I would say yes. If you're fat, that could mean you are lazy.
If you are lazy, you are may not do well in school, or, do just the bare minimum to graduate or get an average grade. Therefore, your education is poor, and you are stupid.
TridenT is skinny and dumb, therefore skinny people aren't always smart.
The Nutty Professor was fat and smart, therefore fat people aren't always dumb.
I would say yes you get dumber as you gain weight.What about fat people who used to be skinny? Do you get dumberer as the weight goes on? If you lose the weight do you get smarterer?
Obesity vs. education
http://www.datamasher.org/mash-ups/obesity-vs-education-expenditure
