Originally Posted by
rubiksoval
Your point is wrong. 2500 kcal is roughly 2500 kJ.
It's not.
1 kilojoule (kJ) is 239 calories (cal) and therefore
1 kilojoule (kJ) is 0,239 kilocalories (kcal).
Conversely 1 kilocalorie is 4,184 kilojoule
And so 2500 kcal is precisely 10 460 kJ
Here's a wikipedia article about Joule
https://en.wikipedia.org/wiki/Joule
It helpfully lists conversions with other energy units, one of which is the calorie.