Abstract:

Purpose Milk consumption is associated with increased height primarily in early childhood. However, in adolescents, data are scarce with inconsistent results. Since height is a proxy for overall health and well-being, this study evaluated the association of dairy intake with height in adolescents. Methods Students in 7th-12th grades, participating in the 2015-2016 Israeli Health and Nutrition Youth Survey, a school-based cross-sectional study, completed self-administered questionnaires, including a semi-quantitative food frequency questionnaire (n = 3529, 48% males, 15.2 +/- 1.6 years). Anthropometric measurements were also performed. Dairy servings were calculated as the calcium equivalent of 1 cup of milk, and consumption was divided into four categories from very low (< 1 serving/day) to high (3 + servings/day). BMI- and Height-for-age z scores (HAZs) were calculated according to WHO growth standard; relatively short stature (RSS) was defined as HAZ < - 0.7 SD (< 25th percentile). Multivariable linear and logistic regression analyses were performed to evaluate the association of dairy intake with HAZ and prevalence of RSS, respectively. Results Median consumption of dairy products was 2 servings/day, 1.4 from unsweetened products (milk, cheese and yogurt). Controlling for age, sex, BMI-z-score and socioeconomic status, each increment of unsweetened dairy intake was associated with on average 0.04 higher HAZ (equivalent to 0.3-0.4 cm, p < 0.05), and with reduced risk for RSS: OR 0.90, 95%CI: 0.84, 0.97, p < 0.01. No such associations were found with sweetened dairy products. Conclusion Consumption of unsweetened dairy products (3-4 servings/day) appears to contribute to achieving growth potential in adolescents. Intervention studies are necessary to determine the causal relationship between dairy intake and linear growth.