Eat more to lose more: Your portions on the Fast Metabolism Diet

After a lifetime of deprivation diets, many of my clients kind of freak out when they see how much food I want them to eat. My book, The Fast Metabolism Diet, is a result of 20 years of clinical work, translating proven strategies from an office setting to a plan that can work for everyone. When you are first starting out the portion guidelines are confusing, so let’s talk about that.

It’s actually pretty simple: If your goal is to lose a larger amount of weight, you eat more food.

Your basic portion guidelines

  • If you want to lose less than 20 pounds, follow the standard portions outlined in the book.
  • If you want to lose more than 20 pounds, add 1/2 portion to that standard portion, so 1.5 portions.
  • If you want to lose more than 40 pounds, eat 1.5 portions but double the veggies.

For those of you who want to lose more than 40 pounds, note that this is a change from the book. The book advises adding another 1/2 portion for every additional 20 pounds of weight you want to lose. But there’s no upper cap in the book. That would mean, for a 100-pound weight-loss goal, the book guides you to eat 3 cups of oatmeal along with three cups of fruit (for Phase 1 breakfast). The problem? That’s too much food for a normal stomach to process in one sitting.

This change comes as a result of feedback from hundreds (actually thousands) of you. Double and triple portions are just way too much food – and because you’re trying to eat all your required items, not enough veggies are making it into your menus. So here’s the new rule again:

  • For a weight loss goal of more than 40 pounds, eat 1.5 portions of all the required meal and snack elements


  • Go nuts with veggies. Pack ’em in. You should not ever feel hungry. Eat more vegetables than you’ve ever eaten before.

Other common portion questions

Q. What’s the minimum amount of veggies I should eat?

A. I keep saying veggies are unlimited, and they are! Eat lots! Veggies are essential for fat burning and healing your metabolism. At the minimum (for 20 pounds or less), eat 2 cups of vegetables with meals that require a veggie, and one 1 cup with snacks (where required).

Q. I’m hungry on Phase 1. Should I eat more?

A. You should not feel hungry, and if you do, eat more veggies, even between meals. Keep in mind your vegetables don’t have to be raw. Try a baked sweet potato or steamed kale with garlic and lemon. 

Q. I’m confused about healthy fats and proteins on Phase 3. Do I need both or just one or the other?

A. For meals, you need both. For snacks, focus on the healthy fat plus veggies. This blog post covers that topic - Fat, Protein: Why you need both

Q. The app tells me I can have 4.5 tablespoons of oil in Phase 3. Really?

A. Yes, that would be the oil portion if you want to lose more than 20 pounds. Do you HAVE to pack in all 4.5 tablespoons? No. Keep in mind that is the full fat serving for an entire meal — if you use no other healthy fats at all. In reality, you can use 2 tablespoons for your veggie stir fry at dinner, and another 2 tablespoons in your salad dressing. Or maybe you’ll use 2 tablespoons for your stir-fry, but toss in 1/8 cup of sesame seeds (1/4 cup of seeds would be the full portion). See? That amount of oil doesn’t seem so crazy now, does it?

You can and should use your best judgment and use the healthy fats you need for your cooking. And you can mix and match healthy fats appropriately: Use 1/2 portion of hummus plus 1/4 avocado. Or 1/8 cup of raw almonds plus 1/8 cup of olives. Be creative and mix it up! Bottom line: For the standard portion, use anywhere from 2 to 4 tablespoons of oil. For those doing 1.5 portions, aim for between 3 and 5 tablespoons.

Q. For fruits, you say 1 cup or 1 piece. But what about small fruits like kiwi?

A. For fruits that are especially small, eat two. Imagine cutting that fruit up. Would it equal a cup? If not, add another piece (or half of a piece).

Q. What are the portion sizes for packaged bread and tortillas?

A. Even though the grain portion on Phase 3 is half that of Phase 1 (i.e., 1/2 cup wild rice compared to 1 cup on Phase 1), the standard portions for packaged items on Phase 1 and Phase 3 are the same. Otherwise, we’d get into a situation where the portion size was 3/8 of a tortilla. That’s just too weird. So for both Phase 1 and 3:

  • 1 slice of phase-appropriate bread
  • 1 8-inch phase-appropriate tortilla
  • 1/2 of a phase-appropriate bagel