Balanced carbohydrate ratios are associated with improved diet quality in Australia: A nationally representative cross-sectional study

Carbohydrate quality influences major health outcomes; however, the best criteria to assess carbohydrate quality remain unknown. The objectives were to: i) evaluate whether a diet that meets a carbohydrate ratio (simple, modified or dual ratio) is associated with higher nutrient intakes and diet quality, and ii) model the impact of substituting carbohydrate foods that meet the proposed ratios in place of foods that do not, on nutrient intakes. A secondary analysis of cross-sectional data from the 2011-12 Australian National Nutrition and Physical Activity Survey. National data from participants aged 2 years and older (n = 12,153). Ratios were defined as (i) simple ratio, 10:1 (10g carbohydrate:[greater than or equal to]1g dietary fiber); (ii) modified ratio, 10:1:2 (10g carbohydrate:[greater than or equal to]1g dietary fiber:[less than or equal to]2g free sugars); and (iii) dual ratio, 10:1 & 1:2 (10g carbohydrate:[greater than or equal to]1g dietary fiber & [less than or equal to]2g free sugars per 1g dietary fiber). Ratios were compared to nutrient intakes obtained via automated multiple-pass 24-hour dietary recall and diet quality calculated using the Australian Healthy Eating Index. Ratio adherence was highest for simple (50.2% adults; 28.6% children), followed by dual (40.6% adults; 21.7% children), then modified (32.7% adults; 18.6% children) ratios. Participants who met any ratio reported higher nutrient intake and diet quality compared to those who failed to meet the respective ratio (P < .001 for all), with the greatest nutrient intakes found for those who met modified or dual ratios. Dietary modelling improved nutrient intakes for all ratios, with the greatest improvement found for the dual ratio. All carbohydrate ratios were associated with higher diet quality, with a free sugars constraint in the dual ratio providing the greatest improvements.