Evaluation of a food frequency questionnaire with weighed records, fatty acids, and alpha-tocopherol in adipose tissue and serum

The authors examined the validity of a self-administered 180-item food freq uency questionnaire in 125 Norwegian men aged 20-55 years who filled in the questionnaire and completed 14-day weighed records in fall 1995 to winter 1995/6. Spearman correlation coefficients between the two measurements rang ed from 0.42 for percent of energy from fat to 0.66 for sugar intake (media n r = 0.51). On average, 39% of the men were classified in the same quartil e with the two methods, and 3% in the opposite quartile. Correlation coeffi cients between intake of fatty acids estimated from the questionnaire and t he relative amounts of fatty acids in adipose tissue were: linoleic acid (1 8:2, n-6), r = 0.38; alpha-linolenic acid (18:3, n-3), r = 0.42; eicosapent aenoic acid (20:5, n-3), r = 0.52; and docosahexaenoic acid (22:6, n-3), r = 0.49. The correlations for these fatty acids between the total serum lipi ds and the diet were 0.16, 0.28, 0.51 and 0.52, respectively. The data sugg est that very-long-chain n-3 fatty acids in adipose tissue and total serum lipids reflect the dietary intake of very-long-chain n-3 fatty acids to the same degree. No associations were observed between intake of alpha-tocophe rol and concentration in adipose tissue and serum.