The most common and most likely answer to this crossword clue is the 5 letter word PUDGY
I've seen this crossword clue in The Guardian
P
U
D
G
Y
Buddy explains!
The straight part
We know that "What you get from sweet food and extremes of gluttony?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case what you get from sweet food and extremes of gluttony? = pudgy.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does PUDGY mean?
PUDGY adjective- Fat, overweight (pertaining particularly to children), plump; chubby.