Evidence of nutrient dilution with high sugar intakes in older South Africans
Aims: To investigate the association between added sugar intake and (i) micronutrient intake, (ii) energy profiles and (iii) body mass index (BMI) of a sample of older South Africans. Methods: A sample of 200 free-living South Africans of mixed ancestry, aged 65 years and older and resident in Cape Town, was randomly drawn using a two-stage cluster design. Dietary intake was assessed using an interviewer-administered quantified food frequency questionnaire. Statistical analyses: Spearman correlation coefficients were used to investigate the associations between (i) sugar intake and (ii) total energy intake, and macro- and micronutrient intakes and BMI. Differences between the subgroups according to either tertiles of sugar or total energy intake were tested for significance at the P=0.05 level using analysis of variance (ANOVA ). Age was controlled for in the ANOVA models, according to two groups: 65–74 years and >75 years. Results: For both men and women, the proportion of energy provided by sugars did not differ across the tertiles of energy intake, suggesting that subjects with the highest energy intakes consumed greater quantities of all foods, rather than selecting foods high in sugar. An inverse association was found between the proportion of total energy provided by sugar and (i) the proportion of food energy provided by fat ( r=−0.53; P< 0.0001) and (ii) dietary fibre intake per 4.18 MJ/day ( r=−0.48; P<0.0001). In men the intake of thiamin, vitamin E, iron, zinc, copper and magnesium per 4.18 MJ significantly decreased ( P<0.05) as sugar intake as a percentage of total energy intake (%E) rose. In women, micronutrient intake expressed per 4.18 MJ showed a significant negative trend with sugar intakes as %E for all of the micronutrients investigated, except for vitamins D and E. Body mass index tended to decrease as sugar intake rose, but this difference did not reach significance. Conclusion: The findings of this study did not demonstrate an association between sugar intake and obesity in older South Africans. However, a nutrient-diluting effect of sugar intake on both micronutrient and fibre intake was observed and needs to be addressed in nutrition intervention strategies for this age group.