This Library database has reliable resources in many media on contemporary social issues. Explore the different aspects and points of view of fast food that people are talking about.
EBSCOhost is a collection of databases that all search similarly. Some cover all topics and some cover a single subject area. These links will take you to the ones most likely to work for you:
The National Institutes of Health is a US government agency that does lots of scientific research into all aspects of health and wellness, all presented for free on its website.
Use Google's Advanced Search to limit your internet searching to US government agencies. Just look for the "site or domain" box and type in .gov.