Background: Despite the universal iodization of salt in Ethiopia, iodine deficiency disorders remain a major public health problem and continued to affect a large segment of the population. It is thus essential to assess factors contributing to the unacceptably high endemic goiter rate in the country and avail evidences for further additional interventions. In line with this, we examined the association of diet and iodine deficiency among school aged children in Ethiopia.

Method: A school based cross sectional study was conducted among 767 school children in southwest Ethiopia February to May 2016. Relevant socio-demographic and other important health information were collected using a pre-tested structured questionnaire through interview. Dietary pattern was measured using modified Hellen Keller’s food frequency questionnaire. Iodine deficiency was diagnosed based on urinary iodine concentrations level and total goiter rate according to the World Health Organization threshold criteria. Multivariate linear regression was used to identify dietary factors that affect urinary iodine level.

Result: Of the 767 sampled children, 12% and 4% of school children have grade 1 and grade 2 goiter respectively, making the total goiter rate 16%. While the prevalence of iodine deficiency based on urinary iodine concentration is 58.8% of which 13.7 % had severe, 18.6% had moderate and 26.5% had mild form. The proportion of children who consumed taro/godere, banana, corn, Abyssinian cabbage, and potato respectively at daily bases 57.8%, 53.1%, 37.9%, and 31.2%, respectively. Age (β= -0.7, 95%CI= (-1.1, -0.4)), sex (β= -22.3, 95%CI= (-33.8, -10.8)), consumption of godere/taro root (β= -27.4, 95%CI= (-22.9, -31.8)), cabbage (β= -11.7, 95%CI= (-5.7, -17.6)), Abyssinian cabbage (β= 12.4, 95%CI= (6.7, 18.2)), and banana(β= 5.6, 95%CI= (0.01, 11.2))  significantly associated with urinary iodine level.

Conclusion: Iodine deficiency is still an important public health problem in southwest Ethiopia. Over-consumption of goitrogenic foods and under-consumption of iodine-rich foods were prevalent and associated with lower urinary iodine level. Therefore, dietary counseling apart from universal salt iodization is recommended.