The risk of coronary heart disease is linear according to the cholesterol level. This is important when assessing the justification of the population approach in lowering the cholesterol level among societies. The best way really influencing is to shift the curve to the left parallel with taking care of those who are already hypertension patients. Sociological argument is based on the concept that society is an entity. If you want to change the behaviour of the masses of people, the support of change and eg.
Moral argument comes from the concept, that there is collective responsibility in society.
Medical arguments rise from the fact that medicine alone cannot do very much for the population as the whole. Actually medicine plays minor role in population approach as already experienced in the control of infectious diseases. Because underline causes are behavioural, need of assistance and collaboration with different disciplines are essential. Population strategy means good supply and capacity to make rational healthier personal choices. For instance, the idea that local shopkeepers have the ingredients, which are recommended for the population, is totally beyond medicine.