U.S dietary guidelines suggest making half your meal fruits and vegetables, but that can be costly. Nicole Patience, a registered dietitian at Temple, says frozen vegetables can be a low-cost alternative to fresh ones. "Frozen vegetables work very well, or you might choose fresh vegetables that have a longer shelf life that aren't going to go bad in two or three days — things that are a little sturdier like celery or a fruit such as apples," she said.