Most people think the body responds to calories. But the science is clearer than that. The body responds to meaning.
One of my favourite studies entitled “Mind over milkshakes” (Crum et al., 2011) showed this beautifully.
Participants drank the exact same 380‑calorie milkshake on two different days.
The only difference was the story they were told:
The “Indulgent” shake
Labeled as rich, high‑calorie and satisfying.
Their bodies responded accordingly:
Ghrelin (the hunger hormone) dropped sharply.
Their physiology behaved as if they’d eaten a substantial meal
The “Sensible” shake
Labeled as light, low‑calorie and restrained.
Same shake. Same calories. But this time:
Ghrelin barely changed!
Their bodies acted as if they’d eaten something insubstantial
The nutrients didn’t change. The mindset did. And the body followed the mindset.
This is a powerful reminder for leaders:
Your internal narrative isn’t just psychological, it’s physiological. Your beliefs shape your stress response, your energy, your body language, your tone, your performance.
The story you tell yourself becomes the signal your body obeys. Mindset isn’t fluff. It’s biology.