Research
Hormonal
Diet-induced weight loss causes persistent perturbations in circulating appetite hormones (increased ghrelin, decreased leptin/PYY/GLP-1) that favor weight regain and persist for at least one year.
After losing weight, your body produces more hunger hormones (like ghrelin) and fewer satiety hormones (like leptin and GLP-1). This biological shift makes you hungrier and less full, promoting weight regain. This effect can last for a year or more, explaining why maintaining weight loss is biologically challenging.
GoodSupportsHIGH confidence
With the exception of increases in PP, changes in hormones following weight loss tend to favour weight regain by increasing hunger and promoting energy storage. For example, following diet-induced weight loss, there are increases in levels of ghrelin... and decreases in levels of leptin... PYY... CCK... insulin... and GLP-1.
Why this rating
Supported by multiple studies cited in the review, including a 1-year follow-up study.
Source
Physiological adaptations to weight loss and factors favouring weight regain
Frank L. Greenway · International Journal of Obesity · 2015
DOI 10.1038/ijo.2015.59
narrative_reviewCited 416×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
More from this paper
- Physiological adaptations to weight loss, including hormonal shifts and reduced energy expenditure, actively favor weight regain, making long-term maintenance difficult without medical intervention.Good
- Weight loss leads to a disproportionate decrease in Resting Energy Expenditure (REE) compared to the loss of body mass, creating a metabolic adaptation that favors weight regain.Good
- Gastric bypass surgery alters gut hormone levels (low ghrelin, high GLP-1/PYY) in a way that attenuates appetite, contributing to its efficacy as a treatment for obesity.Good
Related findings · Hormonal
- Initial treatment for type 2 diabetes should be a combination of metformin and either an SGLT-2 inhibitor or a GLP-1 receptor agonist to achieve cardiorenal protection, rather than monotherapy or older agents like sulfonylureas.Strong
- For patients with specific monogenic obesity syndromes (leptin deficiency, POMC/PCSK1/LEPR mutations), targeted pharmacotherapy (recombinant leptin or setmelanotide) is highly effective and should be prioritized, unlike in polygenic obesity.Strong
- Continued weekly administration of 2.4 mg subcutaneous semaglutide prevents weight regain and promotes further weight loss in adults with overweight or obesity, whereas switching to placebo results in significant weight regain.Strong
This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →