English subtitling fail on weights

So the women's weights are mentioned very specifically in the film & credits. The lowest weight is Marta, at 45 kg, and she's below Benito's ideal weight; no ideal what he says in Spanish as a number for the latter, tho' a review on here suggests 47 kg.

Now, 45 kg is 99 lbs, yet the subtitling keeps insisting that Benito's favourite weight is considerably less than that - 84 lbs, IIRC, which is a whisker over 38 kg. What's going on? Are subtitlers really that lax? How could someone get a number so massively wrong when they're supposed to be capable of translating true dialogue into finessed short form?