Deficiencies of nutrients, including vitamins, minerals and polyunsaturated fatty acids, and surpluses of food items, such as sucrose and artificial food additives, have not convincingly been shown to be involved in the etiology of ADHD. At group level, there is no conclusive evidence supporting dietary interventions for the treatment of ADHD. The identification of a role of food compounds in ADHD is hindered by the complex and ill-defined nature of ADHD. In view of the heterogeneity of the disorder, potential therapeutic benefits of nutritional interventions could be confined to subpopulations of children with ADHD as yet unidentified. The cumulative benefits of the range of ingredients comprising healthy diets may result in better outcomes compared to a supplementation of individual nutrients. Diet and nutrition interact with other lifestyle factors, such as physical activity, and the interrelationship between nutrition and lifestyle should play a more prominent role in research on treatment approaches to ADHD. The few-foods or oligoallergenic diet allows the design of individually tailored diets and may offer treatment opportunities in subgroups of children diagnosed with ADHD. Further research is required to demonstrate the utility of nutrition-related interventions alone or in combination with other treatment approaches in ADHD.