Adverse reactions to foods are classified according to the presence or absence of involvement of the immune system, which may or may not include the production of immunoglobulin E (IgE) antibodies. This review focuses on the epidemiology, diagnosis, and management of adverse food reactions, primarily in adults, and excluding celiac disease and lactose intolerance. Reported reactions to foods are often believed to be manifestations of a food allergy; however, IgE-mediated food allergy only affects 1% to 4% of adults, with seafood, tree nuts, peanuts, fruits, and vegetables being the most common triggers. Diagnosis is challenging and most commonly achieved through careful evaluation of clinical history followed by elimination and reintroduction or challenge with the suspected offending food. With acute-onset allergic reactions, estimation of food-specific IgE antibodies is frequently used to confirm or refute the diagnosis. Recent developments, such as single allergen assays, enhance the diagnosis of IgE-mediated food allergy, but the gold standard remains oral food challenge. Despite recent advances in the management of food allergy, including the promotion of oral tolerance, the mainstay of management is still the avoidance of food triggers. Dietary management can be compromised by nutritional inadequacy, accidental exposure, food labeling, and quality of life or adherence issues. It is essential that adults with confirmed food allergy receive optimal nutrition and dietetic support to enable them to manage their condition.