Nutrition and dietary habits is one of the determinant factor on glycemic control of diabetes mellitus. This study aims to investigate the association between type 1 diabetes mellitus (T1DM) and diet in the first two years of life as well as a select group of demographic variables.

This case-control study was conducted on 76 children with T1DM and 209 non-diabetic children selected through convenience sampling from the population of people visiting the community health centers of the city of Jahrom, Iran. The required data were collected by a questionnaire of diet and demographic information completed by the mothers of the children. The data were analyzed using logistic regression and adjusted odds ratio.

Finally, the results of multiple backward logistic regression showed that the studied factors had a significant association with T1DM (P < 0.05), including body mass index (BMI) less than 18 kg/m2 for mothers before pregnancy (OR: 4.4, 95% CI: 1.61 to 11.97), mothers without a history of diabetes (OR: 0.02, 95% CI: 0.001 to 0.60), mother’s weight before pregnancy (OR: 0.88, 95% CI: 0.84 to 0.91), mother’s excess weight during pregnancy (OR: 0.83, 95% CI: 0.75 to 0.93), exclusive breastfeeding for more than six months (OR: 0.19, 95% CI: 0.03 to 0.96), low weight gain in the first two years of life (OR: 6.98, 95% CI: 2.16 to 22.5), and the breastfeeding less than 12 months  (OR: 10.52, 95% CI: 1.62 to 66.64).

BMI less than 18 kg/m2 for mothers before pregnancy, low weight gain in the first two years of life, and breastfeeding less than 12 months increased the risk of developing T1DM in children.