Genetic characteristics come from our parents, but we also have inherited properties from our ancestors. It is called genetic heritage. Our genes do not only have an impact on our appearance, but it also effects the health. Genes that are related with nutrition can affect the risk of developing chronic diseases such as diabetes, heart disease, and can also affect the progression and severity of the disease. Personalized nutrition is important both to sustain health and to reduce the risk of malnutrition or diseases.

Health effects of foods may vary according to our genetic characteristics. For example; the blood cholesterol, blood lipids or uric acid levels of some individuals who eat same amount of the same foods may be normal while others may be high. One of the two people at the same age, whose eating habits and physical activity intensities are similar, may have ideal body weight while the other may be obese. All these differences are due to the relationship between the genetic characteristics, nutritional status and lifestyle of the individual.

Some genes play a role in the choosing of food and use of nutrients in the body. For example, thrifty genes provide an increase in fat stores during the fasting period and therefore have higher advantage of keeping us alive compared to other genes. Although these 'thrifty' genes are suitable for fasting but it is a problem for individuals who can constantly reach food.

Each person is genetically predisposed to certain diseases. Although there is genetic predisposition in some diseases, our immune system may prevent the emergence of these diseases. For example, individuals with a family history of chronic disease may develop diseases at later ages as a result of weak immune system. Nutrition plays an effective role in reducing the risk of these diseases associated with immunity. Environmental factors as well as genes are effective in maintaining health and in the emergence of diseases. Genetic differences and diversity among individuals affect their nutritional requirements, nutrition status and hence their health status. While a small amount of food intake is a risk for some individuals, it may not be for others; on the contrary, it may be harmful for some while providing some benefit

Since our genetic characteristics and lifestyle affect our health and metabolic responses, nutrition should be personalized. As a result, the nutrients we consume have an effect on our genes as well as our genes can be affected by our nutrition and cause the emergence of the diseases. Therefore, today the relationship between nutrition and genes has become an increasingly attractive topic, and perhaps in the future, nutrition that are specific to genetic characteristics will become widespread, and this will lead to an aspect preventive medicine