https://scholar.google.ca/scholar?q=pesticides+obesity
On the flip side, there probably isn't enough land for everyone to eat organic, so it's not a global solution
Medical studies in general have a long way to go to catch up to even the stuff coming out of social-science and public policy journals.
"organic" is a marketing buzzword that doesn't have the meaning that you are told. USDA certified "organic" vegetables can be grown with tons of hormones and pesticides, provided they are organic in origin themselves. They can even use non-organic chemicals provided enough of the organics board decides an organic version is too costly.
https://www.usda.gov/media/blog/2012/01/25/organic-101-allow...