The calorie requirement for a person can depend on factors like lifestyle, environment, weight loss/gain goals, physical activity, etc. Even though your genetic makeup may have a say in this, it is difficult to recommend the calorie intake solely based on genetic reports. For example, identical twins are closely related based on their genes; however, individual calorie requirements will vary depending upon how active their lifestyle is. The calorie requirement for a physically active twin may be significantly more than a twin leading a sedentary lifestyle.