A simple method of assessing the effect of dietary advice to reduce plasma cholesterol

A simple eight-item questionnaire was used to assess the saturated fat content of the diet of participants in a multifactorial trial of the prevention of coronary heart disease. The questionnaire was found to have good repeatability, and a score derived from it correlated significantly with a more lengthy dietary recall method (the 3-day diary) in assessing the amount of saturated fat in the diet: high scores reflected a low saturated fat intake. The score was higher among those advised to reduce their saturated fat intake (suggesting that they had taken the advice) than among those who had been given no advice. Men given personal counseling had higher scores than those who were only sent letters and leaflets containing essentially the same information by post. Among unadvised control men there was no correlation between the score and the plasma cholesterol level; but among the men given advice, the higher their score the greater was the fall in their plasma cholesterol. This highlights the paradox that an individual's current saturated fat intake cannot predict his plasma cholesterol level, yet a change in this level is readily predicted by even a crude assessment of change in dietary fat.