It’s easy:
Fat people have less self control than a junkie.
A junkie WANTS to get high. They are highly motivated and do whatever they can (lying stealing etc) to get high.
Fat people don’t want to be fat. They are fat despite their motivation
Fat people have less self control than a junkie.
A junkie WANTS to get high. They are highly motivated and do whatever they can (lying stealing etc) to get high.

Fat people don’t want to be fat. They are fat despite their motivation

^^^