Epidemiological studies have identified an association between size at birth and adult risk for type 2 diabetes mellitus and cardiovascular disease. In contemporary populations, children who are relatively small at birth and show rapid infancy weight gain are at greatest risk for the development of childhood obesity, increased visceral fat and insulin resistance: possible early markers of adult disease risk. Individuals presenting to growth clinics with short stature and a history of low birthweight will not have shown post-natal catch-up growth and may be a very heterogeneous group. Nevertheless, there are some data to suggest that as a group they are insulin resistant with decreased lean mass. Growth hormone treatment leads to reversible worsening of the insulin resistance, and short-term data do not indicate an increased risk for type 2 diabetes. However, further long-term follow-up is required, and particular care should be taken in monitoring children with a strong family history of type 2 diabetes and those from ethnic groups in which there is a high background prevalence of the disease.