Many young people are getting fat for/through eating too much fatty
food.
Do both prepositions work as well for this sentence?
Thank you in advance.
I missed the chance to answer at 28 after the hour, like the other two, but I also think "from" works better.
I would use "by" if it was intentional - I'm getting stronger by lifting weights, but I'm gaining weight from eating too much junk food.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.