Perhaps the most common modern diet fad is the idea of a 3 day diet plan.
There are a number of different variations on the diet, but one thing they have in common is hype.
For example, the diets often claim that you can lose 10 pounds in 3 days.
That’s a pretty extreme amount of weight loss.
Does the diet actually help you lose that much weight? And if so, is it healthy?
That’s what we’re going to find out.
In this post, I’m going to look at the 3 day diet plan in depth and show you its implications for weight and for health.
What is the 3 Day Diet?
The idea of a 3 day diet has become pretty popular.
The name gives away the general idea of the diet. Essentially, you are following a specific eating approach for 3 days. Doing that is supposed to have dramatic effects on your weight.
But, does it?
Right now, the 3 day military diet seems to be the most popular variation of a 3 day diet.
The 3 day military diet involves following a strict (and slightly strange) diet plan for 3 days and a more conventional (low calorie) diet for the rest of the week.
In fact, the diet has been promoted over and over again on different websites.
Sometimes it is called the 3 day military diet, but other times it is just called a 3 day diet.
I’ve talked about this diet in the past, so I’m not going to go into it in-depth here.
However, the image below shows the basic meal plan for the diet.
I’ve noticed that some sites do vary this meal plan a bit.
For example, the menu below is a meal plan given for the third day of the diet from a completely different site.
There are a lot of similarities although there are some differences as well.
There are also other types of 3 day diets out there that are quite different.
In general though, 3 day diets focus on having a 3 day period that is very challenging.
Typically, this will be a period where you are taking in a very low amount of calories (often between 800 and 1,000 calories per day).
In some cases, that might be the extent of the diet while in other cases, you might follow up with something different for the other 4 days of the week.
Even though these diets can be vastly different than one another, their similarities are important to talk about.
Some History of the 3 Day Diet
I also want to point out that the 3 day diet concept isn’t new.
This is particularly true for the 3 day military diet.
For example, if you look at the search trends from Google for the 3 day military diet, you’ll see that the diet has been pretty popular recently.
But, the diet itself has been around online a lot longer.
For example, I found one forum post from 2007 detailing the same basic strategy, just under a different set of names.
This history really shows that there is nothing spectacular about the diet.
It is simply an approach that gets recycled from one year to the next.
Sometimes the name changes, sometimes some of the details change, but the basic concept remains the same regardless.
If you add the term 3 day diet to the same graph, you get this pattern:
So, the concept of a 3 day diet has been around for quite some time.
But, what about the diet itself? Is it any good?
Want to Lose Weight and Keep it Off?
Long-term weight loss doesn’t come from a crash diet or a popular fad. Instead, it is connected to sustainable habits and healthy foods.
Does the 3 Day Diet Work?
The popularity of fads like the 3 day diet comes from the fact that they seem to work.
I think in some cases, the difficulty of the diet also makes a person feel like they are doing something really great for their body.
But, are they really?
The first thing is that yes, the 3 day diet plan does work.
With a 3 day diet, you would lose weight.
However, you probably wouldn’t lose 10 pounds for every week that you followed the diet.
You might lose that much in the first week, simply because a lot of the weight that you’re losing would be water weight (although many people probably don’t lose 10 pounds even in the first week).
If you kept following the diet for another week or two, then you would probably find yourself losing much less weight.
Regardless though, you would probably lose some weight as long as you were on the diet.
That isn’t because the diet has a ‘secret’ combination of food or anything like that.
Instead, the outcome is simply because you are consuming fewer calories than you are using. That’s also the concept behind weight loss in general.
So, yes, you would lose weight.
Here’s the thing though.
Weight loss isn’t hard.
I know how bad that sounds, but it’s true.
In and of itself, losing weight isn’t very difficult.
The challenge is consistently losing weight and keeping that weight off.
That issue is why there are so many weight loss diets to begin with and such a large number of people looking for weight loss secrets.
A 3 day diet doesn’t really offer that.
Instead, it just offers a way to get weight off fast.
If you were able to keep that weight off after the diet, then it might be a good way to lose some weight.
But, could you?
In most cases, if you need to turn to something like this to lose weight, then you probably don’t have the tools to keep the weight off either.
And that’s where the problem lies.
For example, this person in the online forums had this to say about the diet:
In reality, I think this type of diet is popular because people see some fast visible weight loss.
If people don’t lose as much as they wanted, or if they gain that weight back, then they blame themselves, rather than the diet.
That pattern happens a lot with diets.
In fact, that’s part of the reason that this type of diet can stay popular, even though most people probably don’t see any long-term benefits from the diet.
Nutrition and Yo-Yo Dieting
In general, a 3 day diet is designed to be a way of losing weight fast.
Often, the diet plan isn’t nutritionally sound, so you couldn’t follow it in the long-term without compromising your health.
Additionally, the challenging nature of the diets means that most people probably couldn’t follow them in the long-term anyway.
But, what’s the harm in losing weight fast?
In fact, other research has even indicated that losing weight fast may contribute to better long-term weight loss outcomes (3).
So, losing weight fast could be a good thing.
The problem is that most people following this type of diet don’t really know how to keep that weight off.
As a consequence, they lose weight relatively fast but they gain it back quickly too.
That leads to a pattern called yo-yo dieting.
With yo-yo dieting, you diet for a while and lose some weight.
Once you stop that diet, you tend to gain all of that weight back.
In some cases, people end up regaining more weight than they lost.
Fad diets are one key reason for this pattern.
When people start a fad diet they tend to get excited and for a while, they follow it strictly. But, adherence to any diet is difficult, especially if you are following one that is strict or one that doesn’t match your lifestyle.
That’s especially true for diets like the 3 day diet because they simply aren’t designed to be followed in the long-term.
The Risks of Yo-Yo Dieting
Yo-yo dieting is frustrating.
If you’re yo-yo dieting, you feel like you’re getting nowhere because you aren’t able to get weight off and keep it off.
Research hasn’t focused on yo-yo dieting much, but it’s easy to see how this process could have major implications.
After all, our bodies consist of a range of interconnected systems.
Changing our weight has implications on many aspects of our body.
For example, losing fat impacts our body composition, which has downstream impacts.
Likewise, our weight and body composition affects our hormones, such as the hunger hormone leptin.
A lot of the time, people are yo-yo dieting because they are following unrealistic short-term diets.
Many of these diets aren’t nutritionally balanced, so people who are yo-yo dieting might find that they are deficient in some nutrients.
That approach could have significant effects on overall health.
Yo-yo dieting also has mental implications.
I’m not just talking about frustration here.
Yo-yo dieting can make people feel bad about themselves and it can make them feel like they are a failure.
In turn, this can have other implications for mental health, including low self-esteem and higher levels of stress. Those factors could even contribute to the development of depression.
At the same time, people who yo-yo diet may start to turn to extreme approaches to lose the weight and keep it off.
Fad diets are one example of this, but so are issues like eating disorders.
This creates a dangerous pattern because most extreme weight loss approaches are very difficult to maintain.
So, following an extreme approach would make yo-yo dieting more likely, which contributes to that overall cycle.
Finally, it’s very possible that yo-yo dieting has more severe implications for health, such as increased disease risk.
That research hasn’t been done yet, so we don’t know what effects yo-yo dieting does have.
But, bouncing your body between different weights can’t be healthy.
Successful Weight Loss
The most important secret to weight loss is finding an approach that you can follow consistently.
The idea is that you don’t diet per se.
Instead, you change your lifestyle in a way that promotes weight loss and improved health overall.
For some people that change might be following the Paleo diet, for others, it might involve following a low-carb diet or just moving towards eating healthy and whole foods and away from processed foods.
Realistically, the change that works for someone else mightn’t work for you.
If you’re going to follow a 3 day diet to lose some weight fast, I’d suggest having a healthy lifestyle in place first.
That way you can go back to that lifestyle after you have lost the weight you wanted to.
This approach would give you the ability to keep off the weight that you lose.
What About Body Composition?
Here’s another thing to think about. Body composition.
Unsurprisingly, discussions about diets focus almost exclusively on weight loss. Specifically, the emphasis is always on fat loss.
But, that’s only part of the story.
Being healthy involves having a good body composition.
This means that you need to be gaining muscle and losing fat.
Yet, many diets (particularly fad diets) simply restrict calories. In doing this, they contribute to fat loss and muscle loss.
The end result is a health issue that most of us don’t even think about.
This is known as skinny fat.
I know, I know. That sounds like a contradiction in terms.
It’s not though.
In general, ‘skinny’ refers to having low levels of muscles, while ‘fat’ refers to having too much fat.
So, a skinny fat person would have a body composition that is high in fat compared to the amount of muscle. Physically, that person might look thin, but not toned.
I bring this up because if you successfully lost weight through the 3 day diet (and kept it off), you would end up in the skinny fat category.
In scientific literature, this issue is sometimes called normal weight obesity.
The implication is the same – because it means you can be fat, even if your weight is relatively low.
That’s a problem because this body composition isn’t especially good for health.
Our muscles play important roles in our body and in our overall health.
This includes an increased risk of death from heart disease (6).
The presence of health issues does make a certain amount of sense.
After all, some (not all, just some) of the health complications of obesity come from our body composition, not the sheer amount of fat we have.
So, even if we are thin – a high proportion of body fat is still going to have negative implications for our health.
To get around this, you need to have enough protein in your diet and you also need to be doing some work to gain muscle.
That would typically include approaches like resistance training and working with weights, along with getting enough protein in your diet.
You also need to avoid diets that will make you lose muscle along with fat.
Ideally, you want to be gaining muscle and losing fat at the same time.
The concept of carb cycling is sometimes promoted as one way to gain muscle while also losing weight.
It's also worth remembering that a very low calorie diet will typically mean that you lose muscle and that type of diet certainly won't let you gain muscle.
After all, you need energy to build muscle and a very low calorie diet doesn't offer much energy at all.
The Big Picture
Fad diets are everywhere.
Today, the focus is on 3 day diets, particularly the 3 day military diet.
Next month or next year, the focus may be on something else entirely.
This type of diet might offer fast weight loss, but that’s simply not enough on its own.
To keep weight off, you need a healthy lifestyle and a diet that is going to keep you at a healthy weight.
At the same time, you really want to be gaining muscle at the same time as losing weight.
There are many healthy approaches out there that can help people to lose weight, get enough nutrients and gain muscle.
But, the answers you need typically won’t be found in a fad diet.
Instead, they are found in diet and lifestyle changes that you can follow in the long-term.
Want to Lose Weight and Keep it Off?
Weight loss is a huge industry, with no shortage of bold claims. But, long-term weight loss doesn’t come from a crash diet or a popular fad. Instead, it is connected to sustainable habits and healthy foods.
Check out my most recommended products and guides to see where you can get started.
What are your experiences? Have you tried the 3 day diet plan? Did you lose weight and keep it off?