The DBI-16 is an effort to evaluate dietary quality more rationally under the guidance of the Dietary Guidelines for Chinese Residents published in 2016. It contains 8 food indicators, namely (range of values) (1) Cereals (−12–12) (2) Fruits and vegetables (vegetables 6-0, fruits 6-0); (3) Dairy and soybeans (dairy 6-0, soybeans 6-0); (4) Animal foods (meat 4–4, fish 4-0, eggs 4–4); (5) Pure energy foods (cooking oil 0–6, alcohol 0–6); (6) Condiments (sugar 0–6, salt (0–6); (7) Varied diet (−12–0); and (8) water (−12–0). If data on water consumption are lacking, they could be ignored in the evaluation. A varied diet was calculated based on 12 food groupings: rice, pasta, coarse grains and potatoes, dark vegetables (≥500 μg carotenoids per 100 g of vegetables), light vegetables (<500 μg carotenoids per 100 g of vegetables), fruits, soy products, dairy products, livestock, poultry, eggs, and fish and shrimp.
The low bound score (LBS) of the scale is the sum of the absolute values of all negatively assigned index scores, reflecting inadequate dietary intake, and ranges from 0 to 60. The high bound score (HBS) of the scale is the sum of all positively assigned index scores, reflecting excessive dietary intake, and ranges from 0 to 38. The dietary quality distance (DQD) is the sum of the absolute values of each index, reflecting dietary imbalance. A score of 0 indicates good dietary intake (Suitable), a score that is below 20% of the total score indicates good dietary intake (More suitable), and a score that is 20–40% of the total score indicates acceptable dietary intake (Low level), a score that is 40–60% of the total score indicates poor dietary intake (Medium level), and a score that is more than 60% of the total score indicates the worst dietary intake (High level), also defined as poor dietary quality [30 (link)]. Data on water and sugar were lacking, so scores for added sugar and drinking water were not accounted for [31 (link)].