Trends in Diet Quality and Increasing Inadequacies of Micronutrients Vitamin C, Vitamin B12, Iron and Potassium in US Type 2 Diabetic Adults

BACKGROUND: Prevalence of diabetes was high and rose significantly in the US between 1999 and 2018. A healthy dietary pattern that provides micronutrient adequacy is one of the most important lifestyle choices for battling the progress of diabetes. Yet, the patterns and trends of diet quality of the US type 2 diabetes are understudied. OBJECTIVES: We aim to examine the patterns and trends of diet quality and major food sources of macronutrients of US type 2 diabetic adults. METHODS: The 24 h dietary recalls of 7789 type 2 diabetic adults, comprising 94.3% of total adults with diabetes from the US National Health and Nutrition Examination Survey cycles (1999–2018), were analyzed. Diet quality was measured by the total Healthy Eating Index (HEI)-2015 scores and 13 individual components. Trends of usual intakes of vitamin C (VC), vitamin B12 (VB12), iron, and potassium and supplements from two 24 h recalls were also examined for type 2 diabetic population. RESULTS: Diet quality of type 2 diabetic adults worsened between 1999 and 2018 while that of US adults of general population improved based on the total HEI 2015 scores. For people with type 2 diabetes, consumption of saturated fat and added sugar increased while consumption of vegetables and fruits declined significantly, although consumption of refined grain declined and consumption of seafood and plant protein increased significantly. In addition, usual intakes of micronutrients VC, VB12, iron, and potassium from food sources declined significantly during this period. CONCLUSIONS: Diet quality generally worsened for US type 2 diabetic adults between 1999 and 2018. Declining consumptions of fruits, vegetables, and non-poultry meat may have contributed to the increasing inadequacies of VC, VB12, iron, and potassium in the US type 2 diabetic adults.