Mark Sisson says that body composition is 80% diet. My experience backs that up.
In 2009 I trained for a 17 mile race for four months, upping my mileage the whole time. At the time I had always heard that runners needed lots of carbs, so I was eating pasta, rice, and other carb heavy foods every day. With all that exercise I never lost a pound.
I started moving to primal/paleo eating a few months later and dropped 10-15 lbs in about three weeks. Plus my after lunch headache and foggy feeling went away.
Probably been eating this way for three years now and can tell a big difference in the way I feel and in my physical ability.
Crap food makes you feel like crap. Great food makes you feel great. Go figure.
