5 reasons why you should avoid crash dieting

5 reasons why you should avoid crash dieting


Crash dieting is when you eat a very low-calorie diet with the goal to lose weight. You might be inclined to go on a crash diet before a big event, such as a wedding or a holiday, but it’s not an effective long-term solution for weight loss. Although you may see fast results at first, it won’t take long for your crash diet to, well, crash!
If you’re considering a crash diet to lose weight, we’d encourage you to read this guide first. We’ll teach you what crash dieting is and list 5 reasons why you should steer clear of it. If you’re trying to lose weight, it’s important to do so healthily and safely. Sacrificing a good relationship with food isn’t worth being able to button up those jeans, trust us! 

What is crash dieting?

A crash diet is defined by eating less than 800 calories (3,300 KJ) per day, and it’s not commonly recommended as a healthy or an effective long-term treatment for weight loss. Not only will you be battling horrific hunger pangs, but you’ll be missing out on all of those vital vitamins and nutrients from your regular food intake.
It’s sometimes referred to as the ‘semistarvation diet’, but you don’t need to starve yourself to lose weight. Losing weight should be a balance of healthy, more informed food choices and exercise. 
However, very low-calorie diets are occasionally considered for obese and severely obese people who are managing diabetes, going to have surgery or preparing for fertility treatment. Crash dieting should never be the first option for weight loss and it isn't routinely suggested by healthcare professionals.
You may recognise some crash diets in the form of shake, juice and detox diets, while some may even encourage you to skip meals, all intended for you to achieve rapid weight loss in a short period of time.

Do crash diets work?

The short answer is no, crash diets don’t work. Although you may lose weight quickly by going on a crash diet, it isn’t a long-term solution to maintaining the weight you’ve lost. In fact, most people gain the weight back after crash dieting as they’re likely to revert back to old food habits.
Ultimately, crash dieting is rarely recommended as a suitable way to lose weight because of the negative impact it has on your physical and mental health. Below we’ll discuss the reasons why you should avoid crash dieting and instead choose healthy, long-term weight loss methods that you can keep up with.

Why you should avoid crash dieting

What can happen if you opt to go on a crash diet? It’s more than just feeling hungry or losing weight in a short period of time. It can negatively affect you in other ways, too.
If we’ve not swayed you against crash dieting, keep reading to find out what can happen to you when your body isn’t getting the nutrients it needs to function normally.


Slowed metabolism

When you have a high metabolism, it means that you’ll burn more calories while at rest. But if you go on a very low-calorie diet, our bodies will slow down the metabolic rate to preserve energy.
This was a helpful, often necessary tactic learned by our ancestors when food was scarce, but not so much for us in the modern day. Having a slow metabolism means we burn less calories at rest, something that isn’t useful when you’re trying to lose weight!

Negative relationship with food

Often, crash dieting can cause you to have a negative relationship with food. When you’re on a crash diet, you’re essentially putting your body through a period of starvation, a punishment, perhaps, for eating too much food.
Rather than food being portrayed as the thing that nourishes your body and provides energy to get you through the day, food becomes the bad guy, the thing you have to avoid.

Lack of energy

To get energy, our bodies take it from the food we eat. But if you’re crash dieting, you’re likely to feel fatigued, dizzy and weak, especially if you’re not getting enough carbohydrates in your meals.
Eating small amounts of carbohydrates–or sometimes none at all, depending on the diet–is encouraged in crash diets, however, carbs aren’t the enemy. They provide us with energy to allow our brain and body to function as it should.

Hair Loss

To achieve healthy hair, it’s not just about the products you use, but what you put in your body. Your hair needs vitamins and minerals, protein and healthy fats to stay strong, shiny and healthy.
If you’re on a crash diet, odds are, you’ll be lacking these essential nutrients and your hair can suffer the consequences, even causing hair loss in some people.

Mood changes

Not eating enough calories throughout the day can impact your mood – you may feel low, irritable and experience poor concentration. In other words, you’re likely to be in a constant state of ‘hangry’, which isn’t pleasant to be around!

Most of us want to shed a few pounds now and again, especially after a Christmas binge or before a sunny beach holiday. But that doesn’t mean crash dieting is the answer.
Rapid weight loss isn’t healthy for your body or your mind. So if you’re looking to lose weight, it’s important that you do it healthily and safely to enable you to keep the weight off in the long-term. If you need further information about crash dieting, visit the NHS website.

Alexandra Moses - Medical Content Writer
James O'Loan - CEO & Superintendent Pharmacist
James O'Loan , CEO & Superintendent Pharmacist on 14 March 2023
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