I asked some women what attributes are considered attractive here...they replied that it does not matter much whether one is skinny or chubby, just if they are "sexy". Can you explain?

They are right.  Chubby is as sexy as skinny.

Chubby can be considered a sign of good health or wealth in a country where food is scarce.

And since "Beauty is in the eye of the beholder (Sa'k lèd pou youn ka bèl pou yon lòt)", sexy can be whatever pleases you.

Usually, in Haiti, when someone says seksi, they mean nice bodily curves (chubby or skinny)