Type 2 diabetes is a chronic metabolic disease characterized by high blood glucose caused by a combination of insulin resistance and impaired insulin secretion. It typically develops gradually, often in adults, and is strongly linked to obesity, physical inactivity, aging, and genetic susceptibility. Central obesity and excess visceral fat promote low grade inflammation and the release of free fatty acids and adipokines that interfere with insulin signaling in muscle and liver. As insulin resistance worsens, pancreatic beta cells initially increase insulin output but eventually become dysfunctional, leading to persistent hyperglycemia.

Research highlights that diet quality and energy balance are central to both risk and management. High intake of refined carbohydrates, sugary drinks, and energy dense processed foods increases risk, while dietary patterns rich in whole grains, vegetables, fruits, legumes, nuts, and unsaturated fats improve insulin sensitivity and support weight control. Regular physical activity enhances glucose uptake by muscles independently of insulin, reduces visceral fat, and improves cardiovascular health.

Genetic studies have identified many variants that modestly affect risk, mostly by influencing beta cell function, but lifestyle strongly modifies genetic vulnerability. Emerging work emphasizes the role of sleep, stress, and the gut microbiome, suggesting that circadian disruption, chronic stress hormones, and altered microbial communities may contribute to insulin resistance.

Complications of poorly controlled type 2 diabetes include cardiovascular disease, kidney failure, neuropathy, retinopathy, and increased infection risk. Early detection through screening of high risk individuals and aggressive management of blood glucose, blood pressure, and lipids can markedly reduce these outcomes. Long term studies show that weight loss, improved diet, and sustained physical activity can prevent or delay type 2 diabetes in high risk people and can sometimes induce remission in those already diagnosed.