First of all, both heredity and environment will affect a person's body shape and weight. Genetic factors refer to genes that a person inherits from his parents, which will affect a person's body shape and metabolic rate. Environmental factors include eating habits, exercise, lifestyle and so on. These factors will affect a person's weight and body shape.

In your case, your parents and your lifestyle may have an impact on your body shape. Your parents may have inherited some genes that make it easier for you to stay slim. Besides, your parents are very concerned about your diet and exercise when you grow up, which also helps you keep a healthy figure.

However, you also need to be careful not to restrict diet and exercise excessively, which will lead to health problems. Excessive restriction of diet may lead to insufficient nutrition and affect health. At the same time, proper exercise can help you maintain a healthy weight and body shape.

In a word, your body shape is influenced by both genetic and environmental factors. Your parents' genes and lifestyle may affect your body shape, but you also need to pay attention to maintaining a healthy diet and exercise habits to maintain a healthy weight and body shape.