Question: A study is planned to compare two weight loss programs in patients who are obese. The first program is based on restricted caloric intake and the second is based on specific food combinations. The study will involve twenty participants and each participant will follow each program. The programs will be assigned in random order (i.e., some participants will first follow the restricted calorie diet and then follow the food combination diet, while others will first follow the food combination diet and then follow the restricted calorie diet). The number of pounds lost will be compared between diets. What is the main strength of this type of study?