S Kinlay1, R F Heller, J A Halliday. 1. Centre for Clinical Epidemiology and Biostatistics, University of Newcastle, New South Wales Australia.
Abstract
BACKGROUND: A short 12-term questionnaire was designed to measure changes in the dietary intake of saturated and total fat among groups of people attending health promotion events. A simple score (the fat-habits score) derived from the questionnaire was compared with estimates of saturated and total fat intake (% total energy) estimated from a standard 180-item food frequency questionnaire of 105 children (less than 18 years) and 202 adults (greater than 18 years). RESULTS: The correlation coefficients for saturated fat intake and the fat-habits score were 0.60 (95% CI = 0.50 to 0.68) in adults and 0.54 (95% CI = 0.39 to 0.66) in children, and those for total fat and the fat-habits score were 0.46 (95% CI = 0.41 to 0.56) in adults and 0.40 (95% CI = 0.22 to 0.55) in children. Linear regression equations relating the fat-habits score to saturated and total fat were used to predict changes in fat intake in 12 children and 27 adults who completed both questionnaires 6 months apart. The differences between the predicted changes in saturated and total fat and the observed changes measured by the food frequency questionnaires were not significant (saturated fat: adults -0.3%, 95% CI = -1.3 to 0.7%; children -0.2%, 95% CI = -1.7 to 1.3%; total fat: adults -0.6%, 95% CI = -2.9 to 1.7%; children -0.4%, 95% CI = -2.8 to 2.0%). The study had a 90% power of detecting a difference between the predicted and the observed changes for saturated fat of greater than +/- 1.7% (adults) and +/- 2.5% (children), and for total fat of greater than +/- 3.9% (adults) and +/- 4.0% (children). Conclusion. Thus simple scores can be used to evaluate group changes in fat intake.
BACKGROUND: A short 12-term questionnaire was designed to measure changes in the dietary intake of saturated and total fat among groups of people attending health promotion events. A simple score (the fat-habits score) derived from the questionnaire was compared with estimates of saturated and total fat intake (% total energy) estimated from a standard 180-item food frequency questionnaire of 105 children (less than 18 years) and 202 adults (greater than 18 years). RESULTS: The correlation coefficients for saturatedfat intake and the fat-habits score were 0.60 (95% CI = 0.50 to 0.68) in adults and 0.54 (95% CI = 0.39 to 0.66) in children, and those for total fat and the fat-habits score were 0.46 (95% CI = 0.41 to 0.56) in adults and 0.40 (95% CI = 0.22 to 0.55) in children. Linear regression equations relating the fat-habits score to saturated and total fat were used to predict changes in fat intake in 12 children and 27 adults who completed both questionnaires 6 months apart. The differences between the predicted changes in saturated and total fat and the observed changes measured by the food frequency questionnaires were not significant (saturatedfat: adults -0.3%, 95% CI = -1.3 to 0.7%; children -0.2%, 95% CI = -1.7 to 1.3%; total fat: adults -0.6%, 95% CI = -2.9 to 1.7%; children -0.4%, 95% CI = -2.8 to 2.0%). The study had a 90% power of detecting a difference between the predicted and the observed changes for saturatedfat of greater than +/- 1.7% (adults) and +/- 2.5% (children), and for total fat of greater than +/- 3.9% (adults) and +/- 4.0% (children). Conclusion. Thus simple scores can be used to evaluate group changes in fat intake.