Overview A child's diet can increase anger by contributing to certain conditions. A lack of healthy foods, allergic reactions or harmful substances in the foods your child eats could be behind mood swings, hyperactivity, tantrums, depression and anger. Anger is not always a bad emotion, but it can lead to aggressive or out of control behavior if the underlying cause is not addressed. Food Additives Food additives are chemicals that manufacturers add to food to increase their shelf-life and to improve flavor. Eating foods with additives might contribute to anger in children with Attention Deficit Hyperactivity Disorder, ADHD. According to an article published in March 2000 in the Center for Science in the Public Interest's Nutrition Action Health Letter, studies have shown children who ate foods with additives like food dyes demonstrated worse behavior. These children also showed improvement when they ate a diet free from additives. Common food additives that may be harmful in general include monosodium glutamate, MSG, caffeine, saccharin and nitrates or nitrites. Omega-3s Anger is a common problem with children who are depressed or suffer from other psychiatric disorders. Depressed children have a harder time controlling and expressing their anger than children who are not depressed, according to a study published in the "Journal of American Academy of Child and Adolescent Psychology" in March 1995. Eating foods with omega-3 fatty acids may help individuals suffering from depression, according to a study led by investigators at McLean Hospital in Massachusetts. Foods high in omega-3s include walnuts, cold-water fish and canola oil. The reason why these foods help depression is unknown. Food Allergies Food allergies can cause behavioral problems like irritability and sleep disturbances as well as contribute to ADHD. In fact, kids eating foods they are sensitive to is the main cause of ADHD, according to an article published in March 2011 by NPR. Additionally, studies have shown that children who ate certain foods -- like the common food allergy triggers, wheat, soy and milk -- demonstrated worse behavior, according to the Nutrition Action Health Letter. Some children who eliminated trigger foods from their diets saw improvements in behavior. Other possible foods that may cause problems include oranges, eggs, chocolate and corn. Other Causes Diet is not the only potential cause of anger in children. Feelings of stress or frustration stemming from learning problems, a lack of physical coordination or skills or problems with family or friends can also cause anger. Illness or divorce are two common examples that dietary modifications cannot help.