['The association between low birth weight and adult disease is well known. Less is known on long-term effects of high birth weight.', 'This study aims to investigate whether a high birth weight increases risk for adult metabolic disease.', 'Swedish term single births, 1973-1982 (n\u2009=\u2009759,999), were studied to age 27.5-37.5 years using Swedish national registers. Hazard ratios (HRs) were calculated in relation to birth weight for type 2 diabetes, obesity, hypertension and dyslipidaemia.', 'Men with birth weights between 2 and 3 standard deviation score (SDS) had a 1.9-fold increased risk (HR 1.91, 95% confidence interval [CI] 1.25-2.90) of type 2 diabetes, whereas those with birth weights above 3 SDS had a 5.4-fold increased risk (HR 5.44, 95% CI 2.70-10.96) compared to men with birth weights between -2 and 2 SDS. The corresponding HRs for women were 0.60 (95% CI 0.40-0.91) and 1.71 (95% CI 0.85-3.43) for birth weights 2-3 SDS and >3 SDS, respectively. Men with birth weights between 2 and 3 SDS had a 1.5-fold increased risk (HR 1.47, 95% CI 1.22-1.77) of obesity. The corresponding risk for women was 1.3-fold increased (HR 1.32, 95% CI 1.19-1.46). For men and women with birth weights above 3 SDS, the risks of adult obesity were higher, HR 2.46 (95% CI 1.63-3.71) and HR 1.85 (95% CI 1.44-2.37), respectively.'] Is a high birth weight associated with increased risk of type 2 diabetes and obesity?