ABSTRACT
Each of the following three paradigms can be used as a way of considering the epidemiological in¡uences on an individual during the life course.
Programming This epidemiological paradigm considers the long-term effects of environmental exposures during critical periods of growth, including in utero development and early life. Programming is also known as the ‘critical period model’ because it assumes that there are specic periods during which certain exposures will have lasting effects on the structure or function of body organs. The classic example of this is the Barker hypothesis, which states that an effect of in utero malnutrition is an increased risk of coronary heart disease (CHD) in adulthood. This hypothesis has since been extended to a wide range of chronic diseases, such as type 2 diabetes and hypertension.
