The Real Reasons Why Diets Fail

If diets really worked we wouldn’t need a $586 billion global weight loss industry, argues Dr Jenny Brockis.

As our waistlines continue to expand, obesity has become a global pandemic associated with a higher prevalence of type-two diabetes, heart disease, cognitive decline and premature death. So why is sustainable and enduring weight loss so hard and why does our brain set us up to fail? Here, Dr Brockis reveals the main reasons diets fail.

Genes rule

Genetics play a huge role in how your body looks and functions. In “big-boned” families, kids tend to follow their parents. If we become obese as adults, we pass on some epigenetic changes, predisposing our future offspring to obesity as well.

Consider your 'set point'

Our 'set point' is the weight range your brain determines as being your “ideal” - whether you agree with it or not! Losing weight below your set point can sometimes pitch your brain against you, as it is seen as a sign you are starving. This kick-starts metabolic and hormonal functions to restore your weight to its original level - sometimes with an extra kilogram or two in case you fall back into that dangerous zone of not having enough food. This metabolic change persists over time, meaning we become less efficient at converting our food to "fuel", and more prone to regaining that weight.

You're not hungry because of a lack of willpower

Most of us eat because we are hungry, upset, stressed or because we are being polite. Reducing food intake makes us hungry, more stressed and we feel deprived. It’s hard to concentrate when your mind is thinking about how long before your next meal. Willpower is a finite resource that reduces across our day. That’s why it’s easier to keep to our intention of eating healthily early on, because by dinnertime we are far more susceptible to the Sirens allure of that chocolate brownie and vanilla ice cream for dessert.

Food can be addictive

Hedonic hyperphagia or 'eating for pleasure' (as opposed for fuel) develops because the brain reacts to certain foods that light up our 'reward circuitry'. Sugar is particularly responsible for this. No wonder we find it hard to overcome our food cravings! The more we succumb to our addiction, the more we have to consume to feel satisfied. 

The solution?

Let’s remove the word 'diet' from our vocabulary and instead focus on making healthier food choices that gradually redirect our brain’s preferences. Adopting a mindful approach to what and how we eat makes it easier to pick up our brain’s cues that we are hungry or full.

Three tips to win the battle of the bulge:

  1. Focus on how you feel, not what you weigh. Ditch the diet and the guilt.
  2. Eat real food – mostly plants, and not too much. Moderation rules.
  3. Look for ways to create a healthy relationship with your food and enjoy the benefits of a happier you.

Dr. Jenny Brockis is the Brain Fitness Doctor. A medical practitioner, speaker and author of 'Future Brain: The 12 Keys to Create Your High-Performance Brain' (Wiley). She specialises in brain health and the science of high performance thinking. Visit her website:

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