A healthy BMI would be between 18.5 and 24.9, meaning a healthy weight for you would be between 108 and 145. Now, take into consideration, this is just a medical opinion. If you want to lose weight, you need to take small steps. Make small goals for yourself. Change little things like cutting out sweets for a day or taking the stairs instead of the elevator. To lose weight, you need to eat healthy foods and exercise 3-5 hours a week.