat normally.
A reverse dieting approach attempts to address this by raising calories in small increments over weeks and months, monitoring the body’s response at each step, and only continuing to increase if the previous increase has been well tolerated in terms of weight stability. The goal is to land at a maintenance calorie level that is as high as possible while keeping weight stable.
How this works in practice after gastric sleeve
After gastric sleeve surgery, the stomach capacity limits are a significant constraint on this process. In the early years, adding 50 to 100 calories per week is a very small increment, and the mechanical restriction of the sleeve means that dramatically increasing calorie intake requires either eating more frequently, choosing more calorie-dense foods, or both. The latter is risky because calorie-dense foods after gastric sleeve often mean high-fat, high-sugar options that are not nutritionally optimal.
A more practical framing for the post-bariatric context is the gradual expansion of food variety and modest increase in portion complexity as weight stabilises, rather than a strict numerical calorie reverse diet. Ensuring that the diet provides enough protein, enough micronutrients, enough fibre, and enough total energy to support an active lifestyle without ongoing severe restriction is the goal.
What we have noticed
In year two, as weight loss has slowed and maintenance has become the focus, both of us have naturally eaten somewhat more than in year one without meaningful weight change. The body has adapted upward to some degree. Whether this reflects a true metabolic upregulation or simply the natural settling that happens as the stomach accommodates slightly more volume is difficult to disentangle.
What is clear is that the approach that worked well for rapid weight loss in year one, very high protein, very low carbohydrate, very low overall calorie intake, is not the right long-term maintenance approach. A sustainable maintenance diet needs to include enough food to support health, energy, and activity without either continuing aggressive restriction or triggering significant regain.
Sources
Rosenbaum and Leibel: Adaptive thermogenesis in humans. Trexler et al: Metabolic adaptation to weight loss: implications for the athlete. British Obesity and Metabolic Surgery Society (BOMSS): Long-term follow-up after bariatric surgery.
About this content
This blog is written by James and Kirsten, a couple from the UK who had gastric sleeve surgery together in March 2024.
We started this blog because we couldn't find any sources of content that details before surgery, the surgery and then life post surgery - so we decided to write one ourselves.
Everything on this site is based on our own experience and the research we have done along the way. It is not medical advice. Gastric sleeve surgery is a serious procedure and every patient's journey is different. Please always consult your own bariatric team or GP before making any decisions about your health or treatment.
Some posts on this site may contain featured or sponsored content, or affiliate links. Where this is the case, it will always be clearly stated at the top of the article. Our opinions are always our own.
Publish Date: 5 May 2026 | Last Reviewed: 7 June 2026 | Next Planned Review: 7 December 2027