Inclusion Criteria:  Target: Among the patients who have undergone thyroidectomy, patients who are interested in weight management and can use the Noom app by themselves or with the help of neighbors. The patient has 23 or more BMI at the time of enrollment. In The Situational Motivation Scale (SIMS), a total of five stages of synchronization level of 68 or higher, which is the top 40% of the 112 points (1st stage: pre-consumption stage; stage 2: deliberation stage; stage 3: preparation stage; stage 4: action stage) The patient agreed about participating in this study.  Exclusion Criteria:  The patient was diagnosed with chronic diseases (hepatic disease, kidney disease, diabetes, etc.). In the case where there is no member who can support among family members, The patient who is not a smartphone or has difficulty using digital technology. When it is difficult to lose weight (pregnancy and pregnancy preparation, breastfeeding, and less than 12 months after childbirth) If the patient has a history of psychiatric illness (eating disorder, depression, etc.). If the patient is taking diet-related drugs or health supplements, or treatments. If there is a restriction on physical activity (not allowed to exercise for more than 30 minutes a day).