Research
Hormonal
Adiposity signals (leptin and insulin) decline disproportionately to fat mass loss because smaller adipocytes secrete less leptin and are more insulin-sensitive, creating a persistent 'energy depletion' signal even when fat mass is stable.
Your body's 'fuel gauge' (leptin/insulin) reads lower than your actual fat mass suggests because your fat cells have shrunk. This tricks your brain into thinking you are starving, driving hunger and conserving energy. This is a normal physiological response to weight loss.
StrongSupportsHIGH confidence
The integrated adipose signal conveyed to the brain and peripheral tissues is, therefore, that energy reserves are low and the fuel tank is far from full.
Why this rating
Supported by multiple human and animal studies cited in the review.
Source
Biology's response to dieting: the impetus for weight regain
Paul S. MacLean et al. · American Journal of Physiology-Regulatory, Integrative and Comparative Physiology · 2011
DOI 10.1152/ajpregu.00755.2010
narrative_reviewCited 446×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
More from this paper
- Biological adaptations to energy-restricted weight loss—including reduced leptin/insulin, increased hypothalamic NPY/AgRP, and suppressed energy expenditure—create a persistent drive for weight regain that actively counteracts behavioral efforts to maintain weight loss.Strong
- Energy expenditure declines after weight loss due to both reduced body mass (less tissue to maintain and move) and enhanced metabolic efficiency (regulated by homeostatic feedback loops), creating a persistent energy gap.Strong
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 →