BackgroundAggression is one of the most prevalent behavioral disorders in men.ObjectiveThis study aimed to assess the possible association between dietary intake of food groups and aggression in middle-aged married men.MethodsThis case-control study included 336 participants (168 men with aggressive behaviors and 168 healthy controls) aged 35–55 years. Demographic information was collected using a socio-demographic questionnaire. A food frequency questionnaire was used to investigate the diet group intake last year. Based on the normality of the data distribution, Independent t-tests and Mann-Whitney tests were used to compare quantitative variables between the two groups. Categorical variables were compared between cases and controls using the Chi-squared test. Logistic regression analysis was used to examine the possible association between food intake and aggression.ResultsCompared to controls, aggressive men had significantly higher mean weight, height, and waist circumference (WC), p = 0.007, p = 0.001, and p = 0.043, respectively. After adjusting WC, energy intake, and educational level, in Model 1, intake of milk, cheese, poultry, red meat, legumes, egg, fruits, and vegetables had a significant protective role on the occurrence of aggression, (Odd Ratio (OR) = 0.36; 95% (Confidence Interval (CI) = 0.204, 0.670; P = 0.001), (OR = 0.440; 95% CI = 0.284, 0.781; P = 0.005), (OR = 0.621; 95% CI = 0.284, 0.781; P = 0.046), (OR = 0.358; 95% CI = 0.198, 0.647; P = 0.001), (OR = 0.434; 95% CI = 0.243, 0.773; P = 0.005), (OR = 0.411; 95% CI = 0.229, 0.736; P = 0.003), (OR = 0.332; 95% CI = 0.180, 0.614; P < 0.001), (OR = 0.310; 95% CI = 0.168, 0.572; P < 0.001), respectively.ConclusionsLower WC and a diet containing high-quality protein, fruits, and vegetables can have a protective role against aggression and are recommended for men with an aggressive mood. This diet can affect plasma levels of tryptophan and, therefore, brain levels of serotonin.