What Is Intermittent Fasting? Does It Actually Work and Is It Safe?

Plate with healthy food next to empty plate with clock representing intermittent fasting and eating window

Intermittent fasting is everywhere.

You’ve probably heard:

  • “It’s the best way to lose weight”
  • “It boosts your metabolism”
  • “It fixes everything from fat loss to hormones”

And at the same time:

Skipping meals sounds extreme

Is this actually healthy?

Does it even work?

If you’re unsure, that’s completely fair.

Working with people trying to lose weight, this is one of the most common questions. Intermittent fasting can work - but not for the reasons most people think.

By the end of this article, you’ll understand:

  • What intermittent fasting actually is
  • Whether it works for weight loss
  • If it’s safe
  • And whether it’s right for you

 

What Is Intermittent Fasting?

Intermittent fasting (IF) is not a diet.

It’s an eating pattern.

It focuses on when you eat - not necessarily what you eat.

Instead of spreading meals across the day, you eat within a set time window.

 

Common Types of Intermittent Fasting

16:8 Method

  • Fast for 16 hours
  • Eat within an 8-hour window

5:2 Method

  • Eat normally 5 days
  • Reduce calories significantly 2 days

Alternate Day Fasting

  • Eat normally one day
  • Fast or eat very little the next

The 16:8 method is the most common and practical.

 

Does Intermittent Fasting Actually Work?

Yes - but not because it’s special.

It works because it helps create a calorie deficit.

When you restrict your eating window:

  • You often eat fewer calories
  • Which leads to weight loss

Intermittent fasting is just one way to get there.

 

What Are the Benefits?

Some potential benefits:

  • Simpler eating structure
  • Fewer meals to plan
  • May reduce snacking
  • Can improve adherence for some people

But many claims are exaggerated.

It doesn’t:

  • “Boost metabolism dramatically”
  • “Burn fat faster than other diets”

 

Is Intermittent Fasting Safe?

For many healthy adults - yes.

But it’s not suitable for everyone.

Be cautious if you:

  • Have a history of disordered eating
  • Are pregnant
  • Have certain medical conditions
  • Struggle with energy levels

If fasting leads to bingeing, low energy, or stress - it’s not the right fit.

 

Who Is Intermittent Fasting Good For?

It can work well if:

  • You prefer fewer meals
  • You don’t feel hungry in the morning
  • You like simple structure

It’s not ideal if:

  • You feel overly hungry
  • You overeat later
  • You prefer regular meals
  • It disrupts your routine

 

Intermittent Fasting vs Calorie Deficit

This is the most important point.

Intermittent fasting is not better than a calorie deficit.

It’s just one way to achieve it.

You can:

  • Lose weight without fasting
  • Fail to lose weight while fasting

The method matters less than consistency.

 

Do You Need a Dietitian?

You might not need one if:

  • You’re seeing results
  • You feel good

But you likely do if:

  • You feel stuck
  • You’re unsure what approach to take
  • You’re not seeing progress

 

What Working With a Dietitian Changes

Instead of guessing, you get:

  • A structured plan
  • The right approach for your lifestyle
  • Adjustments based on progress

If you want to understand how that support works, this guide on what a dietitian does explains it clearly.

Whether that includes fasting or not.

 

Final Thoughts

Intermittent fasting isn’t magic - but it can be useful.

The key is:

  • Finding what works for you.
  • You don’t need to follow trends.

You need a method you can:

  • Stick to
  • Feel good doing
  • Sustain long-term

If you’re based in Sydney or working online, working with a dietitian in Sydney can help you choose the right approach - instead of guessing.

Written & reviewed by
Andrew Wild, Director, Physiotherapist & S&C Coach at Wild Physio Fitness

Andrew Wild

Director, Physiotherapist & S&C Coach

Andrew Wild is the founder of Wild Physio Fitness and a physiotherapist, strength & conditioning coach and nutritionist. Former Head Physiotherapist at the Sydney Swans Academy, he treats you with the standard of care given to elite athletes.