“The US Department of Agriculture estimates that more than 20 million victory gardens were planted. Fruit and vegetables harvested in these home and community plots was estimated to be 9-10 million tons, an amount equal to all commercial production of fresh vegetables.” https://livinghistoryfarm.org/farminginthe40s/crops_02.html
That’s 3 pounds per person per week, or 1/3 of the total 12lb of vegetables per person consumed per week.
Once again, this is a facially stupid claim. If you know anything about industrial agriculture, it's clearly impossible. Where are you reading this?
My guess is you're being confused by the "fresh" qualifier, which is probably the intention.