Contribution of food items to the day-to-day-fluctuation of energy intake in normal weight subjects.

BACKGROUND In normal weight subjects daily energy intake is not constant and fluctuates by 1.500 kcal within 14 days. The present paper analyses the contribution of the various food groups to these short-term fluctuations of energy intake. METHODS 1.400 dietary records of 100 normal weight subjects were evaluated that were recorded during a 14 day period. RESULTS Small day-to-day changes of energy intake are the result of an additive effect of per se insignificant changes of various food groups. Food groups which contribute substantially to the observed fluctuations of daily energy intake are cake, bread, cheese, sausages, chocolate and nuts and fast food, added by smaller significant changes of butter, processed meat and oil. The increase of energy intake is due to both an augmented food quantity and the frequency of consumption. Changes of food quantity of individual food groups are in the range of 6-170 g during the 14 day period. In relation to the total change of 550 g most food groups change so little that it will not be recognized to affect hunger / satiety regulation. CONCLUSION These data give insight into the eating habits of a group of normal weight subjects which corresponds to the previously reported data of a group of obese subjects. Larger alterations are mainly due to the increased consumption of food items with high energy density with a special emphasis on the intake of cake. Considering that 70 % of the observed changes are due to fluctuations of rather small quantities of only 6 food groups with high energy density a progressive shift of average daily energy intake will not be noticed thus easily favoring the development of overweight and obesity.