To save time, choose frozen vegetables over canned to get the most nutrition in a quick, low calorie meal.
When vegetables are in-season, buy them fresh and ripe. “Off-season,” frozen vegetables will give you a high concentration of nutrients. Choose packages marked with a USDA “U.S. Fancy” shield, which designates produce of the best size, shape and color; vegetables of this standard also tend to be more nutrient-rich than the lower grades “U.S. No. 1” or “U.S. No. 2.” Eat them soon after purchase: over many months, nutrients in frozen vegetables do inevitably degrade. Finally, steam or microwave rather than boil your produce to minimize the loss of water-soluble vitamins.
Also, avoid canned vegetables since the canning process destroys much of the water-soluble vitamins in most veggies. The exception are tomato products, which actually increase in cancer killing compounds when canned, then cooked.
