You're up against a $1.5 trillion industry
Not only is the American food industry massive, it's massively profitable. "Simply put, [Big Food] is the $1.5 trillion industry that grows, rears, slaughters, processes, imports, packages and retails most of the food Americans eat," Pollan writes. This includes four big guns: Big Ag (mostly corn and soybeans), Big Meat, supermarket retailers, and fast-food franchises. So yeah, it's a Goliath.
Much of the industry is controlled by just a few companies
Big Food wields a lot of power as a whole, but the companies within the sectors are even more influential.
"According to one traditional yardstick, an industry is deemed excessively concentrated when the top four companies in it control more than 40 percent of the market. In the case of food and agriculture, that percentage is exceeded in beef slaughter (82 percent of steers and heifers), chicken processing (53 percent), corn and soy processing (roughly 85 percent), pesticides (62 percent) and seeds (58 percent)."