Welcome to the rest of your life! You don't have to incorporate all the recommendations of this phase at once, but do the best you can. Consider the way you eat and exercise as a work in progress.
Maintain the changes you achieved in Phases 1 and 2, and now try and incorporate more and more healthful foods, which will provide fiber, vitamins, minerals and phytonutrients that can help stave off chronic diseases. Keep whittling out foods that are high sources of saturated fat, added sugar and sodium, and skip foods with partially hydrogenated oil altogether. Put "anything goes" calories toward "luxury foods" that are indulgent but still have something to offer, such as dark chocolate, full-fat cheese and yogurt, pizza with whole grain crust, or a glass of wine.
Try to focus your diet primarily on vegetables, but go easy on potatoes, corn and peas because they're as starchy (and about as caloric) as grains. Also incorporate more beans into your diet a couple times a week—they are superfoods in terms of nutrition. At least two servings of fruit are recommended a day. Also, continue to replace refined grains with whole ones. Ideally, 75 percent of the grains in your diet will be whole.
Keep pushing yourself to increase your activity. Exercise will help you maintain the weight loss you've achieved and allow you to eat more food without regaining. It will also help slow down the aging process. Weigh yourself no more than once a week and no less than once a month.