Dietary standards for the postponement of coronary heart disease: their practical application in Britain and Ireland.

Abstract

Acomparison is made of the role of fat in the average diets of Britain and Ireland and following implementation of 5 dietary modifications: (i) the consumption of lean meat only; (ii) the substitution of a soft margarine for butter; (iii) the substitution of a soft margarine for shortening; (iv) the substitution of a vegetable oil for lard and (v) the exclusion of cream, ice-cream and sausagemeat from the diet. Fat intake would be reduced by about 18% by modification (i) and by only 5% by modification (v). The implementation of modification (ii) would have the greatest effect on the fatty acid composition of the diet. The total effect of the five modifications would be to reduce the proportion of total energy derived from fat from 42% to 33% in Britain, and from 37% to 28% in Ireland. The P/S ratio of the dietary fat would increase from 0.23 on the normal diet to 0.53 on the modified diet and 0.68 on a diet that had linoleic acid rich ruminant foods substituted for conventional ruminant foods. Dairy produce is the most significant source of saturated fatty acids on both normal and modified diets while cereals and margarine account for most of the intake of polyunsaturated fatty acids. It is concluded that while the proportion of dietary energy derived from fat can be maintained at or below 30%, it would be extremely difficult to partition the energy derived from fat equally among saturated, monounsaturated and polyunsaturated fatty acids or to achieve a P/S ratio of 1.0.