Why Diets Don't Work

Written by Nina Weiss, Accredited Practising Dietitian and Credentialed Eating Disorder Clinician.

Have you ever been on a diet?

Have you ever tried to cut out certain foods or follow a rigid, restrictive meal plan to lose weight or "improve" your health?

If so, you're definitely not alone.

Body dissatisfaction is common and a key factor that leads many people to start dieting. These attitudes often begin early in life and may persist well into adulthood. In fact, in 2024, around 75% of Australian adolescents aged 12-18 reported a desire to be thinner (1).

But what actually happens when we diet, and why do diets so often fail?

Why diets don't work

Diets that promise quick fixes or rely on rigid, restrictive rules are setting us up to fail. They deprive the body of adequate energy and essential nutrients. While this may be sustainable for a short time and lead to short term weight loss or other physical changes, eventually they lead to low energy levels, low mood and negative impacts on physical and mental health.

And despite their shiny promises, diets don't work!

Research shows that up to 95% of people who diet will regain the weight they lose (and sometimes more) within 1-5 years (2).

The Diet Cycle

When the body experiences dietary restriction, it responds as if it is in a state of starvation.

Hunger signals increase due to fat loss and reductions in the hormone leptin, while metabolism slows in a an attempt to preserve body mass.

Thoughts about food- what to eat, when to eat, how much to eat, may become consuming (read more about food noise here). Eventually, physiological and psychological drivers override our "willpower" and many people will end up breaking their diet rules.

The result?

Feelings of guilt, disappointment, failure- often accompanied by confusion about what went "wrong" or why you are lacking "willpower".

For most people, this feeds straight back to body dissatisfaction and a renewed desire to start another diet.

Again...and again...and again!

So how do I get off the dieting hamster wheel?

1. Shift the focus from weight to health

   Instead of eating with a sole aim of weight loss, focus on how food supports your energy, mood, movement, concentration and overall wellbeing.

   
   

   If weight loss is a goal and appropriate for your health, an eating disorder informed dietitian can support this in a way that is sustainable and non-restrictive.

2. Eat regular, nourishing meals

   Aim to eat every 3-4 hours during the day to keep your energy levels stable. Skipping meals or under-fuelling increases hunger hormones and food-seeking thoughts, which can increase the risk of overeating later in the day.

3. Don't eliminate foods or food groups

   Avoid labelling foods as "good" or "bad". All foods can fit within a balanced pattern of eating- this includes foods you enjoy and those eaten during social occasions with family or friends.

4. Build alternative ways to cope with difficult emotions

   Food can provide us with comfort, relief or enjoyment during times of stress, boredom or emotional overwhelm. Learning to recognise these patterns and developing alternative coping strategies- like calling a friend, getting outside or watching your favourite TV show can be helpful.

5. Reach out for support

   Breaking free from the dieting cycle alone is hard, especially if it’s been part of your life for years. Support from a healthcare professional such as a dietitian or psychologist with eating-disorder experience can make a big difference.

I have supported many people to step away from dieting by helping them to reframe their relationship with food and their bodies, and supporting them to make sustainable, positive nutrition changes.

If you'd like to get started, get in contact here.

References

1. https://butterfly.org.au/get-involved/campaigns/youthsurveyfindings/

2. Bijlefeld, M. and Zoumbaris, S.K., 2003. Encyclopedia of diet fads