It is understood as "stocky, solid, solid", although it is sometimes used as "fat", but it is more of a euphemism. It is formed by chunk ("mazacote, large piece of something") the suffix -y (to create adjectives).
It is clear that Ingles/chunky ("robust, corpulent") is not a Word in Spanish, nor is it used in our language.
Name of a pet food brand. The word is of English origin and means strong, vigorous, burly.
CHUNKY anglicism by FORNIDO