Why Crash Dieting Before Your Holiday Usually Backfires

Your holiday is just around the corner, and suddenly there’s a rush to “get beach body ready.”

You tell yourself:

“I’ll just eat as little as possible for the next two weeks.”

Out come the detox teas, juice cleanses, meal replacement shakes, no-carb diets, and hours of cardio.

While it might seem like the fastest way to lose weight, crash dieting is rarely the best solution. In fact, it can leave you feeling hungrier, more fatigued, and more likely to regain the weight afterwards.

Here’s why.

It Isn’t Long Enough to Lose a Significant Amount of Body Fat (Healthily)

One of the biggest misconceptions about rapid weight loss is that every kilogram lost is body fat.

In reality, when you dramatically reduce your calorie intake, the weight you lose during the first couple of weeks is made up of several things:

• Water

• Glycogen (the carbohydrate stored in your muscles and liver)

• Body fat

• Potentially some lean muscle tissue if protein intake and resistance training are inadequate

Because glycogen is stored alongside water, reducing your carbohydrate intake can cause the scales to drop quickly. While this can feel motivating, much of that initial weight loss isn’t actually body fat.

Meaningful fat loss takes time. Trying to lose several kilograms of fat in just two weeks would require an extremely large calorie deficit that is difficult to achieve while maintaining energy levels, training performance, and muscle mass.

Your Body Adapts to Extreme Dieting

When calorie intake drops significantly, your body responds by adapting to the energy shortage.

One of these adaptations is known as metabolic adaptation (sometimes called adaptive thermogenesis).

This doesn’t mean your metabolism is “broken.” Instead, your body becomes more efficient by reducing the amount of energy it uses.

Alongside this, your body may:

• Burn slightly fewer calories than expected for your new body weight.

• Increase hunger signals.

• Reduce feelings of fullness after eating.

• Cause you to move less throughout the day without even noticing, reducing the calories you burn through everyday activity.

These responses evolved to help humans survive periods when food was scarce. They’re completely normal—but they can make sticking to an extreme diet increasingly difficult.

Restriction Often Leads to Overeating

After weeks of eating very little, you finally arrive on holiday.

You’re surrounded by buffet breakfasts, ice creams, evening meals out, cocktails by the pool, and foods you’ve been avoiding for weeks.

There’s absolutely nothing wrong with enjoying these experiences - that’s part of what holidays are for.

However, after a period of severe restriction, many people find they’re significantly hungrier than usual and more likely to overeat.

This isn’t a lack of willpower.

It’s a normal biological response after prolonged calorie restriction.

Why the Scales Jump Up So Quickly

Many people return from holiday convinced they’ve “put all the weight back on.”

In reality, the first increase on the scales is often largely explained by water.

Eating more carbohydrates replenishes your glycogen stores, and glycogen is stored alongside water. This means your body naturally holds more water again, causing your weight to increase within just a few days.

If you’ve also been eating more calories than your body needs throughout the holiday, you may have gained some body fat too - but it’s usually far less than people fear after seeing the scales.

This is one reason why relying on short-term weight changes can be misleading.

The Crash Diet Cycle

For many people, this pattern repeats itself year after year.

Diet hard before the holiday.

Lose weight quickly.

Enjoy the holiday.

Gain weight afterwards.

Feel guilty.

Start another crash diet.

The problem isn’t the holiday.

The problem is relying on an unsustainable approach in the first place.

Repeated cycles of losing and regaining weight can make long-term weight management more challenging, particularly if they reinforce restrictive eating habits and an “all or nothing” mindset.

A Better Way to Prepare for Your Holiday

If you want to feel more confident on the beach, the best approach is to start earlier and focus on sustainable habits rather than quick fixes.

Aim to:

• Create a moderate calorie deficit rather than starving yourself.

• Eat plenty of protein to help maintain muscle mass.

• Include resistance training alongside regular activity.

• Prioritise sleep and recovery.

  
  

Not only is this approach more sustainable, but you’re far more likely to keep the weight off after your holiday too.

Remember What Your Holiday Is Really About

Your holiday isn’t a fitness competition.

It’s an opportunity to relax, spend time with family and friends, explore new places, enjoy great food, and make memories.

The healthiest approach isn’t trying to transform your body in two weeks.

It’s building habits that allow you to feel confident and healthy all year round - without needing to punish yourself every time a holiday comes around.

Because lasting results don’t come from the most extreme plan.

They come from the one you can actually stick to.