Disclaimer: This blog post is my opinion. As with all of my diet reviews, the purpose of it is to examine the claims that the diet makes against the laws of physiology as well as the latest research. 

I’ve had a few requests to review the Fast Metabolism Diet, and once I took a two second look at the website, I immediately knew that I had found my next Diet Review. Hey, the author of the diet calls herself ‘The Metabolism Whisperer’! Can she actually coax unruly metabolisms into submission?  I needed to see this, most definitely. This review applies not only to this particular diet, but to most ‘metabolism diets’.

(Read my review of the Metabolic Renewal program here)

What is the Fast Metabolism Diet?

At first glimpse of the website, it’s apparent that the Fast Metabolism Diet is only a small part of what’s essentially a library of diet books by the same author. Not only that, but there’s a supermarket-sized offering of Metabolism branded pills, bars, shakes, audio books, digital books, apps, baking mixes, Metabolism spinach fettuccini noodles ($35.00 for a 12-pack..get ‘em while they last), and basically anything else you could want.

I’m sort of shocked that I couldn’t find a snow brush for my car or a couple of throw pillows on there as well. Maybe those are coming soon! 

Anyhow, I know that for many people, metabolism seems complicated. It’s actually not all that bad once you have the details broken down for you, and when you do, you’ll figure out that diets like this one that claim to speed up metabolism, are largely garbage.

Yes, I’m going there. Is it too early to make that statement?

Here’s the basics of what you should understand about metabolism:

  • Your metabolism is essentially how your body turns what you eat and drink into energy.
  • The only thing that we know of that really speeds up metabolism for the long-term is exercise. The more lean body mass (otherwise known as muscle) you have, the more calories you’ll burn at rest (aka increased BMR). 
  • Things that affect metabolism speed include: genetics, age, muscle mass, medications, caloric intake, hormones (especially thyroid hormones), body size, sleep patterns, and possibly gut bacteria. Diets – especially really low calorie ones – slow metabolism to conserve energy – it’s an adaptive measure that we’re born with so we don’t starve to death. 
  • I wrote an in-depth post about metabolism here. You can read it for more information about how your metabolism works (and doesn’t work), especially in relation to weight. 

The Claims of the Fast Metabolism Diet

When someone comes along and touts a ‘metabolism changing’ diet with detoxes, cleanses, and a boatload of metabolism-boosting supplement$, I immediately smell BS. When she writes 4+ books on the same subject, I wonder why the first one wasn’t effective enough that she needed to write three more.

When that person also poses on her website wearing a lab coat (for no apparent reason, but lab coats say you mean business, right?), and has been known to promote crazy unsubstantiated-by-science things like ‘fat burning foods’, I need to raise an eyebrow.

When I find that she has a degree in agricultural and animal science and then some education in homeopathy aka pseudoscience, I start nodding my head as in, ‘ahhh, I get this now’. But wait! She’s Hollywood’s ‘top nutrition guru’, which says a lot. Or wait. Hm. 

I know that I should keep an open mind to other healthcare disciplines, and I am sure that the author has helped many people in her own way. But seeing someone promoting patently false and overreaching claims and using them to sell all sorts of useless but expensive stuff makes me upset. I feel like vulnerable people are being taken advantage of, and that’s not okay. 

The Fast Metabolism Diet tells us that “food is not the enemy but rather the medicine and the fuel needed to rev-up our sluggish, broken-down metabolisms and turn our bodies into fat-burning machines.” 

And my favorite, “this is the silver bullet for anyone who wants to naturally and safely eat their way to a skinnier, healthier self.”

Translation: this is a fast, effortless way to eat and be skinny, which automatically means healthy. It’s all natural, except for the piles of supplements you need to consume on this plan (but I digress…more on that later).

And can we please refrain from ever using the word ‘skinny’ as if it’s some sort of desirable way of being? 

The Fast Metabolism Program

The Fast Metabolism Diet is a 28-day plan that has a rotation of three phases. Basically, the author claims that eating the right foods at the right time can ‘trick’ your metabolism into speeding up.

In her own words, “Each Phase focuses on different whole, healthy foods to calm your adrenal glands, reduce stress on your liver, and feed your thyroid so it can produce the hormones T3 and T4, the superstars of a fast metabolism.

You’ll reduce stress, too—and as a result, put the damper on the belly-fat hormone, cortisol. By keeping your metabolism guessing, you’ll get it working faster.”

Hint: your metabolism doesn’t ‘guess’ anything. Stop personifying bodily functions.


There are a lot of rules on The Fast Metabolism Diet. Here they are:

1. You must eat five times per day

2. You must eat every three to four hours except when sleeping

3. you must eat within 30 minutes of waking

4. You must stay on the plan for the full 28 days (keep repeating if needed until you reach your      target weight, then repeat either full 4 weeks every 6 months or 1 week every month)

5. You must stick to the foods allowed in the phase

6. You must follow the phases in order

7. You must drink half your body weight in ounces of water every day

8. Eat organic whenever possible

9. Meats must be nitrate-free

10. Exercise according to your phase

11. No wheat (excepting sprouted or natural yeast wheat)

12. No corn

13. No dairy

14. No soy

15. No refined sugar

16. No caffeine (or alcohol)

17. No dried fruit or fruit juices

18. No artificial sweeteners or fat-free diet foods

Keep in mind that after the 28 days, she recommends that you continue to avoid corn, soy, sugar, and caffeine except for ‘special occasions’

The phases and their ‘rules’ are as follows:

Phase 1: ‘Unwind’ days 1-2: 

This phase consists on high-glycemic, moderate protein, and low fat foods to ‘calm the adrenals’. I’ve never seen a diet that encourages high-glycemic foods as a rule, but alright then.

No nuts are allowed in this phase. ALL FATS are to be avoided. 

Phase 2: ‘Unlock’ days 3-4:

This phase is supposed to ‘unlock stored fat’ and build muscle. 

It allows only high protein, low carb, and low fat foods. It’s basically proteins and ‘alkalizing’ vegetables, but not no beets, carrots, peas, pumpkin, sprouts, sweet potatoes, tomatoes, turnips, squash or zucchini. What the eff did zucchini ever do to anyone? You’re also not allowed any grains or fruit.

No nuts are allowed on this phase.

Phase 3: ‘Unleash’ days 5-7:

In this phase, your metabolism is supposed to come roaring out of hibernation to burn all your fat! Exciting!! This phase is high in healthy fats, moderate carbs and proteins, and allows only low-glycemic fruit. It also includes ‘Thyroid-stimulating foods such as seaweed, coconut oil, shrimp, and lobster’

The portion sizes of food vary by phase and by amount of weight you want to lose. 

Let me put this out there RIGHT NOW because I’m already tired of this BS: 


Nowhere in the world is there research that tells us it’s beneficial to ‘surprise’ our metabolism and ‘keep it guessing’. Your metabolism does NOT work like that. It doesn’t have a brain, it doesn’t like playing games, it doesn’t guess anything. 

The only thing your thyroid needs to be ‘fed’ is iodine. If you live in a first-world country and have a varied diet, it’s unlikely that you’re iodine deficient. Also: coconut oil doesn’t stimulate your thyroid any more than Big Macs do. 

How can being on a diet ‘reduce stress’? Think about that for a second, will you?

T3 and T4 are thyroid hormones, as outlined in my Learning Curve post about your thyroid (here). There is no reason to take thyroid hormones or worry about them unless you’ve been diagnosed with a thyroid issue.

Also, the T3/T4 combination that many alternative healthcare practitioners sell (it’s available as part of this diet too, $HOCKER) has not been proven to be more effective than the T3 that is prescribed by physicians.

Supplements are not as tightly regulated as actual medications, so it’s anyone’s guess if what you’re buying is actually as effective as it claims. If you’re messing with your thyroid, don’t do it with some random ‘natural’ pills you found on the internet. That can cause you a world of trouble. 

There are no foods that can speed up your metabolism enough to burn fat. The thermic effect of food exists, yes – but the amount of calories you burn while digesting a chicken breast or a mouthful of chili peppers doesn’t make you lose weight.

There are no fat-burning foods. You can’t switch your metabolism off and on and off and on like a light.

You are okay. You’re going to be okay, without the Fast Metabolism Diet, so don’t go there. And if you do, the reason why you’re losing weight probably has nothing to do with your metabolism. It’s because you’re so restricted with what and how much you can eat. 

I would be remiss if I didn’t bring up the fact that soy is a big ‘no no’ on this diet, but then the author recommends that vegans following the diet eat tempeh and tofu…pure soy. Nonsensical.

Oh, and no wheat – but you can have spelt. Spelt actually is wheat. Hello?! I think she’s going for inclu$ivity here…cutting out vegans from this diet means less money for her, so she’s going to bend the rules for them. Nice! 

This is a low calorie diet that forces you to cut out a lot of foods. I mean, if you can’t eat corn and soy, you’re basically cutting out every single ultra-processed food. But instead of admitting that this is why you’re actually losing weight, the author has to lead you down the garden path using her crazy ‘metabolism’ claims.

Sadly, I read several variations on the following in some of the reviews: “The facts and science seem sound, although I have not researched them to be sure they are accurate, they make a lot of sense.”

NOOOOOOOO!! No they don’t! But what does make sense is why the diet industry still exists when people don’t do more research about what diets they’re using. 

The Upsells:

I know I just spilled the entire can of beans about the diet, but I still want to talk about the upsells – because the Fast Metabolism Diet seems to win the upsell award and to be honest, I feel that this destroys the diet’s credibility even further.

As I mentioned before, The Fast Metabolism Diet has a veritable smorgasbord of cleanses (lose 5 pounds in 5 days…their words, not mine) and supplements, paid support groups, pre-fab programs that promise to shed pounds in ridiculously short amounts of time with shakes and pills, and ‘bundles’ of supplements that promise to work in synergy – like the ‘Bye Bye Belly Fat’ bundle. 


A lot of the supplements offered in the store are based on imaginary conditions (Candida, I’m looking at you), or have little to no evidence behind their components.

Take the ‘Metabolism Control’ supplement, devised to ‘help you take control of your inner body’ (huh?) and decrease appetite. There’s nothing about vitamin B6, vitamin C, and chromium, random amino acids, and 5-HTP that has been proven to do anything significant for appetite reduction. 

The Metabolism Energy supplement (it’s annoying how every single one of her products starts with the word ‘metabolism’, but I digress) states that there’s Nobel Prize-winning research (this) proving that nitric oxide moves more blood and oxygen throughout your body. Okay, fine.

The author extrapolates this research finding for her own benefit, saying “The extra blood flow helps to remove waste products more efficiently out of fat cells to be burned for fuel.” 

Certainly, increased blood flow through the body may speed up some processes, but to carry that so far as to say that it will help you lose weight is completely made up and not evidence-based at all. They’re seriously making people pay $57.00 for 8.5oz of this stuff,  based on a shitty extrapolation that’s straight from the author’s imagination. Crazy.

I couldn’t find one single research study confirming that nitric oxide or arginine helps people lose weight in this manner. I actually did find studies on just arginine and weight, but they were mostly on rats and pigs. Those are not studies that I accept as proof of a similar outcome in humans.

Sorry. The one human study I found was poorly done, small, and short. Nope. 

There’s a pattern I see with all of the offerings in the Fast Metabolism Diet online store. They’re also exorbitantly priced, but it seems as though everything about The Fast Metabolism Diet is a money grab. It follows the the typical script:

  1. Make people feel as though they have more issues than they really do.
  2. Sell them a ‘solution’ using science-y language they don’t understand. 

It’s the MO of almost every diet program out there, and it’s really sad. You completely do not need a ‘Metabolism Colon’ supplement (inset eyeroll here) or probably 99.9% of the stuff in that store. What also irks me is that on every single page of the Fast Metabolism site, there’s a ‘buy now!’ popup, or some sort of product or service being sold. It comes off as completely disingenuous and gross. 

A Dietitian’s Take on the Fast Metabolism Diet

This is a low calorie diet, period. The phases don’t make any physiological sense, and the elimination of caffeine, wheat, soy, corn, and everything else for the short and long term doesn’t fix anything. It just makes more junk food off limits, and life a lot more annoying and less fun. No thanks.

The author of this diet is a proponent of homeopathy, otherwise known as ‘the air guitar of medicine’.

This does not mean that nothing she says is credible, but it does explain in part why this diet is essentially based on far-fetched and unproven claims. Take responsibility to research diets before you start them. I guess that’s why you’re here, though. Good job!

Working as a nutritionist in Hollywood doesn’t earn you any points. Everybody knows that stars do crazy diets that aren’t credible or applicable to your real life.

There are a lot of money grabs that you shouldn’t fall for. You don’t need to cleanse or detox your body AT ALL. EVER. Why am I still trying to defend this concept? Also, losing weight shouldn’t cost a ton of money. Stop!!

I don’t think this diet is dangerous in any physical way, but why would you ever throw money at something like this?

Hard pass.


  1. Abby, Thank you for this great review! Well said! Thank you for all your hard work researching and writing about this fad diet. There is no magic bullet people! Carol Fenwick Registered Dietitian Nutritionist, Certified Exercise Physiologist, American College of Sports Medicine

    1. Horrible review. I actually read the entire book and followed the diet 4 times with a week in between, minus the coffee part the last two and lost 73 lbs. Like any dietitian, she has some of her own opinions on how certain things work, but the diet definitely works, you will lose weight.

      Also, nowhere does it require any supplements or any of her products to be used for the diet to work. I used none of them.

      The key is a calorie deficit, eating healthy and clean, and mixing the plans helped. I could see phase 2 really dripped the lbs.

    2. I actually did the diet and not just read the book. I had a great deal of success and lost lost 15 pounds in the 28 days. I continued to eat a sensible diet and stayed away from sugars and gluten’s and lost another 13 pounds the following month. I did not use the authors supplements or recipes at all. I read the original book and stuck with it. The first week is tough, the second week I felt much better, slept better and had more energy. It changed my lifestyle and also reduced my blood pressure, cholesterol and triglycerides . I guess my body is to stupid to know it is a low calorie fade diet.

  2. Did you do the diet or just read it? This diet was recommended by a friend who in the 28 days lost 16 pounds. I exersice on a regular basis and fairly health but could not lose a single pound. I have also struggled for a long time with sugar and food addictions. A friend and I decided to give this diet a try, what could I lose other weight? I am amazed at how I feel and how healthy I have been eating! Most importantly my cravings for sugar and candy/cookies/cake/ice cream etc. have almost disappeared. AND I’m losing weight. I’m never hungry, I drinking lots of water and eating good for my body food. Best of all this is a way of eating that I can stick with. I have not taken any of her supplements nor did my friend who successfully lost weight. She continues to eat in a healthy way and has lost 20 pounds so far. I know the diet sound like a gimmick but it has worked for me and two of my girlfriends. Don’t knock it until you try it! 😉

  3. There has never been a diet that has caused me MORE stress than the Fast Metabolism Diet. Not only does what you can eat change by the day, but what you have to measure EVERYTHING. To go away for 3 days, I spent 4 hours in the kitchen prepping, cutting, and measuring food, writing out a per meal list of what needed to be eaten, and labeling each container. Then I had to pack a rolling cooler to bring with me. Throughout my conference, I was watching the clock for when I had to eat, it was unreal. It’s completely over the top, but omg is there a CULT of people defending it. When I bring up problems such as “are we supposed to eat 3 hours from when we start eating, or from when we finish, because the book doesn’t specify” (and that makes a big difference on days when you have to eat an unreasonable amount of food in one sitting, so it’s a pretty big detail to leave out), I get 3 different answers, and then the ever popular “Check out the website, a lot of her rules have changed since the book was printed.” Plus, serving sizes for the various recipes are not included in the book. What the eff?

    1. Couldn’t agree more..FMD caused me so much stress. The food mentioned in the cookbook looks good but so horrible in taste. I did lose weight(around 10 lbs) but all I was thinking about for 28 days was food!! Phase 2 recipes are so bad that I had to gulp them down with water. I am a vegetarian who eats egg..but how much egg whites can you possibly eat !!

  4. I breezed through your review out of curiosity. I agree with the idea of it’s another way to spend money, but I’ve done/am doing this diet and my results are weight loss and (this was my biggest surprise) normal blood pressure for the first time in over 10 years. Regular cardio exercise didn’t help. I refuse to take medication for high blood pressure, even though it’s prevalent in my family. Now I don’t have to. After I’m done with the diet, I will use the maintenance diet. The books are available at the library and the only money I have spent on her products is I downloaded the app for $2.99 to help me keep track of what and when when I’m working.

  5. Thank you for your review. I started reading her book and looked into the phases. Then decided to throw in the towel. I have to cut out certain food and of course she had certain things that you need to buy. coconut vinegar is one of them.

    Well back to the drawing board.

  6. I simply LOVE what you do!!! Every time I fall for these diets and fads i look at your website and I laugh at myself because I’m one of those people. What do you recommend? My fitness pal just to jot it your calories?, calories in and out? seems like everything I read is not going to be successful. I am 20 lbs overweight. And work out. Thanks

  7. Thank you for your review on this diet. I had a friend that recommended it, but said she was on it for just a couple of weeks. Your review was easy to understand and made sense to me.

  8. Interesting perspective. FMD works for me: keeps me away from processed sugar (typically a candy junkie); I like the foods “allowed” during each of the phases (HUGE fruit/meat-eater!); and, it’s not so much the weight loss but the noticeable body changes. This is my 3rd time around in ~10 years. If I would not go overboard on the sugar and ice cream I probably would not need to be on this “meal plan” again. 🙂
    I bought the original book years ago. I created my own color-coded food lists from it (phase 1-2-3) which simplifies the phases and shopping. I don’t buy any of the products because you can follow the plan with regular food, albeit usually more expensive in the grocery stores.
    One of the author’s big points is to remove processed sugar and flour (not wheat) from the user’s diet. It’s pretty well-known that a large percentage of American’s consume way too much of both, to the detriment of their health.
    What I did discover was that I now consume a lot of the same foods my lifetime hockey-playing friend eats as part of his normal/natural eating habits. And he’s a “machine!” In his mid-50’s, he’s healthy, energy of a 20-something (ok… maybe 30-something), muscular, and lean.

  9. I. LOVE. YOU.
    You are hilarious and this is so smart. I’m going to be reading your Learning Curve articles and following your site. Thanks for smacking some sense into me this morning.

  10. Thanks for the review, my friend recommended it for weight loss but did not give any specifics re. success rates.

    I’ll try weight watchers? or maybe just eat vegetables, fruit and lean meat.

  11. Thank you Abby! A coworker at a health club recommended this diet. She is super fit and lost 20 pounds on it – I was shocked! Your blog explains this fad diet in a simple, no nonsense, comical way That makes complete sense to me.

  12. Amen! How can Hailey promote a program supposedly based on healthy foods and NO sugar in any form and only plain water and yet her latest energy drink supplement contains sugar (dried cane syrup) and yes, you can use it in place of plain water if you buy her $50+ canister of 8 ounces of product. Incomprehensible ate these inconsistencies that are amassing incredible wealth for someone with no medical degrees at all! Charging folks to access her Facebook group seems to be simple greed. She admits the average weight loss is a pound and a half a week–but IF you buy her products……….yeah right!

  13. Did you read the basic book, “The High Metabolism Diet?” The 28-day diet requires NO supplements (though a multi-vitamin and or ANY of the products they sell or even visiting the website at all. (To me that’s too confusing anyway.) It is based totally on just food (not processed or “junk” food”) you can buy in the grocery store. You aren’t ever allowed to go hungry (D.I.E.T.=Did I Eat Today?), but to enjoy food. The recipes are of such variety, it’s not hard to find foods you already like. Families often like the food you’re eating, so you don’t have to prepare a separate menu for yourself. You do have to actually cook (prepare food), but recipes are large enough to allow for freezing portions for future days on the diet. I noticed recently on page 30, she talks about a client who in 14 days ate a lot of food, lost 14 pounds, and her doctor took her off her cholesterol medication. When I first did this diet, I happened to be scheduled to have my cholesterol checked (via fasting blood test) when I had just finished 14 days of the diet. All my “numbers” were wonderful, for the first time I can remember. I had not been been on medication because of its side-effects with me. I was shocked (but thrilled), and credited it to the way I had been eating the previous 14 days.

  14. This was an interesting review… although very few of the facts that you refute from the author are backed up by what you call actual science. Why isn’t it good to keep your metabolism guessing? Has there been actual tests done on this diet to actually discover if this is an effect method for weight loss? Why would eliminating caffeine, soy and corn not do anything longterm? I am interested in trying this diet. I will keep you updated on my results. I have to say that I am extremely offended by your interpretation of homeopathy. I have been using it to work on my depression and had outstanding results. I didn’t have to go on anti-depressants. My naturopath has reversed several allergies as well.

    1. Hey Abby I just wanted to say I’m skeptical about this article too… Especially because I tried the diet a couple years ago and had weight loss results literally within the first week. And I personally think it’s good to eliminate sugar, dairy, corn, and gluten. There’s tons of evidence that backs up the fact that these foods are bad for us and our digestion.

      1. Hi Mackenzie, thank you for your comment! I’d like to see some of the evidence that you believe proves that dairy, corn, and gluten are bad for us and our digestion.

        1. Oh, YOU’re a researcher…just look around a bit. It’s out there. Even if I agree with some of yourobservations, you have the smug tone of a “sciency” person. Science is wrong on a regular basis, so…I rely on common sense and what seems to work for the most people. People are smarter than you think, and a medical degree does not guarantee sound nutritional knowledge.
          The ” I’m a skeptic and that makes me the harbinger of truth” attitude is kind of a turn-off. How about some proof that corn, wheat, etc IS good for everyone?

          1. She is a Registered Dietitian as am I and we are nutrition experts. We make recommendations based on science because that’s what 4-6 years of school trains us to do. Studies are ongoing in all areas of nutrition and recommendations change as new information is validated from more than one study. I came across this site because I have a patient who wants to discuss metabolic confusion-which isn’t a validated theory either. The “research” you say is out there is nothing more than testimonials and half assed explanations that sound good to someone desperate to lose weight. I tell people anyone can write a book or start a blog but it doesn’t make them an expert. The diet industry is a multi billion dollar industry for a reason…most of it is BS.

          2. Amen to you!!! I have Hashimoto and when I stop eating GMO, soy, corn, dairy, legumes and gluten not only I felt healthier, energized and my thyroid numbers improved also. Recently, when I had some of those in my diet, I felt heavy, constipated, gained weight.. I am going to try this diet and see what happens.

        2. I am going to research this a bit more. The claims of this diet are interesting and I cannot disregard them just because the author has made a successful career out of this plan. Some leads that I have that may help to explain the roles of these foods in health and disease are:

          – Gluten is known to activate zonulin in enterocytes and promote intestinal hyperpermeability (by means of loosening gap junctions) in individuals with and without celiac disease. In the event proteins are not broken into 2-3 amino acid lengths (which happens commonly for a variety of reasons), can stimulate adaptive immune cells into (a) delayed-type food sensitivity and (b) autoimmune condition (important link since the leading cause of hypothyroidism in the US is autoimmune Hashimoto thyroiditis)
          – It is know that the glycoprotein structure has a role in cardiovascular and autoimmune disease, as well as cancer. What is the role of the glycoproteins structures within gliadin and the various glycoproteins in dairy products with regard to these health conditions.
          – There is strong link between unmoderated intake of starch containing foods, such as corn and wheat, with regard to insulin sensitivity. In turn, I have seen those with reactive hypoglycemia and develop abnormal cortisol rhythms, correlated with blood sugar peaks and valleys (likely cortisol spiking to stimulate gluconeogenesis). In this case, there is a potential link between higher stress hormones and higher intake of refined sugars and starch.
          – This may account, as well, for the suggestion regarding meal timing while awake.
          – Also, along this same line I am reminded of the relation of the circadian rhythm to stress hormones and the diurnal variation of other glands in the endocrine system. It may be fruitful to further study if thyroid function is impacted by (a) cortisol, (b) glycemic control and (c) circadian rhythm. My guess is yes, though I am not sure all of this nuance will be captured in a single study… maybe a string of studies or a good textbook in physiology.

          Let the research continue!

          My personal investment is in part due to my success with the diet and in part my agreement with many points you’ve made in your review. I did not undertake the diet to lose weight but to see how it works for hormonal balance. I already ate a diet close to Whole 30 before beginning and regularly did intermittent fasting. I exercise cardio and strength training multiple times per week. 2 weeks into the diet, I have lost 12 lbs… very interesting. I do not take any of the suggested supplements… just me. I will be retesting TSH, free T3 and free T4 once complete just to see… keep you all posted.

  15. I did this diet for the first phase and I had a constant headache for three days because of the no caffeine. I constantly thought about food because of how strict this diet is. And it’s EXPENSIVE!!! Also the sprouted grain bread gave me diarrhea. Never again. I’ll stay on my regular eating healthy and exercise.

  16. I actually lived this diet for about a year. When I began this lifestyle of eating I was about 20 lbs overweight; so the adventure began, meal planning and prepping with my husband who is perpetually thin. To keep the weight on him I made sure he had grains at every meal. The fun part was that we prepped together every Saturday. After 28 days I did indeed lose the 20 lbs and a bit more and kept it off the entire year. Then I had a skiing accident and my husband did not continue prepping alone. I gained the weight back plus some. this is a lifestyle, not just a diet. And it does lead to a healthier medical life and can aid an active lifestyle. You would have to be someone who struggles to lose weight and keep it off to understand the truth is in the pudding no matter the lingo that this author chose to use. Oh, and I do have thyroid issues and currently take thyroid medication, it is true it does not change the thyroid output, but it does help considerably the amount of exercise output I need to begin to lose weight, and to keep weight off.

  17. I appreciate this article Abby but I also have tried the diet. I struggled with weight loss for several years. I ended up losing over 40 pounds on this diet…no supplements, or shakes just food. I also had the best numbers (blood pressure, heart rate) I’ve had in my adult life. I’m not a doctor and I respect your opinion but I can’t deny the results.

  18. Open and honest reviews – what an oddity! I appreciate your addressing the pro’s and con’s as directly as you did. I am not an expert, nutritionist, doctor or anyone who can claim to provide any technical data or scientific evidence but I can talk about my personal experience.

    My wife had done some research into this diet and wanted to try it. Being the smart husband I am, I said “OK”. Our close friend is a nutrition enthusiast and said no diet will work because once you’re done, you go back to unhealthy habits. My wife was going to try it and I was going to support her (I think support is better when you do not totally believe in what you’re doing). For information, I was 67 years old, am 6’2″, was 230 lbs and spent (still spend) a great deal of time sitting in front of a computer.

    So we started. The first thing I noticed was that my wife was spending much more time in the kitchen, mostly doing the prep work, not as much actual cooking. Breakfast, snack, lunch, snack and dinner – a lot of time! I had horrible eating habits, typically having coffee for breakfast, stopping for lunch maybe once per week and then devouring anything on the table or in the refrigerator when I got home. Now that I work mostly from home I have much more available time during the day so was able to adapt to the meal/snack schedule. There was a great deal to eat but also some things, like coffee, bread, alcohol and sugar we had to delete for the entire 28 day period. The other change for me was drinking much more water than ever – I said I had bad habits, not drinking al ot of water was one of them. So, we were able to change our habits and committed to do so. Here is a summary of the outcomes after 28 days:
    I am now 68 (just adding this to lighten things up), still 6’2″, sit a lot at the computer – and weigh 214 lbs.
    Did the diet work and will I stay on it? I don’t know if was the diet itself or the fact that I cut out alcohol, bread and sugar but I know for sure I a lost 16 lbs. in a month. Good, right? Well, taking our friends comments seriously, I believe that we have made an “eating lifestyle” change that will include some but not all of what we learned this past month. I believe that we are eating better every day, both in quantity and in quality and will continue being better at eating/nutrition than ever before and I believe THIS IS THE REAL BENEFIT OF GOING THROUGH THIS PROGRAM! I plan on using it as input, as a guide and as an educational reference as I move ahead in my goal of reaching 200lbs. Not looking to link it to a calendar and do it in the next 28 days but hope to see a downward trend in my weight and an upward trend in my ability to enjoy – and participate in what this world offers.

  19. Any diet that’s claiming you will loose all that weight in 28 days is bs…. water weight is easy off and easy on…. stop eating junk…. work out and be consistent…. any diet without caffeine is a no no for me either way….
    thank you for the honest reviews because people out there will pay crazy amounts of money for these crazy diets not really seeing that all they’re doing is crash diets that they will gain right back …. everything in moderation people.:::

  20. I found your review very interesting. I’m 47 years old and was at my heaviest weight when I dove into the FMD regimen. I didn’t even lose the 20 lbs in 28 days, but doing the plan I could actually FEEL that my body was different. FMD has completely changed my life. I lost over 47 lbs in 5 months and have never felt better in my entire life. I almost threw in the towel a bunch of times, but I had a couple friends tell me to not look at the scale and stay the course. I slowly added exercise, walking three miles a day with my dog, then hit the gym for 30 minutes of cardio …which I then increased to 60 minutes of cardio, 7 days a week. I then added weight training with a personal trainer once a week – all of this was gradual. I literally have people I have known for years not recognize me when I run into them. With exercise, your body does want to be surprised and wants things to be changed up from time to time, this has been proven. I believe the same is true with how our body’s metabolize the food we eat. The idea of what to eat together is fairly simple. You can make it as complicated or uncomplicated as you want. I haven’t’ purchased any of the “add ons” except for the cookbook, which I use all the time. If you want to change the type of food you eat and you like to eat, FMD might be a god send. I look better at 47 than I did at 27, and I was a skinny rail when I was 27. Don’t knock FMD until you have given it a go.

  21. I have tried the FMD several times and have yet to finish it. Here’s what I think…you will lose weight on it. I lost a few pounds but they were hard fought. The recipes are great and many people will learn a new and healthier way of eating. The process however quickly went from fun to stressful. I’m a busy mom with a full time job and the planning involved with the FMD eventually added an extra level of stress that I didn’t need. On those busy nights when you’ve just finished picking up kids from soccer, swimming, dance, etc my go to meal was protein on a salad. A family favorite that is healthy and takes twenty minutes to throw together. That meal wasn’t allowed on some of the phases of the diet..anyhow, the long and short of it is yes you’ll probably lose weight on the FMD but be ready to dedicate a ton of time figuring out what to eat and when. You’re probably better off using that extra time jumping on the treadmill.

    On another note, Abby I would love your two cents worth on the bye bye belly bundle. Seems like I can buy the individual supplements at Rite-Aid and save a bundle. Do the supplements work?

  22. I LOVED the FMD!! And I’m doing it again with some friends in a couple of weeks. The food was delicious, I learned to love a lot of new things, I lost a good amount of weight with just the food ( I never felt like I had to add her products or supplements.) I learned to fall in love with eating! Good whole, healthy food! And I felt like I was eating a ton. I did it nice and simple, because I’m not a huge cook. So even though I was eating so healthy, my grocery bill was low. I’m SO excited to do it again!!

  23. I have this book and I wish there really were a way to trick the metabolism. As I read I got discouraged when I saw that that the author didn’t know that semolina, spelt, kamut, and duram were all kinds of wheat – realizing I’ve probably fallen for another scam artist selling what I want to hear. But I can understand why people protest that they’ve lost weight on this diet because the recipes are extremely low calorie. A phase 1 day looks like it could be less than 1000 calories. Personally, I’m determined not to go that low because I know I can’t keep that up my whole life and my goal is to find a way to eat that works, not another crash diet for the next yo yo round.

  24. I did 1 week of this diet. it worked, Id ropped some pound. Especially in Phase 2 which is basically Dukan Diet (just a bit mild).
    The problem is that it costs a lot. And I am Italian and i Eat fruit, proteines, vegetables and wholefoods, not packed junk or ready meals. No caffeine: not a problem, actually I had headache for the first few days then stopped. Dairy:even better as I always get bloated etc with milk.
    But yes, it’s two expensive. Organis, in London UK?

    today I had bought through amazon a book by HP, called The Metabolism revolution. Because I like big titles and being tricked.
    Well, Thanks to this article, I cancelled my order, you saved me 22 quid that I can spend on a ton of fresh vegs!

    I think you are genuine, you are not trying to make money out of this blog and yu follow medicine and not BS.
    I loved the article re food and cancer (the BS about alkaline diet) and and the one published when in Italy (I think those artichokes are from Sardinia where I am from).
    So yeah, I am gonna follow you!

  25. Abby you are right on! This is an extremely low calorie low fat diet for 4 days a week and a very extremely low calorie low carb diet for two days a week! I counted maximum 600 calories on the two unlock days. I bought the audio book and though Halley says emphatically not to count calories she conveniently saves the portion control section for much later in th book….after you get the hard sell! I wrote to her about this and here is the response

    The chapter titled “Your Portions”, which begins on page 103 of the FMD book, will certainly help you determine what amount of each food you should be eating during each Phase based on that Phase’s food list. For your convenience, please also find the electronic version of the portions table through the link below:


    Generally, the category each food belongs to can be found in the Master Food List on pages 77-82 of the FMD book, and for your convenience, you will also find the most up-to-date electronic version of the FMD’s Master Food List through the link below:


    Please contact us again if you have more questions, and thank you for being a part of the Haylie Pomroy community!

  26. I’ve tried several diets including being referred to a dietitian at a weight management clinic at the hospital for 6 mths. She helped me plan out a 1200-1400 calorie a day eating plan. I lost very few pounds despite faithfully entering everything I ate into myfitnesspal. I watched all my macros and counted steps. I had a fatty liver, was prediabetic on metformin, plaque building up in my arteries, migraines etc. My sister told me about The Fast Metabolism diet. I read the book and thought it sounded crazy to eliminate 7 things including caffeine and an entire food group (dairy). I thought for 28 days I’ll try it. Well, its the only thing that has worked for me! I’ve lost 43 lbs and am no longer at risk for diabetes, no meds needed, no migraines or hot flashes. I have never bought any of her products. I can’t explain it, it doesn’t seem right when first reading the book but it works. There is a facebook group that you can follow that is independent of Pomroys site. PS I think her wearing the white lab coat is a little much too along with the cruises you can join her on but the diet itself works!

  27. I followed the Fast Metabolism plan and lost 60 lbs, kept it off two years. The plan has you eating No processed foods. You don’t have to buy anything from Hayley Pomroy. My degree was in nutrition, a long time ago. I do believe the micronutrients affect your hormones and therefore your metabolism. This diet worked for me, but after two years I did fall off plan for several months and gained back some of the weight. I’m starting again on a modified version of F M D.

  28. Abby,
    Totally agrees that the enterprise of FMD products is just crazy- but I haven’t bought any of that junk. There are far too many books and it is a marketing thu g but I swear by the original and the companion cookbook as very helpful to me when. I thing else has been. I don’t see it as a magic bullet but as a guide to cooking and eating – in conjunction with excercise- as a good plan to help me fight off 45+ yr old weight gain.
    A friend told me about her success and I tried the 28 day plan. Amazing success and I try to live this way now, drinking lots of water , eating clean and snacking between meals – all
    with moderation. I still live – and eat pizza and drink wine and beer – but choose my spots.
    My weight and medical labs have not been better. I see an endocrinologist for Hashimotos disease and she concurs that what I am doing is working. I still take meds. but my overall numbers have improved dramatically using the fmd ideas as a lifestyle- not as a fad diet. I see it a s a way of eating – and there are many tasty recipes that are now regularly in our family rotation. I guess this original book and the other cookbook which I bought – have helped me change the way I cook. Batch cooking and having meals Prepped and frozen in advance has been key for my success.

  29. I was contemplating trying FMD again and I found your sobering article. THANK YOU.
    I have tried this diet for short periods 3 times. The self-congratulatory tone of the book and the author’s inconsistencies drove me crazy from the get-go. The main online support group moderators are cultish and food-shaming. I was actually kicked off for saying that it still worked for me even thought I drank coffee. And the mind-numbing number of products and different diets that Hayley Pomroy now is peddling and promoting in my opinion? She should be ashamed of herself.
    That said, this diet does work when nothing else does (for me.) But to other’s points, you are constantly shopping and prepping and it gets quite expensive. But for me the main drawback is it’s not sustainable if you actually want to have any sort of a social life. While life is better when you are happier with your body and feeling good and mostly eating healthy, it’s too short to not drink wine or go out to dinner with your friends or cook spaghetti and meatballs for your family on the weekend. No matter what the FMD converts say, there is NO wiggle room for any flexibility on this diet. And like any diet, when you go off, you gain it back and those pounds generally bring some friends with them. Even though I am getting married this year, I think I am going to break the dieting cycle. Happy I found your site.

  30. Obviously, you have never educated yourself on homeopathy to make such an ignorant comment about how it’s psuedo science. I have been treating my family for 3 years on homeopathy and have a ton of success stories to show that it works. Just hope that you didn’t turn people off with your homeopathy comment that could have used it to cure themselves.

  31. A friend of mine highly recommended this and even bought me the book. Instead of reading it, I downloaded it from Audible and it sounded like a whole lot of gobbelty-gook to me. Still, my friend swore by it (even though a year later she gained back all of her weight plus some, blaming it on family problems). It’s basically a glucose and dairy-free diet. The only glucose allowed is sprouted grain breads. Anybody can lose weight if all they eat are vegetables and lean meat (although potatoes and corn are allowed). Because it is exceedingly restrictive, I will not even attempt it. I had lost five pounds the month my friend recommended this to me by eating less (without excluding any food group) and exercising more. Even that is hard to do on a daily basis, much less stressing over every single meal you ever eat. Great review.

  32. Abby I do think the review was a bit harsh but I get all that you are saying. I think for me the weight loss I experienced both times (first time was way better than this time) was good for me and has helped over all. I am celiac so staying off the grains is fine and I substituted with gluten-free options but immediately noticed that part of my weight issues related to inflammation from eating crappy processed foods and dairy. So it was apparent right away I am just better off dairy.

    As far as the prep it is absolutely more expensive and very time consuming but it helped me with my food cravings because I was getting solid nutritional food that I wasn’t as good at before. I was so busy trying to stay “on schedule” with my eating times I never needed junk in between. This has helped me revert back to eating healthy because from doing keto for a while. Keto totally messed me up as to what is good for me and what is bad and I don`t agree with Keto long term anyway and it is deceiving and not very healthy. Eat the wrong fruit and weight comes right back on… its insane. I missed fruit and it was nice to have fresh fruit as a normal thing to eat on FMD.
    The FMD has turned my eating around and I am thankful for that, so yes the mystery is not in the metabolism whisperer exactly, but more about eating clean consistently to what our bodies need anyway. Its important to not starve yourself then binge because you could eat the entire fridge from crazy low everything bad dieting that lacks all food worthwhile and actually healthy. These make you crave everything from sugar to salty and as much ice cream as in Baskin Robbins!
    I am happy I have found a balance and hope I can maintain eating healthy without the scheduled 3 hour eating and bulk store-sized prep needed. I plan to be more conscientious and I think that and moderation are the keys.
    I will check out the learning curve articles you mention.
    Thanx for the honesty!

  33. When you make comments such as “the author of this diet is a proponent of homeopathy, otherwise known as ‘the air guitar of medicine’, you have lost the reader’s trust and respect. It’s okay to disagree with the Fast Metabolism Diet, but to go as low as to trash Halie Pomroy with your comments is just not professional! Who cares she wears a white lab coat in her videos and has a website selling supplement. FYI… People don’t have to buy supplements to do the FMD.
    YES, you should absolutely keep an open mind to other healthcare disciplines because every professional has their own way to help people get healthy to lose weight. Disturbing review for sure!

  34. Dear Abby, thank you very much for the time you spent to comment on this diet!!!! I nearly bought it ?. As a 56 year old woman with a history of dieting I should know…. The only thing that worked for me ever was a decent workout and eliminating processed food. And I knew that the stress I’m going through since the last three years made me sleep bad, eat OK but with a lot of coffee and no workout at all. And the result is what I’m looking at now. And I also know that if I beat up on me bc of that, I’m not going anywhere near feeling OK with me.
    You are absolutely right about anything. Thank you for reminding me that I’m OK and that I just need more time for myself and eliminate the things that don’t work out for me in my life (including people who make me feel bad bc I work my ass of and I’m overweight).
    Keep going!!!
    Greetings from Germany

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