Associations between Intake of Dietary Sugars and Diet Quality: A Systematic Review of Recent Literature

Abstract

Understanding the relationship between the intake of sugars and diet quality can inform public health recommendations. This systematic review synthesized recent literature on associations between sugar intake and diet quality in generally healthy populations aged 2 years or older. We searched databases from 2010 to 2022 for studies of any design examining associations between quantified sugar intake in the daily diet and dietary indexes (DIs) or micronutrient intakes. Different sugar types and diet quality measures were analyzed separately. We converted DI results to Pearson's r correlations and grouped indexes with or without a free or added sugar component to facilitate cross-study comparisons. Meta-analysis was deemed inappropriate. From 13,869 screened records, we included 27 cross-sectional studies. NUQUEST risk of bias ratings were neutral (n = 18 studies) or poor (n = 9), and strength of evidence by the GRADE approach was very low due to study design. Most studies reported negative associations for added and free sugars with diet quality indexes (r ranging from -0.13 to -0.42) and nutrients of public health concern (fiber, vitamin D, calcium, potassium), while associations with total sugars were mixed. Due to cross-sectional study designs, the clinical relevance of these findings is unclear. Prospective studies are needed to minimize confounding and inform causal relationships.

Keywords: diet; diet quality; dietary fiber; dietary sugars; micronutrients; nutrition assessment; nutritional requirements; nutritive sweeteners; trace elements; vitamins.

Figure 1

Flow diagram of the study search and selection process.

Figure 2

Forest plot with correlations for intake of added sugars and dietary indexes, where higher dietary index scores indicated higher diet quality [15,21,26,28,29,33,35].

Figure 3

Forest plot with correlations for intake of free sugars and dietary indexes, where higher dietary index scores indicated higher diet quality [32,33,34,37].

Figure 4

Forest plot with correlations for intake of total sugars and dietary indexes, where higher dietary index scores indicated higher diet quality [20,32,37].