In the clinic for eating disorders and obesity, we often come across failure to change eating habits. Despite a strong desire to lose weight, obese people generally fail in their attempts to change their eating habits, even when guided by competent professionals. In view of this, the need for more refined clinical research based on effective instruments seemed obvious to us. I chose impulsivity for my studies because this personality trait strongly interferes with an individual’s ability to tolerate changes in habits, especially eating habits, which have a strong emotional charge. This is a report on the protocol developed for the clinical investigation of impulsivity in adolescent patients at the nutrology outpatient clinic of a medical school. In addition to the instruments recommended in the literature, the Pallographic Test was used, a graphic test that is easy to apply and eliminates the biases of Likert-type scales. This book is aimed at those studying the clinical investigation of compulsions and impulsivity and psychological assessment.