I'm on phase 3 ( Lifestyle maintenance) of the Fat Flush Plan, (Ann Louise Gittleman). This is not a list of a day's menu's, but rather serving portion sizes. We're encouraged to eat 4-6 oz of cooked lean protein twice a day. We can also have several servings of 1 cup cooked or fresh low glycemic veggies,(broccoli, spinach, cauliflower, snow peas, summer squash, etc). A 1/2 cup serving, or two, of high glycemic veggies, (potatoes, sweet potatoes, carrots, beets, rice, winter squash, etc) unlimited veggies are celery, lettuce, bokchoy, radishes, etc,. One slice bread, unless you're making a sandwich, 2 low glycemic fruits (apple, pear, peach, orange) - or 1 cup of any berries, a small banana, or a small serving of any melon or tropical fruit (that one's hard to keep at a small serving, LOL), 1-2 Egglands' Best eggs, (they're high in healthy Omega-3's) Of course, this list doesn't include all foods or condiments but you can use your own judgement on how much or what you want of them. You can find a glycemic index of foods online to help you get started with your choices.
Basically, it depends upon your personal digestive system. Eat slow and chew your food well and quit when you feel satisfied, no longer hungry. It takes up to 20 minutes to feel full. If, after 20 minutes, you still feel a little hungry, snack on something healthy, not junk food full of refined sugar, as that will spike your insulin and then when it drops a short time later, you'll feel hungry again even tho you just had a good meal earlier.
Listen to your body, it will tell you when it's had enough. Don't go by what tastes good as your taste buds are never fully satisfied. I never eat chips out of the bag or ice cream in a large bowl as my taste buds want MORE even tho my stomach says "enough". The healthier food choices will leave you feeling more satiated and not stuffed or starving shortly after a meal.
Even though you are on a 2000 calorie diet right now, you can still enjoy a dessert now and then, just make it a small serving. Eat whole fruits, not juice, as the fiber in the fruit will slow down the absorption of the natural fruit sugar and not cause an insulin spike as the juice will do. I enjoy a whey protein/frozen fruit smoothie with a tbsp of healthy Barleans high lignon flaxoil. You can add fresh or frozen yogurt to it.
Don't drink a lot of fluids during your meal as that will dilute the digestive juices and minimize proper digestion of your food. One exception is pure cranberry juice (not the grocery store brand). It actually aids in digesting food.
I'm so very proud of you both for overcoming anorexia and striving to maintain a healthy lifestyle. My suggestions to you are not for weight loss but for maintenance and are meant to be a guideline for healthy choices and serving sizes, as you requested. God bless.