Approximately 10% of the produce food banks receive comes from farms. Nationwide, Feeding America reported that in 2017, they received 1.47 billion pounds of produce from all of their sources, including grocery stores, distributors, and farms. We reached out to Feeding America and they clarified that only about 10% of this 1.47 billion pounds comes from farms--roughly 147 million pounds.
This 147 million pounds is the closest national figure available, but some food banks aren’t in Feeding America’s network so the total number is likely a bit bigger. Given the amounts of produce other organizations recovered in 2017, the full number for what all non-profits recovered from farms in 2017 is in the range of 200-400 million pounds. Meanwhile, Feeding America estimates that 50-100 times that much -- a total of 20 billion pounds -- is still going to waste on farms each year.
The root of the problem of hunger is not supply, but distribution. As Feeding America has said, America grows enough food to feed everyone but due to the massive amount of waste in this country we still have 40 million Americans struggling with hunger.