before i start yapping i should probably state that this has nothing to do with her after the shimmer and throughout season two as i suppose you could make the argument that she might not have to eat as much due to the shimmer then and i honestly just dont like season two, so this only applies to her pre shimmer in s1

REASON ONE

jinx has braids that go down to her ankles and her hair is thick, when not getting enough nutrients and being malnourished your hair will not be thick long and healthy

her hair is very much thick and very healthy, as very obvious in this gif

also she looks so majestic here holy shit

REASON TWO

she has pretty toned muscles

shes obviously not the most muscular girl ever, but she is definitely quite strong, she hauls around large and heavy guns like its nothing and id hope its pretty well known that if you dont eat enough youre not going to gain muscle as easily as someone who eats regularly would

REASON THREE

jinx exerts a lot of energy throughout s1 pre shimmer, she runs around, she fights, she jumps around, she moves around a lot and is just overall very active, if she was eating barely any food so much to the point that she was malnourished she would not be able to do half of the stuff that she does

REASON FOUR

silco is one of the richest men in zaun, he clearly has access to food and he himself isnt malnourished either, with jinx being his human weapon hes not going to let her just not eat, we can assume that she was eating enough to be healthy just because of this as it makes no sense for silco to manipulate her into being his weapon and then let her not eat as it would make her weaker

jinx is not malnourished, she is just skinny, but a lot of people online tend to think that her living in zaun and zaun being a poor city makes her have to be malnourished and unhealthy, and its just really annoying to see online whenever someone says anything about her or her body