At first glance, eating seasonally may seem simple—you eat foods that are "in season," or being grown and harvested at the time of the year when you buy and cook them. That's true, but there's more to it than just being a trendy food movement. There are real benefits to eating foods that are available at their peak right now.
You Can Save a Ton of Money and Eat Better, Healthier Food
Perhaps the biggest tangible benefit of eating seasonally is that you'll save money on food. When you buy what's in season, you buy food that's at the peak of its supply, and costs less to farmers and distribution companies to harvest and get to your grocery store. It may seem like common sense, but it's one of those things many of us ignore when we're shopping.
However, the best consequence of eating seasonally is that you get the best tasting, healthiest food available. The same reasons that keep the cost of seasonal food down also drive its quality up: The food is grown closer to you so it doesn't spoil on its trip, it's harvested at the peak of its season (although there's no real guarantee that it's picked at the peak of freshness), and sold during its season, before it spoils. Ideally, this means you're getting fruits and vegetables that haven't had time to lose their flavor or their health benefits by sitting in a shipping container for a trip across the ocean.
The inverse is true for foods that are out of season. They have to be shipped from around the world to get to you, usually picked before the peak of their flavor in order to survive the long trip (or be allowed to mature while they travel) to your local grocery store. As a result, they're much more expensive because of the time, the distance, and the sheer number of people involved with getting those food items to you that need to be paid.
You End Up Supporting Local, More Sustainable Farmers
Some of these factors can be compounded if you also buy local as well as seasonal. Just because you buy seasonal doesn't mean that a huge food distribution company won't harvest early and keep your food in a warehouse for a while. You'll definitely get better food for less money, but there's no guarantee you'll get food at the peak of freshness, flavor, or nutrition.
If you buy locally, you'll have a better chance at getting foods that are seasonal, fresh, and support local farmers and businesses in your community. Shop at a nearby farmer's market or food co-op, or support a local farm by signing up for a Community Supported Agriculture (CSA) project (or other fresh food delivery service.) Many of those farms and businesses also likely offer organic or sustainable options if you're looking for them. You may wind up spending more to put your money where your taste buds (or personal ethics) are, but it may be a trade-off that's worthwhile to you in the long run.
You Get a Wider Variety of Foods in Your Diet
A pleasant side-effect of eating what's in season is that you get a broader variety of foods in your diet. Those foods can broaden your palate, for one, but they may also expose you to dishes and ingredients you may not have otherwise explored, and while it doesn't go for every location, it can also help you eat a well-rounded and balanced diet as well.
Many of us do this by default to a certain degree—in the spring and summer we eat berries and fruit, then as summer turns to fall we turn our attention to apples, pumpkins, and squash. Part of that is because they're ingrained in our culture, but also because they're seasonal and plentiful. Expanding your horizons a little more can open the door to more delicious food that you can get and prepare cheaply.
How to Tell What's "In Season" Near You
If you're not familiar with what's "seasonal" where you live, it's not too difficult to find out. Take a quick glance around the produce section of your grocery store. Pay attention to the way prices are trending. Have you noticed that berries, peaches, nectarines, and other fruit get really expensive at the end of fall? Or that the ones that are available just don't look as good as the ones during the spring? That's a good indicator. Also, if you notice there's an abundance of something specific, and they're on sale (like potatoes in fall, for example,) that's another good indicator.
Don't Go Overboard
Eating seasonally isn't a new idea, even though it sounds trendy. Michael Pollan discussed the idea in his book The Omnivore's Dilemma several years ago. Before global transportation was as speedy and commonplace as it is today, eating seasonally and locally were just things everyone did. No one assumed you could get peaches in the winter, or chestnuts in the summer. Those things were part of enjoying that season.
Still, like any food movement, don't go overboard with it. There are great benefits, but as soon as your food movement becomes a banner you march under, you lose sight of the benefits. If you can get apples year round and you love apples, enjoy them. If you doctor suggests you get more leafy greens in your diet and kale or collards are out of season but in stock at the store, don't turn them down just to say you're "eating seasonally." That's silly. Just be mindful that you'll spend more in the process and there may be a seasonal or local alternative that's just as good, and good for you.