Interestingly enough, the United States actually ships out a wide variety of produce as well. Tree nuts produced in the United States are exported at a rate of over 50%. That means more than half of all grown pistachios, almonds, walnuts and etc are shipped abroad. - USDA
With more nuanced regulations and better quality oversight, the United States can produce relatively healthy, quality produce to export. However, what about the food being imported? This is a challenging question to fully answer. Obviously, with some of the lower-standard regulations abroad, the quality of imported food could be considered less than that of its domestic counterparts. To help ensure our safety, the United States has various regulations and inspection requirements for imported goods. With the sheer volume though of imported foods these inspections could have various loopholes and faults. Regardless, the government continues to try to maintain the quality of food and develop better protocols to do so. This is important given the scope - The Pathway to Global Product Safety and Quality has these numbers. With statistics like this it's easy to see how the future of aquaponics and hydroponics could greatly increase domestic output and confidence in overall quality.
- Around 10-15% of all food in the US is imported
- Nearly 2/3 of fruits and veggies are imports
- 80% of seafood
So that's where our fruits and veggies come from. Largely abroad, unless you're talking about nuts, lettuce, corn, or soybeans.