ObjectiveTo evaluate the dietary patterns in a group of patients diagnosed with attention deficit hyperactivity disorder (ADHD) and under treatment with extended-release methylphenidate (MPH-ER). Material and methodsA nutrition survey (food intake recall for three consecutive days) was carried out on 100 patients diagnosed with ADHD and under treatment with MPH-ER, and in 150 healthy children (control group). Calorie and nutrient intake, as well as nutrition status, were evaluated and compared in both groups. ResultsThe mean MPH-ER dose was 1.02mg/kg/day. Nutritional status in the ADHD group was significantly lower (P < .05) than in control group. The consumption of cereals, meat, pulses and fruits in the control group was significantly higher (P < .05) than in ADHD group. Calorie intake in the mid-morning snack, lunch and afternoon snack was significantly higher (P < .05) in the control group. Calorie intake at supper was significantly higher (P < .05) in the ADHD group. Total calorie intake, as well as protein, carbohydrates, fat, fibre, calcium, iron, magnesium, zinc, selenium and phosphorous, thiamine, niacin, vitamin B6 and folate intake in the control group was significantly higher than in ADHD group. ConclusionsTreatment with MPH-ER substantially modifies the percentage distribution of calorie intake of the different meals. The daily calorie and nutrients intake in patients under treatment with MPH-ER is, generally, lower than in the healthy population of a similar age. Nutrition education should be provided, along with multimodal treatment, to the patients and/or their families.