It’s easy to get sucked in to fad diets, so read this.

Why Fad Diets Don’t Work

Written by Russ Howe PTI, and most recently updated 1 day ago.

13 min read

Fad diets have been a thing since I was a kid, but in the age of the internet there are more of them than ever before.

Heck, it seems like we all know somebody who’s knee-deep in a four-week banana cleanse, or buying into whatever tomfoolery Gwyneth Paltrow is selling nowadays.

In this article I’m going to explain why fad diets do not work, and why you should steer clear of them if you want to build a great body.

Table of Contents

Why They Don’t Work

why fad diets dont work

The human body is the most sophisticated machine any of us will ever operate.

It’s more advanced than the latest i-Phone, or even the highest-spec PC, so the very notion that we can “trick it” is absurd.

Unfortunately, that’s the shaky foundation which every fad diet is built upon.

Teaching people about proper nutritional strategies and personal accountability seems like too much of a ball-ache for the so-called “experts” who sell these nonsensical diet plans, so instead they’ll spout bullshit about how you can “trick your body into fat burning mode” by eating one type of food (e.g. “the cabbage soup diet”, and “the banana diet”), or they’ll demonize entire food groups and pin all of the blame on a pantomime villain:

  • No carbs!
  • No sugar!
  • No fat!
  • No protein!
  • No gluten!
  • No dairy!
  • No happiness!

This creates numerous problems.

  • It encourages an unhealthy relationship with food

As someone who has spent most of my life around fitness enthusiasts and bodybuilders, I can tell you that labelling foods as good and bad (or clean and dirty) is the first step to an eating disorder. (1, 2, 3)

The same goes for avoiding entire food groups (i.e. calling carbs “the enemy”).

Unless you have underlying health issues (e.g. bad kidneys, diabetes, coeliac) which force you to avoid/regulate your intake of certain nutrients, then there is no bogeyman. Weight loss is governed by caloric input, so it all still comes down to calories in versus calories out. (4, 5)

  • The majority of the weight you lose is just water

Ever noticed how people can drop an impressive amount of weight in the first two weeks, then hit a brick wall where they can’t lose any more weight no matter what?

That’s because most fad diets are built around the idea of reducing/removing carbohydrates from your diet.

Your muscles consist of more than 75% water, and carbohydrates play a key role in regulating this, so when you drop “the c word” from your diet it leads to a brief period where the body is flushing lots of water from the muscle cells, which leads to a reduction of 5-20lbs on the scale. This process lasts about three weeks. (6)

After that you’ll reach a stage where there’s no more water to flush, so it seems like weight loss suddenly grinds to a halt. This can be frustrating as a motherfucker, and to top it off, when the person eats any carbohydrates they re-gain the water weight they had shed, which can make them feel like they’re back at square one. This often triggers a binge our of sheer frustration, and usually leaves the person heavier than when they first started the diet. Fuck that with a capital fist. (7, 8)

  • Fad diets involve huge calorie cuts

If being told to avoid all of your favourite foods isn’t bad enough, you’ll have to do it while staying below an absurd calorie target. These targets are very unsustainable.

Trust me, even the most determined people can only last so long on 600 calories per day!

  • They can cause nutritional deficiencies

As mentioned above, fad diets will usually give you a rigid list of foods which you can eat, and everything else is forbidden. At first this can make the diet seem simple (because if it’s not on the list, you can’t eat it), but it will cause severe damage in the long-term.

Back in the 1800s, sailors would catch scurvy as a result of eating nothing but fish and rice for months at a time. Fad diets essentially do the same thing, because there’s no way of achieving a full spectrum of macronutrients, vitamins, and minerals with such a restrictive diet. Nice teeth, bro! (9)

I’m going to have Dr. Layne Norton, PhD, answer this:

layne norton

“There are two reasons.

1) The stuff that works isn’t sexy. It’s been known for years and it’s not a secret. It’s the same reason people buy into financial scams. They want a quick fix.

2) People don’t like accountability or personal responsibility. If you listen to folks who sell these diets, most of their spiel is trying to convince you that nothing is your fault and there’s a magic fix. That’s very attractive to people who don’t want the ego pain of taking responsibility.”

A List Of Fad Diets To Avoid

why fad diets dont work

Okay, all fad diets are full of shit, but some are more popular than others.

It seems like every time January swings around, I see the same bunch of names popping up on social media, targeting people who want to lose weight. All it takes is a clever celebrity endorsement, or a good social media campaign, and something can become huge overnight.

So here’s the lowdown on why these motherfuckers should be avoided.

fad diets
  • The Dukan Diet

This diet from Dr. Pierre Dukan gained popularity in the 1970s when it was regularly mentioned in celebrity magazines.

It’s a low carb diet which is split into four phases.

During phase one you are instructed to eat only protein. In phase two you’ll eat protein and vegetables. Phase three is for protein, vegetables, and starches, and phase four states that you can eat whatever you want (?!), providing you set aside one day per week as a protein-only day. Oh, and that you “take the stairs whenever possible, darling.”

Why The Dukan Diet Doesn’t Work:

1. No calorie targets. Telling me that I can eat whatever I want “as long as I use the stairs” is horrendous advice, because there aren’t enough stairs in the world for the amount of cake I would eat.
2. Unsustainable long-term.
3. Very restrictive food choices, especially in the early stages.
4. Cutting out entire food groups, so you miss out on key micronutrients.
5. The bulk of weight lost is simply water, due to zero/low carbohydrate intake.

does the hcg diet help you lose weight
  • The HCG Diet

If you thought The Dukan Diet sounded a bit nuts, you ain’t seen nothin’ yet!

The HCG Diet advises people to eat 500-800 calories per day. If you slip up and go over your intake, you are instructed to eat just 6 apples the following day “to make up for your mistake” (you cheating bastard).

Oh, and then there’s the small matter of injecting yourself (yep!) with the pregnancy hormone HCG, because they believe this will speed up the fat burning process.

When it comes to food choices, once again we are encouraged to go low carb.

Why The HCG Diet Doesn’t Work:

1. HCG injections are dangerous. They’ve been shown to cause everything from headaches, to constipation, to blood clots. Ironically, the one thing they’ve never been linked with is weight loss! (10, 11)
2. Very unsustainable calorie target.
3. Very restrictive food choices, which is unsustainable and causes you to miss several key micronutrients.
4. Bulk of weight lost is simply water.

do fad diets help you lose weight and keep it off
  • The 17 Day Diet

Created by Dr. Mike Moreno, The 17 Day Diet advises you to change your calories and macronutrients every seventeen days.

Why seventeen days?

Cuz magic!

They claim that doing so will “confuse your metabolism” and “activate your skinny gene” (their words, not mine!). They’ll tell you to walk for 17 minutes per day, and to stop eating carbohydrates after 2pm, while working through four 17-day phases which have awesome names (‘Accelerate’, ‘Activate’, ‘Achieve’, ‘Arrive’).

There is no science to support their claims, but that didn’t stop it from becoming a best-seller.

Why The 17 Day Diet Doesn’t Work:

1. Despite claims you can lose up to 12lbs in the first 17 days (the ‘Accelerate’ phase) by “clearing your body of toxins which affect your metabolism”, it’s really just because you’re flushing a fuck-tonne of water from your body as a result of going low carb.
2. They instruct you to avoid eating carbs after 2pm in order to prevent it being stored as fat. This is another lie.
3. No calorie targets are provided, so the user has no idea how much to eat.
4. By phase four you’re ready to commit to buying their handy list of 17 Day Diet supplements for the rest of your life.

the atkins diet review
  • The Atkins Diet

The easiest way to lose weight with The Atkins Diet is to have a conversation with someone who is doing The Atkins Diet, because their stinky meat breath will make you hurl.

It’s a high fat, high protein diet where you’ll reduce carbohydates to under 20g/day.

This thing was a phenomenon in the late 1990s and early 2000s, when it pierced celebrity culture and even got a mention from Brad Pitt in Friends. It’ll go down in history as the first diet to create a cult-like following, where its users would often go bat-shit crazy in a bid to convert their friends and colleagues to their new-found way of life; a trend which has since been replicated by paleo, carnivore, keto, and others.

Why The Atkins Diet Doesn’t Work:

1. This is a very unsustainable diet model.
2. They’ll woo the customer with the promise of “lose up to 15lbs in the first two weeks”, but this is nothing more than water.
3. Users see an immediate weight regain when re-introducing carbohydrates to their diet.
4. The demonization of food groups is always a bad thing, but even more so here, because there was a period in the early 2000s where the whole world seemed to (incorrectly) believe that carbohydrates are directly responsible for weight gain, and it was largely because of this diet plan.
5. Hey there, cholesterol. (12)
6. You’ll never get a girlfriend with breath like that.

the alkaline diet debunked
  • The Alkaline Diet


It’s your old schoolmate Jill, and she’s offering you the chance to live your #dreamlife by signing up to her multi-level marketing scam home-based business opportunity selling juice shakes and detox capsules.

Welcome to The Alkaline Diet, where people believe they can change the body’s pH levels from acidic (“bad”) to alkaline (“good”) with nothing more than a miracle smoothie and a smug sense of superiority.

Your food choices are extremely restricted on this one, because you’ll be limited to fish, vegetables, seeds, nuts, and supplements. Yey!

Interestingly, the founder of this diet is now in prison for practicing medicine without a license. That should tell you all you need to know here.

Why The Alkaline Diet Doesn’t Work:

1. You can’t change your body’s pH levels from acidic to alkaline. You’d literally die. (13)
2. Very restricted food choices mean that this diet is both unsustainable and potentially dangerous, because it lacks several key micronutrients.
3. The vast majority of weight lost is nothing more than water, because carbohydrates are near zero.
4. Re-introducting carbs further down the line will see the immediate return of this water weight.
5. This whole thing is a sideshow to tie you into buying their over-priced supplements, upon which the person who lied to you signed you up generates a monthly commission.

do crash diets work?
  • The Raw Food Diet

Every workplace has a guy who calls himself a “hunter gatherer”, right?

Sure, Frank. I mean, catching those chicken breasts in the aisles of Tesco isn’t quite how the cavemen did it, but knock yourself out!

The Raw Food Diet is high protein, low carbohydrate model which states that you must eat all of your food raw (yes, even the meat). Yikes!

Why The Raw Food Diet Doesn’t Work:

1. This is a very unsustainable diet due to the highly restrictive food list and constant meal prep involved.
2. It’s very expensive, because everthing must be fresh.
3. Practitioners claim that eating food in a raw state preserves more micronutrients, but this is false. Some vegetables do lose a little nutritional value during the cooking process, but others actually need it in order to unlock their full nutritional contents.
4. Eating raw meat is not only disgusting, it’s downright dangerous.
5. By placing such restrictions on food, this becomes just another low carb diet, so the vast majority of any weight lost is nothing more than water – all of which will be regained when you inevitably get tired of living like a fucking idiot and re-introduce carbohydrates.

In Summary

reasons why fad diets don't work

Fad diets are the “get rich quick schemes” of the nutrition world.

They simply do not work, but they’re very easy to get sucked into because of the God-level marketing which surrounds them when they’re on trend.

In reality, achieving a fantastic physique is much easier than these convoluted diet plans will have you believe. All you have to do is lead a healthy lifestyle and be consistent. Job done!

  1. Van Dyke N., et al. Review Article Relationships between intuitive eating and health indicators: Literature review. Public Health Nutrition (2014).
  2. Schaefer, J. T., et al. A Review of Interventions that Promote Eating by Internal Cues. Journal of the Academy of Nutrition and Dietetics (2014).
  3. Bruce, L. J., et al. A systematic review of the psychosocial correlates of intuitive eating among adult women. Appetite (2016).
  4. Howell S., et al. “Calories in, calories out” and macronutrient intake: the hope, hype, and science of calories. Am J Physiol Endocrinol Metab (2017).
  5. Leibel R.L., et al. Energy intake required to maintain body weight is not affected by wide variation in diet composition. Am J Clin Nutr (1992).
  6. Tiwari S., et al. Insulin’s impact on renal sodium transport and blood pressure in health, obesity, and diabetes. Am J Renal Physiology (2007).
  7. Smith C. F., et al. Flexible vs. Rigid dieting strategies: relationship with adverse behavioral outcomes. Appetite (1999).
  8. Stewart T. M., et al. Rigid vs. flexible dieting: association with eating disorder symptoms in nonobese women. Appetite (2002).
  9. Malik N., et al. Are long‐term FAD diets restricting micronutrient intake? A randomized controlled trial. Food Sci Nutr (2020).
  10. Birmingham, C. L., et al. Human chorionic gonadotropin is of no value in the management of obesity. Can Med Assoc J (1983).
  11. Lijesen, G. K., et al. The effect of human chorionic gonadotropin (HCG) in the treatment of obesity by means of the Simeons therapy: a criteria-based meta-analysis. Br J Clin Pharmacol (1995).
  12. Retterstol K., et al. Effect of low carbohydrate high fat diet on LDL cholesterol and gene expression in normal-weight, young adults: A randomized controlled study. Atherosclerosis (2018).
  13. Angeloco L., et al. Alkaline Diet and Metabolic Acidosis: Practical Approaches to the Nutritional Management of Chronic Kidney Disease. J Ren Nutr (2018).

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I’m Russ. I’ve been a personal trainer since 2002, and I own

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