The association of body mass index and dietary fat intake with autism in children: a case-control study

Purpose Deficiencies or imbalances in dietary fat intake may influence on mental and neurological functions of children with autism spectrum disorders (ASD). This study aims to compare body mass index (BMI) and the amount of fatty acids intake in the autistic patients with the comparison group. Design/methodology/approach This case-control was carried out on 200 randomly selected children from 5 to 15 years old (100 autistic patients as the case group and 100 healthy children as the comparison group) in Tehran, Iran. The food frequency questionnaire (FFQ) was used to assess the intake of calorie, macronutrients and different types of dietary fatty acids including saturated fatty acids (SFA), monounsaturated fatty acids (MUFAs), poly unsaturated fatty acids (PUFAs), linoleic acid (LA), α-Linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and trans fatty acids. Findings The autistic patients had higher BMI, birth weight and mother’s BMI compared to the comparison group (All p < 0.01). No significant difference was found in the amount of dietary calorie, protein, carbohydrate and total fat intake between two groups. The risk of ASD was associated with higher intake of MUFAs (OR: 3.18, CI%:1.13–4.56, p = 0.04), PUFAs (OR: 4.12, CI95%: 2.01–6.25, p < 0.01) and LA (OR: 4.76, CI95%: 1.34–14.32, p < 0.01). Originality/value The autistic children had higher BMI and higher intake of unsaturated fatty acids except for omega-3 fatty acids. Further longitudinal studies are warranted.