Dietary Trends in Energy, Carbohydrate, Protein, Fat, Sodium and Potassium Intake by Urbanicity Index in Chinese Adolescents from 1991 to 2011
Authors: Yu Alice Yunzi Ling , Lopez‐Olmedo Nancy , Popkin Barry 
Published: November 2023

BACKGROUND

Little is understood about trends in adolescent diet in transitional countries. This study examines dietary change in Chinese adolescents aged 12 to 17 years old. Specifically, changes in macronutrient composition of diet and intake levels of sodium and potassium were analyzed for temporal trends.

METHODS

Dietary data was collected from the China Health and Nutrition Survey using individual level, consecutive 3‐day 24‐hour recalls from survey years 1991 (n=489), 2000 (n=677), and 2011 (n=253). The urbanicity index used in this study diverges from the commonly used method of population density as a determination of urbanization. This urbanicity index is a continuous scale constructed by 12 constructed dimensions, including education, health infrastructure and population density, and classified by tertiles for analysis purposes. Sodium and potassium were analyzed and compared as Na/K ratios. Linear regression models were constructed to predict means with their respective standard errors of macronutrients (carbohydrates, protein, and fat) as well as sodium/potassium ratio intakes and adjusted for covariate sociodemographic variables.

RESULTS

From 1991 to 2011, per capita energy intake steadily decreased in low and middle urbanicity cohorts (2592 kcal/d to 1691 kcal/d, p<0.001; 2382 kcal/d to 1804 kcal/d, p<0.001 respectively). Similarly overall, the high urbanicity cohort showed a significant decrease in daily caloric intake between 1991 and 2011 (2358 kcal/d to 1938 kcal/day, p<0.001). Percent carbohydrate intake of daily calories decreased steadily in the low urbanicity cohort (68.1% to 57.9%, p<0.001). Middle and high urbanicity cohorts showed non‐continuous but significant overall decreases in percent carbohydrate intake from survey year 1991 to 2011 (61.7% to 53.6%, p<0.002; 62.0% to 53.2%, p<0.014). The low urbanicity cohort also displayed a steady increase in percent fat intake of daily calories (20.8% to 29.6%, p<0.001 respectively). The middle urbanicity cohort showed non‐continuous but significant increase in percent fat intake between 1991 and 2011 (26.1% to 33.6%, p<0.004). For percent protein intake of daily calories, the low urbanicity cohort showed steady increase (11.0% to 12.5%, p<0.001), while the high urbanicity cohort showed non‐continuous but significant increase from 1991 to 2011 (12.5% to 13.7%, p<0.0002). The Na/K ratios steadily decreased in the low urbanicity cohort (5.02 to 2.65, p<0.004). Also a non‐continuous but significant decrease in Na/K ratio was observed for middle urbanicity and high urbanicity cohorts (4.21 to 3.49, p<0.0002; 3.41 to 2.33, p<0.0008).

CONCLUSION

The Chinese diet for adolescents is changing remarkably fast as activity and energy intake overall decline. A shift from a high carbohydrate intake to one higher in the proportion of energy from fat and protein has occurred. Sodium‐potassium ratios also show a positive health effect of a decreasing trend across all levels of urbanicity.

Support or Funding Information

University of North Carolina at Chapel Hill Nutrition Department