Cardio exercise every other day, such as brisk walking, jogging, trampolining, cross country skiing, running, or cardio/aerobic dancing.
Add to cardio exercise, weight/strength training two to three times per week.
Change your eating habits and count carbohydrates and calories.
Plus cut out or strictly limit all refined processed carbohydrates they are a major cause of weight gain, obesity, and many diet related diseases (see the list of these foods further down this page, listed under Related Questions).
Drink plenty of fresh water and stay away from white food and dairy products.
Food addiction is as dangerous as other addictions, make it a habit not to eat until you are hungry. Many people are addicted to refined processed carbohydrates.
For more information, see the page links, further down this page, listed under Related Questions.