You already know that vegetables are a good source of fibre, antioxidants, vitamins, and minerals that boost your performance and recovery, so you load up your trolley with a bunch of fresh produce. But when you round the corner and spot the freezer aisle, you wonder: Are frozen vegetables healthy?

It’s a fair question, especially if you’ve bought a bunch of greens with the intention of eating more salad, but three days later, you’re forced to toss the wilted leaves and hard-earned cash in the trash (been there). Or you’re stocking up on frozen options during the pandemic to limit visits to the grocery store.

The good news: Vegetables are often harvested and then immediately frozen, which helps them retain their nutrition profile, says Lindsey Pfau, M.S., R.D., C.S.S.D., and owner of Rise Up Nutrition. “Most companies freeze their vegetables within hours,” she says. “And their nutrition wouldn’t really suffer even if they’re not frozen for a few days.”

As athletes, we all have busy schedules—work, train, family, eat healthy, repeat—which can make it difficult to prep and cook fresh veggies all of the time. (Pre-cut fresh veggies are a heck of a lot more expensive than frozen, too.) So buying frozen vegetables makes it easy to prepare a healthy meal. The veggies are already cut, and all you need to do is thaw, cook, and toss with a protein and grain.

Not to mention, in general, frozen vegetables are cheaper than fresh, so if you’re on a budget, frozen is a good option, says Pfau. All that said, there are a few things to watch out for. Here’s what you need to know about keeping frozen vegetables healthy.

Cooking Method Matters

When you grab that bag of broccoli and start preparing dinner, boiling runs the risk of leeching the nutrients out of your vegetables, says Pfau. The same goes with fresh veggies, she says.

Water-soluble nutrients—B vitamins, including folate, and vitamin C—are the ones most affected by boiling. You could lose up to 75 percent of these vitamins by cooking them that way. Steaming is a slightly better option, but you still could lose a chunk of those water-soluble nutrients due to the amount of water needed to steam, says Pfau.

Instead, Pfau recommends sautéing frozen and thawed vegetables with olive oil, or blanching, roasting, or baking them. Pro tip: When you sauté, don’t toss the oil. Any nutrients that cook out can still be salvaged when you use the oil in your dish.

Choose Your Frozen Produce Wisely

A 2015 study published in the Journal of Agricultural and Food Chemistry found that the nutritional content of some fruits and vegetables are more affected by the freezing method than others.

For example, riboflavin, a B vitamin that helps with cell growth and function, was lower in frozen peas (versus its fresh counterparts) but was higher in frozen broccoli. Vitamin E was higher in frozen peas, green beans, spinach, and corn. Magnesium, which is crucial for muscle health, was slightly lower in frozen peas, spinach, and corn. Iron, which carries oxygen to the muscles, was lower in frozen spinach and carrots, which is important to note as endurance athletes like cyclists are at a higher risk of being iron-deficient thanks to the toll training can take.

Avoid Sauces and Other Additives

One of the downsides to going frozen is falling into the trap of prepackaged sauces, says Pfau. “I recommend getting just the frozen vegetable or a blend of vegetables, and avoiding flavourings,” she says. Packaged seasoning and sauces are often high in sugar and sodium. Instead, flavour your veggies yourself with spices and herbs like chili pepper, cumin, salt and pepper.

The bottom line: Frozen vegetables are an excellent option when you’re short on time, on a budget, or you just prefer the convenience. Generally speaking, the freezing process won’t disturb a vegetable’s nutrient content, so long as you take care with your cooking method.

Some people, Pfau points out, think eating raw veggies is best. And just by the nature of using frozen produce, you aren’t going to eat raw. “But balance and variety are good,” she says. “Yes, you might lose some water-soluble vitamins and antioxidants in heating, but some antioxidants and enzymes are activated and enhanced through cooking.” So mixing in fresh, raw veggies with frozen vegetables that you consume often but that go bad quickly is the best, balanced approach.

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