Social media is currently flooded with a new weight loss trend; so-called “mono diets”.
These things have been around for decades, but we’ve seen a resurgence in their popularity lately thanks to apps like TikTok and Instagram championing their “fast and easy weight loss results”.
Nope, don’t fall for it.
We’ve known for a long time that these type of diets do not work, and in many cases they can lead to severe health issues.
I think it’s shameful that social media enables those self-appointed “gurus” to preach such utter nonsense, so kick back and relax with a protein shake… because today “mono diets” are gonna get scientifically wrecked.
What Is A “Mono Diet”?
It’s based around the concept of eating one single type of food.
There have been several popular models over the years:
- Cabbage soup diet
- Fruit diet
- Egg diet
- Chicken diet
- Twinkie diet
- Banana diet
Why “Mono Diets” Don’t Work
There are a few reasons why these diets rarely work.
Let’s take a look at them now.
- They’re Too Boring
The #1 ingredient in a successful weight loss diet is sustainability. (1)
Unfortunately people who have never been successful with their diet in the past tend to decide that they want to lose weight and then expect it to happen overnight, which opens the door for these “gurus” to cash in on their thirst for instant results.
Most people will start quite well, but then quickly get bored with the tiny list of so-called “good foods” that they are allows to eat. This causes them to fall off the rails (usually at the weekend), and a lot of people get trapped in a cycle of starting, crashing, and re-starting.
- They Lack Too Many Crucial Micronutrients
One of the main benefits of eating a balanced diet is that you’ll get a wide range of vitamins and minerals.
These micronutrients help our body with everything from the strength of your fingernails, the shininess of your hair, the health of your skin, your overall mood, your energy levels, and more.
Restricting our diet to one sole food (e.g. cabbage soup) eliminates almost every micronutrient and we miss out on all those benefits. This was common during the early 1900s, when sailors would get scurvy as a result of eating only fish and rice for months at a time, but there’s no reason for it to still be a thing in the 20-fucking-20s, people!
- They Don’t Give You Enough Protein
I’m guessing you don’t just want to lose weight, you want to look great.
You need to protect your lean muscle tissue in order to do that, which means getting plenty of protein into your diet. A so-called “mono diet” fails to accommodate for this factor because the majority of them focus on eating low calorie carbohydrate-based foods. (2)
On the rare occasion where we see a “mono diet” which uses a protein-based food (e.g. chicken) the problem still persists, because you are restricted to the small selection of amino acids contained within that sole protein source. There’s 22 amino acids in total and our body needs them all, so this is why it’s important to eat a varied diet.
- We Want Fat Loss Not Water Loss
Notice how many of the “mono diet” testimonials mention losing X number of lbs within the first few days?
It’s not a coincidence.
The body flushes a lot of water out of its system during the early stages of restrictive diet plan, creating the illusion of fat loss, and fooling people into believing that the diet plan is doing the work.
The flushing process lasts approximately 7-10 days while your body adjusts, and then you’ll hit a brick wall where results stop dead in their tracks.
Of course, the creators of “mono diets” aren’t telling you that the vast majority of what you’ve lost so far is just a bunch of water, so you’re left scratching your head trying to figure out why your weight loss results just flatlined.
It’s frustrating as a motherfucker.
- It Still Ultimately Comes Down To Calories In Versus Calories Out
The “gurus” who promote these diet plans want you to believe that there’s some kind of magic formula at work here, but there’s not.
At the end of the day it all comes back to the law of thermodynamics (calories in versus calories out), and if you were to follow a “mono diet” like The Cabbage Soup Diet but eat an absolute fuck-tonne of the stuff (unlikely, but go with it) then you would still gain weight. (3, 4, 5, 6, 7, 8)
The reason I dislike the kind of marketing we see on “mono diets” is because they encourage people to believe there’s some kind of sorcery at work, and it can lead to developing an unhealthy relationship with food.
For example, we commonly see them demonizing individual macronutrients (e.g. fat), or pushing the false belief that certain ingredients are the root cause of obesity (e.g. sugar), but in reality it’s all about the numbers and you can eat whatever the fuck you want as long as you stay within your energy requirements. (9)
- It Promotes Binge Eating
An ultra-restrictive diet leads to boredom, which causes most people to binge eat.
The small number of participants who are able to stick to the diet plan for long enough to hit “the wall” that I mentioned in the previous section usually meet the same fate, due to sheer frustration.
In most cases, people actually finish heavier than when they started, but if we look a little closer we can see that there’s an even worse issue bubbling beneath the surface; lots of people end up beating themselves up for their crashing off their diet, and they respond by trying something even more extreme the next time out, while remaining totally unaware that the diet itself was the problem all along!
Fuck that with a capital fist.
Why Are “Mono Diets” Still Popular?
Honestly, because people continue falling for their bullshit weight loss claims.
There will always be a charlatan ready to cash in on naivety, and the fitness industry is fucking riddled with it because everybody wants easy results.
Heck, in the mid-2010s a social media influencer who called herself “Freelee The Banana Girl” managed to write a best-selling novel selling her own version of a “mono diet” which was based around eating nothing but (you guessed it!) bananas!
Another example recommends we eat nothing but carrots, and then there’s the infamous “Twinkie Diet”, and even the “Milk Diet” (sold by two doctors, no less!).
It’s like the wild fucking west.
Speaking of Hollywood, when preparing for his role in Jobs (2013), Ashton Kutcher tried a “mono diet” which consisted entirely of fruit in order to drop weight for the role.
He ended up in hospital, and has since spoken about the ordeal:
“I did a mono diet called the fruitarian diet. Two days before we started shooting this movie I ended up in hospital, doubled over in pain. The doctors said my pancreas was struggling due to my diet. It was a terrifying experience.”
– Ashton Kutcher
Kutcher’s ordeal came some 17 years after Matt Damon had already attempted a “mono diet” while preparing for Courage Under Fire (1996) and warned everyone of the dangers.
Damon’s food was chicken, and as soon as the movie wrapped he swore never to return to this kind of nutrition plan because his doctor warned he was in danger of causing permanent damage to his heart.
He doesn’t speak about the experience too fondly:
“I had to run about 13 miles a day, which wasn’t even the hard part. The hard part was the diet. It helped with my on-screen performance because my character was supposed to be a wreck, and I certainly felt like one! I experienced dizzy spells and hot flushes every single day, and eventually I saw a doctor who told me that this type of dieting would cause permanent shrinkage to my heart if I continued. So yeah, it didn’t do me any good.”
– Matt Damon
Russ’ Take-Home Advice
Show me someone who is promoting the idea of a “mono diet”, and I’ll show you two things:
- Somebody who doesn’t know very much about nutrition, or
- Somebody who is trying to sell stuff.
These motherfuckers are everywhere, so keep your wits about you.
The “mono diet” is often the first step towards an eating disorder, and if this posts stops just one person from attempting that madness I’ll be a very happy man. I hope you enjoyed the read.
Further Reading:
If you enjoyed this blog, then you’ll probably also like reading these.
>> Why I Ditched Clean Eating
>> Why Fad Diets Don’t Work
>> Eat For Success (Nutrition Plan)
References:
- Stewart T. M., et al. Rigid vs. flexible dieting: association with eating disorder symptoms in nonobese women. Appetite (2002).
- Morton R. W., et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med (2018).
- 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).
- Golay A., et al. Similar weight loss with low- or high-carbohydrate diets. Am J Clin Nutr (1996).
- Golay A., et al. Weight-loss with low or high carbohydrate diet. Int J Obes Relat Metab Disord (1996).
- Luscombe-Marsh N.D., et al. Carbohydrate-restricted diets high in either monounsaturated fat or protein are equally effective at promoting fat loss and improving blood lipids. Am J Clin Nutr (2005).
- Raatz S. K., et al. Reduced Glycemic Index and Glycemic Load Diets Do Not Increase the Effects of Energy Restriction on Weight Loss and Insulin Sensitivity in Obese Men and Women. J Nut (2005).
- Johnston C. S., et al. Ketogenic low-carbohydrate diets have no metabolic advantage over nonketogenic low-carbohydrate diets. Am J Clin Nutr (2006).
- Howell S., et al. “Calories in, calories out” and macronutrient intake: the hope, hype, and science of calories. Am J Physiol Endocrinol Metab (2017).