Milk and dairy consumption is positively associated with height in adolescents: results from the Israeli National Youth Health and Nutrition Survey

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.