"I found the simplest solution to looking bigger"
It basically means he found an easy way to look bigger.
Simple = Easy
Simplest = Easiest
Solution = To solve or an Answer
This is the way some people speak as we don't give it much thought, but just think of solution as the word 'answer'.
"I found the simplest (easiest) answer to looking bigger."
It's not the best english, but most people speak like this, and wouldn't think of it as a mistake unless you gave it much thought, as it's really not a mistake. If you get what i'm saying?