What Is the Fast Metabolism Diet? (2023)

The Fast Metabolism Diet claims to rev up your metabolism so that you can eat plenty of food and still lose weight. The diet's inventor, Haylie Pomroy, suggests that you can eat three full meals a day plus two snacks and lose up to 20 pounds in 28 days.

Your dietary goals are accomplished by rotating foods throughout the week. This, according to Pomroy, who is also a nutritionist, will speed up your metabolism so that you burn more calories and lose weight.

The Fast Metabolism Diet does not require you to count fat or carbs or track your calories. It does, however, require you to stick with the allowed foods on the plan and to strictly avoid other foods, which may pose a challenge since some of the foods that aren't allowed are common in the standard American diet (wheat and dairy products among them).

The Fast Metabolism Diet allows plenty of healthy fruits, vegetables, lean meats, and whole grains, which is a point in its favor. However, you're only allowed to eat certain things on certain days, which may be problematic for meal planning purposes. The premise of this diet—that it's possible to make your body's metabolism run faster by eating only certain foods in a particular order—does not have any medical studies to back it up.

Pomroy, a regular on NBC's "Extra" and "Access Hollywood," has worked with celebrities ranging from Cher to Robert Downey Jr. on weight loss and nutritional goals. She calls herself "the metabolism whisperer" for her focus on how the body burns calories and uses nutrients obtained through food.

According to Pomroy, diets, low-nutrient foods, and too much stress can slow down your metabolism, and weight gain is the result. The diet blueprint outlined in her bestselling book goes into detail on various hormonal effects of weight gain, plus the impact on your liver, your muscles, and your different types of fat.

The Fast Metabolism Diet might suit people who are seeking weight loss but who are also willing to incorporate exercise into their routines and give up entire categories of foods to achieve their goals.

What Can You Eat?

There are six rules that Pomroy says are critical to follow in order to see success with the Fast Metabolism Diet. They involve eliminating five foods that make up the bulk of many people's diets, plus one particularly common ingredient in popular beverages:

• Wheat
• Corn
• Dairy
• Soy
• Refined sugar
• Caffeine

To make the elimination of these dietary staples more manageable, especially caffeine, Pomroy recommends patience—along with adding cinnamon to a morning smoothie and trying feverfew or ginkgo biloba, which may help with caffeine withdrawal headaches. Still, some people may find that giving up their morning latte (neither the caffeine nor the cow's milk is allowed as part of the Fast Metabolism Diet) is a bridge too far.

What You Need to Know

"The Fast Metabolism Diet," first published in 2013, has its roots in Pomroy's work in animal nutrition. In animal husbandry, it's possible to shape the type of meat produced by farm animals (fatty and marbled vs. lean) by manipulating the food the animals eat, which in turn either revs up or turns down their metabolism. Pomroy says she realized humans could achieve the same effect by eating different foods.

"Your metabolism is your body's system for dealing with the energy you take in through food," Pomroy writes. "The metabolism shuttles that energy into different directions according to what you eat and what you do. The beauty of your metabolism is that it can be manipulated because how you eat and move and live affects how much of your food is stored as fat, how much is used as energy, and how much is devoted to building the structure that is your body."

The 3 Phases of the Fast Metabolism Diet

Each phase of this diet plan has its own focus and distinct food lists. According to Pomroy, the phases help your body recover from the previous phase and prepare for the next phase. The phases last for a week altogether, then repeat three times for four weeks in total:

• Phase 1 (days one and two) is to "unwind stress and calm the adrenals."
• Phase 2 (days three and four) is to "unlock stored fat and build muscle."
• Phase 3 (days five, six, and seven) is to "unleash the burn," and focuses on your hormones, heart, and "heat."

The idea, Pomroy says, is to provide your body with the variety it needs in order to obtain all your necessary nutrients. "You need complex carbohydrates, natural sugars, protein, fat, and even salt to maintain normal body chemistry," she says, adding that you may need high levels of these elements, especially if you've been eating a poor diet for a long time.

However, she says, you shouldn't include everything you need at once, which is the idea behind the different phases. Shifting between the phases allows the systems and organs targeted in each phase to rest and restore in turn, she says.

Phase 1: What to Eat

Phase 1 is the high-glycemic, moderate protein, low-fat phase. It includes carbohydrate-rich foods such as brown rice and quinoa, fruits that are high in natural sugars, and low-fat, moderate-protein foods.

Phase 1 includes breakfast, lunch, and dinner, plus snacks. Breakfast consists of grains and fruit, lunch includes a grain, a protein, a vegetable, and a fruit, and dinner features a grain, a vegetable, and a protein. This routine, according to Pomroy, teaches your body to use food as energy instead of storing it as fat.

Exercise in Phase 1 should include at least one day of vigorous cardio. Pomroy recommends running, working out on an elliptical trainer, or an upbeat aerobics class.

Phase 2: What to Eat

Phase 2 is the very high-protein, high-vegetable, low-carbohydrate, and low-fat phase of the Fast Metabolism Diet. It features high-nutrient cruciferous vegetables and lots of lean protein.

Like Phase 1, Phase 2 includes breakfast, lunch, and dinner, plus two snacks. However, the emphasis is on foods that will build muscle, as opposed to relatively high-carb fruits and grains. Breakfast features lean protein and a vegetable, lunch is another protein and vegetable, and dinner is protein and more vegetables. Both snacks are lean protein, such as buffalo jerky or a few slices of deli chicken.

Exercise in Phase 2 includes at least one day of strength training, with a focus on lifting heavy weights with low reps.

Phase 3: What to Eat

Phase 3 is the high healthy-fat, moderate carbohydrate, moderate protein, low-glycemic fruit phase. It includes foods that are high in healthy fats, such as avocados and coconuts, lots of berries, some grains, and little meat.

Phase 3 includes breakfast with fruit, a fat/protein food, a grain, and a vegetable. Lunch features a fat/protein source, a vegetable, and a fruit, and dinner has a fat/protein source, a vegetable, and a grain/starch. Both snacks include a healthy fat plus a vegetable.

Exercise in Phase 3 includes at least one day of stress-reducing activity such as yoga or a massage.

Sample Shopping List

The Fast Metabolism Diet emphasizes healthy fruits, vegetables,lean meats, andwhole grains,but limits consumption of certain food groups depending on which phase of the diet you're in. The following shopping list provides an overview of what you'll need during each phase. Keep in mind this is not a definitive shopping list and you may find other foods that work better for you.

Phase 1

• Brown rice (long grain, short grain, basmati)
• Brown rice pasta (penne, macaroni shells, spaghetti)
• Quinoa (regular and tricolor)
• Oatmeal (steel cut, quick-cooking, rolled oats)
• Mangoes
• Apples (pink lady, granny smith, Honeycrisp)
• Oranges (navel, Cara Cara, mandarin)
• Figs (fresh and/or dried)
• Lean beef (lean cuts of steak and ground sirloin)
• Turkey (turkey breast and ground turkey)
• Lentils (green, red, black)

Phase 2

• Dark leafy greens (kale, collards, mustard greens, Swiss chard)
• Broccoli (florets and whole crowns)
• Cabbage (red and green)
• Onions (red, white, Vidalia)
• Asparagus
• Lean beef
• Buffalo/bison (ground or sirloin tips)
• White meat chicken (whole breasts)
• Low-fat fish (cod, flounder, sole)
• Eggs (whites only)

Phase 3

• Nuts (almonds, walnuts, cashews, pecans, pistachios)
• Seeds (chia, hemp, pumpkin, flax, sunflower)
• Nut butters (peanut, almond, cashew, sunflower)
• Avocados
• Coconuts (whole, half, dried/shredded)
• Olives (green, black, kalamata, castevetrano)
• Salmon (fillet, smoked, canned)
• Berries (blueberries, raspberries, strawberries, blackberries)
• Asparagus (green, white, purple)
• Beans (black, pinto, chickpea, kidney)
• Cauliflower
• Quinoa
• Seaweed (wakame, hijiki, kombu)
• Beef and chicken liver (whole/raw or canned/pate)

Sample Meal Plan

A variety of fruits, vegetables, whole grains, legumes, and healthy fats are encouraged during different phases of the Fast Metabolism Diet. You are advised to consume lean protein likechickenbreast, lean cuts of beef, and low-fat fish. Since it's recommended you restrict your caffeine and sugar intake, it might be best to just drink water with your meals to promote hydration and weight loss.

The following meal plan shows you what a typical day during each of the three phases might look like. Note this plan is not all-inclusive, and if you do choose to follow the diet, there may be other meals that are more appropriate to suit your tastes and preferences.

Phase 1

• Breakfast:1 cup steel-cut oatmeal topped with 1/4 cup chopped apples and figs
• Lunch:Quinoa-stuffed turkey roll-up (sub turkey breast for chicken and omit feta); 1 whole orange
• Dinner:3-ounce grilled sirloin steak; 1/2 cup spiced brown lentils with brown rice

Phase 2

• Breakfast:Eggwhite omelet (3 eggs) stuffed with 1 cup kale, 1/2 cup broccoli, and 1/4 cup onion
• Lunch:Arugula salad topped with 1/2 cup steamed asparagus and 3 ounces of pan-seared cod
• Dinner:1/4 pound bison burger served in a collard green wrap (no bun); 1 cup cabbage slaw (omit dairy)

Phase 3

• Breakfast:12-ounce smoothie blended with 1 cup berries, 1/4 of an avocado, 1/3 cup shredded coconut meat, 1 tablespoon nut butter, 1 teaspoon chia seeds
• Lunch:1 serving of loaded Mediterranean salad with cauliflower tabbouleh (sub olives for feta); 3-ounce fillet grilled or pan-seared salmon
• Dinner:4-ounce serving beef liver and onions; 1/2 cup steamed asparagus; 1/2 cup quinoa

Pros and Cons

As with all diets, the Fast Metabolism Diet has its benefits and drawbacks. Reviewing the pros and cons can help you decide whether this is the right diet plan for your weight loss goals.

Pros

Healthy Foods

The foods included throughout the one-week span of this diet plan certainly are part of an overall healthy diet, which calls for lots of fruits and vegetables, lean protein sources, and whole grains. If you take the week as a whole, there's sufficient variety to keep you from getting bored, plus plenty of variation that should provide you with the vitamins, minerals, and micronutrients your body needs to function.

Exercise

The Fast Metabolism Diet recommends rotating between different forms of exercise: aerobic, strength training, and yoga. This is a recommendation that's supported by research since it keeps your overall level of activity up while allowing specific muscle groups to recover on off days.

Cons

Complicated

Although Pomroy's book is filled with descriptions of how simple the Fast Metabolism Diet is to follow, it's actually somewhat complicated. It can be easy to forget which foods you're supposed to eat (and avoid) on which days. Since the most effective weight loss program is one you'll actually stick with, this one might not be ideal for some people. Pomroy does, however, offer an app that helps in meal planning and in keeping the three phases straight.

Limited Choices

While it's possible to strictly limit your regular food options if you're only planning on doing it for a very limited time, it's probably not sustainable for most people in the long term. In addition, although the diet may help to introduce you to foods you don't normally eat, its regimentation probably won't help you to develop healthy eating habits that you'll stick with.

Is the Fast Metabolism Diet a Healthy Choice for You?

The day-to-day food regimen of the Fast Metabolism Diet lacks balance and fails to meet the healthy diet recommendations outlined by the U.S. Department of Agriculture (USDA).

However, there are research-supported ways to ramp up your metabolism without the need to restrict food choices. If you learn how many calories you need per day, and then boost your physical activity level, it should boost your metabolism as well.

There's also a bit of evidence that low-carb diets, such as the Atkins Diet and the South Beach Diet, may actually help to increase your metabolism. A 2014 study found that people following a low-carb diet lost more weight than people following a low-fat diet. While this study isn't definitive, it does indicate that you might have different choices when it comes to eating plans that potentially increase your metabolism. You also should note, though, that low-carb diets have nutritional issues of their own.

Health Benefits

The Fast Metabolism diet focuses on eating fairly healthy foods and promotes exercise, which is integral to long-term health and weight management. Despite the many positive reviews of the Fast Metabolism Diet, there's no robust medical science behind the idea that this diet plan with its strict regimen will actually increase your metabolism.

Health Risks

While there are no common health risks associated with the Fast Metabolism Diet, the strict rules around the diet are strangely regimented and are not based on science. In general, eliminating healthy food groups is not part of a balanced diet.

A Word From Verywell

Choosing a weight loss program can be confusing. It's easy to buy into the hype surrounding popular diets, especially if the diet in question is presented with celebrity backing plus hundreds of glowing reviews. The Fast Metabolism Diet might help you to lose weight—lots of people report that it works, at least in the short term. But long-term, it won't help you to develop healthy eating habits that will sustain your weight loss beyond that initial effort.

Remember, following a long-term or short-term diet may not be necessary for you and many diets out there simply don’t work, especially long-term. While we do not endorse fad diet trends or unsustainable weight loss methods, we present the facts so you can make an informed decision that works best for your nutritional needs, genetic blueprint, budget, and goals.

If your goal is weight loss, remember that losing weight isn’t necessarily the same as being your healthiest self, and there are many other ways to pursue health. Exercise, sleep, and other lifestyle factors also play a major role in your overall health. The best diet is always the one that is balanced and fits your lifestyle.