Dietary studies on two rural Italian population groups of the Seven Countries Study. 2. Concurrent validation of protein, fat and carbohydrate intake.

On 18 subjects from two rural areas in Italy which were part of the Seven Countries Study (Crevalcore and Montegiorgio), we carried out the concurrent validation of protein, fat, fatty acid and carbohydrate intake in the diet at the thirty-first year follow-up in 1991. The values of the above nutrients obtained using food composition tables from the weighted record method for dietary surveys were compared with the values from chemical analysis of food composites. In both areas for protein, fat and carbohydrate intake the inter-individual variation was large. For protein intake the mean difference was statistically significant but not for fat intake. From 1960 to 1991 protein and fat intake tended to decrease and for protein the means of differences between analysis and calculation were, in general, statistically different. For dietary saturated and polyunsaturated fatty acids, the means of differences were statistically significant in Crevalcore, but this was not the case in Montegiorgio for polyunsaturated fatty acids. The intake of trans fatty acids in both areas was rather low. Available and unavailable carbohydrate intake of both areas showed no statistically significant difference. The mean differences between analysis and calculation for both areas were statistically significant with the exception of cellulose in Crevalcore and sugars in Montegiorgio.