Current orthodoxy states that coronary heart disease results from the unhealthy lifestyles of westernized adults together with a contribution from genetic inheritance. This does not provide a secure basis for prevention of the disease. Geographical studies gave the first clue that the disease originates during intra-uterine development. Variations in mortality from the disease across England and Wales were shown to correlate closely with past differences in death rates among newborn babies. In the past most deaths among newborns were attributed to low birthweight. This led to the hypothesis that undernutrition in utero permanently changes the body's structure, function and metabolism in ways that lead to coronary heart disease in later life. The association between low birthweight and coronary heart disease has been confirmed in longitudinal studies of men and women around the world. The developmental model of the origins of the disease offers a new way forward.