It can be hard to stick to a diet in the winter due to fresh produce being hard to come by. There are actually many fruits and vegetables that are in peak harvest during the winter months. Root veggies are one type that tend to be easy to get in the winter. Turnips are a very healthy form of this. Fennel, Brussels sprouts, and dark leafy greens are also easy to come by in the cold months. If you enjoy fruits more, citrus fruits and pomegranates may be your best choice.