Assessment of advice to reduce dietary fat and non-milk extrinsic sugar in a free-living male population

To compare the effect of advice to reduce both dietary fat and sugar with advice to reduce fat alone on subsequent dietary intake in Scottish men. A parallel design intervention study was employed to measure compliance to the two types of dietary advice. Subjects were randomly assigned to Group 1 (advice to reduce fat and non-milk extrinsic (NME) sugar), Group 2 (advice to reduce fat only, ad libitum sugar) or a control Group 0 (no advice). Compliance was assessed by two 4-day food diaries over 6 months. The study was conducted in the Strathclyde area of Scotland. Subjects were normal to moderately overweight Scottish men. The men recruited were non-dieting and volunteered for a 'healthy eating' study with the aim to improve the 'healthiness' of their diet. Groups 1 and 2 achieved the dietary target for fat, reducing their mean intake to below 35% energy. Group 1 achieved a statistically significant reduction in percentage energy from NME sugar in the short term (6 weeks), decreasing their mean intake from 9.9% to 7.2% energy. This initial decrease appeared to slip back towards baseline levels at 6 months (8.1% energy from NME sugar) and was no longer significantly different from baseline. At 6 months Group 1 reported a significantly lower mean energy intake than at baseline, whereas Group 2 adjusted for an initial decrease in energy intake and by 6 months energy intakes were not significantly different from baseline intakes. Group 2 appeared to compensate for the absolute reduction in dietary fat with a slight increase in total sugars and the maintenance of NME sugar intakes. Subjects in Group 1 complied with advice to reduce both fat and sugar over 6 weeks but to a lesser extent over 6 months. The 1.8% reduction in percentage energy from NME sugars in Group 1 at 6 months may not have reached significance due to the small sample size. Alternatively it may be that free-living populations find it hard to maintain concurrent reductions in fat and sugar owing to the well-documented inverse relationship between intakes of these macronutrients when expressed as a proportion of energy.