By LIZ HAGERMANNLEANOTEM, Associated PressWASHINGTON (AP) When it comes to plant-derived proteins, it’s all about the healthiest option: vegetable gardens.The key, say many plant-protein advocates, is to avoid high-protein foods, such as white potatoes, beans, corn and lentils, which contain a lot of protein but are high in fat.That’s not the case for meats, dairy …