The Metabolic Revolution in Dermatology: Obesity, Insulin Resistance, and Ultra-Processed Diets as Drivers of Skin Inflammation

Inflammatory dermatoses are increasingly linked to systemic metabolic factors. Obesity and insulin resistance create a pro-inflammatory milieu that affects the skin. Adipose tissue functions as an endocrine organ secreting adipokines and cytokines that drive chronic inflammation with notable skewing toward T-helper 1 (Th1)/Th17 signaling. Hyperinsulinemia, elevated insulin-like growth factor-1 promote keratinocyte proliferation, sebum production, and autoinflammation, contributing to a multitude of skin diseases including hidradenitis suppurativa, acne, psoriasis, atopic dermatitis (AD), acanthosis nigricans, hirsutism, scarring alopecias, intertrigo, and chronic idiopathic urticaria. Concomitantly, ultra-processed diets low in fiber and high in additives detrimentally affect the gut-skin axis. Diets rich in emulsifiers, sugars, and fructose alter the gut microbiome and increase intestinal permeability, leading to metabolic endotoxemia and increased systemic inflammation. High-fructose corn syrup in sweetened beverages is metabolized via hepatic fructokinase, promoting de novo lipogenesis and excess uric acid, a cascade implicated in metabolic fatty liver disease and heightened inflammation. These dietary factors have been correlated with aggravated skin diseases, where fast-food intake (≥3× weekly) is associated with increased risk of severe AD in children. Emerging evidence suggests that dietary modifications may help mitigate skin inflammation in select patients. At the same time, the advent of glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonists may improve metabolic parameters and could represent promising adjunctive therapies in select inflammatory dermatoses. Dermatologists can serve as sentinels, identifying cutaneous signs of insulin resistance (eg, acanthosis nigricans, acrochordons, and other skin diseases driven by insulin resistance) and addressing lifestyle factors as part of routine care.