They also found that child size rather than birthweight predicted childhood insulin and glucose metabolism.[22] This cohort was followed again at age 18, where children born small continued to be smaller and lighter.[23] As these authors argue, it will be important for future research to track health outcomes consistently from early childhood through to later adulthood to determine whether the effects of perinatal risk change over the life course, and how childhood underweight translates to adult health (such as overweight and obesity) in later life. The gene discussed is INS; the disease is obesity due to melanocortin 4 receptor deficiency.