If eats a lot, also the letter k gets bigger
k is the prefix that indicates the 10 ³, ie the kilo-.
However, the brochure of a major pharmaceutical company would seem to suggest , "warning that
if k eats a lot, also the letter k becomes larger: k goes to K).
I'm not sure the font used is uppercase, but I think so.
But you assured, that even in systems with high calories, the value 10³ calories is still kcal (and not Kcal).