Research
Hormonal
Obesity results from a loss of homeostatic energy balance regulation driven by evolutionary mismatch and peripheral signals (leptin/insulin) failing to inhibit orexigenic pathways (NPY/AgRP) due to resistance mechanisms.
Your body has a biological defense against weight loss involving hormones like leptin and neuropeptides like NPY. In obesity, these signals often fail (resistance), making it harder to lose weight through willpower alone. Understanding this helps shift the focus from 'eating less' to addressing the underlying hormonal signaling and environmental factors.
StrongSupportsHIGH confidence
This energy homeostasis, in most cases, regulates body weight tightly. However, it has been argued that evolutionary pressure has resulted in a drive to eat without limit when food is readily available. The disparity between the environment in which these systems evolved and the current availability of food may contribute to over-eating and the increasing prevalence of obesity.
Why this rating
This is a comprehensive review of established physiological mechanisms and genetic evidence in humans and animal models.
Source
Appetite control
Katie Wynne et al. · Journal of Endocrinology · 2005
DOI 10.1677/joe.1.05866
narrative_reviewCited 428×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
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