Prevalence of lactose intolerance and its association with breakfast consumption in Iranian adolescents

Abstract
Lactose intolerance (LI) is a disturbing gastrointestinal disorder with a high prevalence in all parts of the world, especially in Asian countries. The purpose of this study is to investigate the prevalence of LI in students from Zabol, Iran. Based on cluster random sampling method, 887 subjects were selected for the study. Of all, 54.7 per cent of the students were boys. The mean (±SD) of age, weight and body mass index (BMI) for participants were 13.27 ± 1.14 years, 42.12 ± 10.25 kg and 18.7 ± 3.9 kg/m2, respectively. LI was assessed using a validated self-administered questionnaire. After measuring the anthropometric indices, students were asked to ingest 200cc of milk. The questionnaires were completed 2 h after the ingestion of milk. In total, 25.8 per cent of the adolescents had LI. Of all, 1, 4.6, 11, 30.2 and 53.2 per cent of affected students had severe, relatively severe, moderate, relatively mild and mild LI, respectively. The association between LI and gender, and BMI was not significant (p > 0.05 for both); however, the association between LI and the history of LI in parents (OR = 2.06; 95 per cent CI: 1.47-2.88; p < 0.001), and breakfast consumption was significant (OR = 1.49; 95 per cent CI: 1.04-2.14; p = 0.028). Although the prevalence of LI is noticeable, majority of adolescents had mild and relatively mild LI. Parents’ history and breakfast consumption are related to the rate of LI prevalence. Appropriate strategies should be considered to prevent breakfast skipping.