Why a small body cannot copy a big man's deficit
Your tall friend burns more calories than you do, even when you both sit still. So the big food cut that feels easy for him can push a small body below the safe calorie floor.
You share a desk with a tall friend. He cuts 700 calories a day and still eats a full thali at night. You try the same cut. By evening you are shaky, hungry, and ready to eat three samosas. It is not weak will. Your small body just runs on a smaller engine. This short read is about why his number does not fit you, and what to do instead.
Your engine is smaller than his
BMR means the calories your body burns at rest. It keeps your heart, lungs, and brain working. A bigger body burns more at rest, because there is more of it to keep alive. Scientists use a trusted maths rule called the Mifflin-St Jeor formula to estimate this. Picture a 50 kg woman who is 150 cm tall. Her rest burn is about 1,130 kcal a day. Now picture an 80 kg man who is 180 cm tall. His rest burn is about 1,780 kcal a day. That is about 650 kcal between them, just to stay alive. That gap is like six extra rotis he can burn and she cannot.
Why the floor stops the small body first
I can copy my tall friend's deficit and get the same result.
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His number works for his engine, not yours. Your daily maths is food calories minus your BMR and your active calories. Change the body and the maths changes too. Copy his 700 kcal cut and you may drop below the safe calorie floor for your size. Then you feel hungry, shaky, and stuck. The kilos stop moving. Your own smaller cut, kept up for weeks, beats his big cut that you cannot hold.
Smart maths for a small body
The bottom line
Your tall friend won the burn lottery, not the willpower lottery. His big deficit fits his big engine. Your small body needs a small, steady cut, kept above the safe calorie floor. Add a short walk, trust the weeks, and let Burnie show the maths each day. Small body, small cut, real results.