Association between quality and quantity of carbohydrate intake with selected anthropometric indices among primary school girls in Kerman city, Iran: a cross-sectional study

The school-age is a crucial period of physical and cognitive growth, which requires an assessment of dietary intake and its influence on body weight and height. This study aims to determine the association between the quality and quantity of carbohydrate intake with selected anthropometric indices in primary school girls in Kerman City, Iran. This cross-sectional study was conducted on 330 primary school girls ages 6–12 years in Kerman. We used a validated and reliable dish-based 185-item food frequency questionnaire to evaluate people’s food intake. We assessed the amount of carbohydrates in children’s diets as the percentage of daily calories and grams per day. We used dietary fiber intake (grams/day), the glycemic load, the ratio of whole grain to total grain, and the ratio of solid carbohydrates to total carbohydrates to assess carbohydrate quality. Height, weight, and arm circumference were measured. We calculated body mass index (BMI) by dividing the weight in kilograms by the height in centimeters squared. We used the World Health Organization z-scores charts for girls 5 to 19 years old to assess z-scores for BMI-for-age (BAZ), height-for-age (HAZ), and weight-for-age (WAZ). Socioeconomic status and physical activity were assessed. We used ANOVA and ANCOVA statistical tests to assess the association between anthropometric indices and carbohydrate quantity and quality parameters. Participants with the highest amount of carbohydrate intake had significantly higher anthropometric indices, including arm circumference, BMI-for-age z score (BAZ), and Height-for-age z score (HAZ) (p < 0.001, p < 0.001, and p = 0.009, respectively). With the increase in glycemic load (GL) and dietary fiber intake, anthropometric indices including arm circumference (GL: p < 0.001, Fiber: p < 0.001), BAZ (GL: p < 0.001, Fiber: P < 0.001), and HAZ (GL: P = 0.009, Fiber: p < 0.001) increased significantly. We concluded that there was a positive association between the amount of carbohydrate intake and anthropometric indices (MUAC, BAZ, and HAZ). Also, with the increase in glycemic load and dietary fiber intake, the anthropometric indices including MUAC, BAZ, and HAZ increased.