Summary
A Nature Medicine review describes why people with obesity can differ in insulin sensitivity and related metabolic measures. It also examines how metabolic responses to weight reduction vary.
A review published in Nature Medicine on 27 October 2026 examines why people with obesity can have markedly different metabolic profiles. The authors describe multi-organ insulin resistance as a key driver of obesity-related metabolic complications, while noting that some people with obesity have normal insulin sensitivity and normal results across several metabolic measures.
The article is a review of metabolic differences at cellular, organ-system and whole-body levels. It also considers why the effects of weight reduction on metabolism vary between people. The review’s central point is that excess adiposity and metabolic dysfunction are related, but their relationship is not identical in everyone.
What “metabolically healthy obesity” describes
The review uses “metabolically healthy obesity” for a profile involving normal insulin sensitivity alongside normal fasting blood glucose, oral glucose tolerance, plasma lipid profile and intrahepatic triglyceride content. Oral glucose tolerance reflects how the body responds to a glucose load; intrahepatic triglyceride refers to fat stored in the liver.
Insulin helps regulate the use and storage of nutrients, including glucose and fat. When multiple organ systems become less responsive to insulin, metabolic regulation can be disrupted. The review identifies this multi-organ insulin resistance as a key pathogenic driver of complications including atherogenic dyslipidemia, metabolic dysfunction-associated steatotic liver disease and type 2 diabetes.
Why metabolic variation matters
The distinction helps describe why people with similar obesity may not share the same metabolic measurements. The authors discuss differences across levels of biology, from cells and organs to the whole body, as well as variation in therapeutic effects after weight reduction. Understanding these differences may help identify factors linking excess adiposity to metabolic dysfunction and disease.
The article is a review rather than a report of a new clinical trial. Its abstract sets out the questions and framework it covers, but does not provide detailed estimates of how common each metabolic profile is or specific results for individual weight-reduction approaches.