Diet has a significant impact on our life and is crucial to our health. Nutritional disease refers to any disease or condition that is caused by a lack of nutrients that causes illness in people. Adults are more likely to develop diet-related ailments as they become older, such as hypertension (high blood pressure), heart disease, cancer, and/or osteoporosis. Although older persons are more prone than younger adults to require dietary changes to control disease, the diet should nevertheless reflect the older adult's tastes. Diets for the elderly should be tailored to the individual rather than attempting to change their eating habits. Dietary deficiencies or excesses, obesity and eating disorders, as well as chronic diseases, are all examples of nutritional diseases. Hereditary metabolic conditions that respond to dietary treatment, the interaction of foods and nutrients with medications, food allergies and intolerances, and developmental abnormalities that can be avoided by diet are all examples of nutritional diseases.