People who were small at birth seem vulnerable to later disease through three kinds of process. First, they have led functional capacity in key organs such as the kidney. A second process linking low birth weight to later disease is the setting of hormones and metabolism. An undernourished baby may establish a ‘thirfty’ way of handling food. A third link between low birth weight and later disease are that people who were small at birth are more vulnerable to an adverse environment in later life. Phillips, Walker et al (2000) found people who were small at birth are known to have heightened response to stress and also increases vulnerability to the effects of lack of exercise in later life and prone to develop glucose intolerance (Eriksson, Yliharsila et al. 2004)