Processed food ingredients in the US are highly subsidized by the US government. The resulting processed foodstuffs are shelf stable, widely distributed, and trounce local options in the market place through sheer scale. More often than not, "real food" == "health food" == "luxury item". It's unfortunate and unhealthy.
The government subsidizes the crops used in processed foods, specifically corn, soybeans, wheat, sugar crops.
But these crops also supply animal feed, fuel, exports, and ordinary foods.