Why Your Body Fights Weight Loss
Ask anyone who’s tried to lose weight...
they’ll tell you the same thing:
"It’s harder than it should be"
And that’s not because their doing it wrong!
Once excess weight has been around for a while, your body doesn’t stay neutral...
It adapts!
And, unfortunately, those adaptations don’t favour weight loss.
The Climate Change Analogy
The way I describe this to clients is by using the example of climate change...(bear with me)
At first, small changes don’t seem to matter:
A bit more food
Less movement
More stress
Worse sleep
Nothing dramatic happens!
But once you pass a critical threshold, much like the 1.5°C tipping point discussed in climate science, the system starts to run away from you.
(See, told you it would make sense.)
With climate change, we are told:
Ice melts = less reflection of heat = more warming
In weight gain:
Fat accumulates = hormones shift = fat gain compounding
At this point, you’re no longer tweaking your diet or improving your lifestyle, or adding in a bit more exercise.
You’re pushing against your own physiology.
A system that is now actively geared towards weight gain...
...not weight loss.
The Hormonal Snowball Effect
Here’s what tends to happen as excess weight accumulates:
Insulin rises:
As fat tissue expands, it becomes increasingly insulin-resistant. The pancreas compensates by producing more insulin. Higher insulin makes it harder to access stored fat.
Leptin signalling becomes resistant:
Leptin is meant to signal fullness and adequate energy stores. But chronically high leptin leads to leptin resistance.
So despite plenty of stored energy:
Hunger remains high
Satiety signals weaken
Inflammation increases:
Fat tissue isn’t dormant squidge....it’s hormonally active tissue. As it expands and increases, it releases inflammatory messengers that:
Worsen insulin resistance
Disrupt appetite regulation
Interfere with thyroid signalling
Metabolism adapts defensively:
When weight loss is attempted, the body often responds by:
Reducing your baseline calorie burn
Hunger hormones increase
This makes movement feel harder
This isn’t sabotage...
It’s survival biology!
Why “just eat less” stops working
This is why people often say:
“I’m eating less than I ever have… and nothing’s moving.”
From your body’s perspective:
Energy availability looks threatened
Stored fat feels worth protecting
Weight loss feels like a risk, not progress
So the system pushes back.
This is NOT a character flaw.
It’s a physiological response that has been well documented in research:
What the science shows
This study found exactly what I have described above:
Following weight loss, the body adapts through hormonal and metabolic changes, which:
Increase hunger
Reduce energy expenditure
Lower resting calorie burn
Crucially, many of these changes were shown to persist for at least a year!
Why this matters
When I talk to clients, many of them don't understand this and they blame themselves.
They assume:
They’ve failed
They lack discipline
They need to try harder
In reality, the rules of their biology changed without them realising!
This matters, because until you understand this, it’s very easy to chase the wrong solution or to think the problem is you!