I became somewhat obssesed about diet years ago. And upon my research, the caveman/paleo lifestyle is not a diet, it's called eating healthy. I wasn't fat or sick, but wanted to eat healthier. So far in 8 months I've lost over 20lbs on diet alone. I dont starve myself and I dont exercise outside the normal routine of life.
1. Grains. Read the book wheat belly. Modern wheat is horrible for you. And it's in EVERYTHING. It a profit driven consumable that is junk. Don't eat it.
2. Sugars. See Grains. Over processed, horrible on your body.
3. Factory Dairy. Feed with grains. Shot up with antibiotics, growth hormones and just horrible living conditions. (I took myself off store milk and started drinking raw milk and my chronic ear infections were gone!) Turns out, many people are allergic to dairy and just dont know it.
Cut out those 3 things and you're on your way. No fads, no products to sell, just good clean eating. This includes animal fats, veggies, fruits, nuts, eggs, raw milk - all organic if possible. Only dairy should be from grass fed cows and should be raw.
Good luck! I know its easy to get cheap food, but its the cheap food that's the worst for you. Its one area in my life that I'll pay for more now, otherwise we pay a LOT more for it later. Have you priced out cancer lately? It aint cheap!