How can you tell if the product you’re buying in the grocery is actually as healthy as it claims to be? In this age of massive marketing gimmickry, it pays to be well informed.

A few days ago, Cleveland Clinic, a multispecialty academic hospital in Cleveland, Ohio, and consistently among the top five hospitals in the United States, released these useful guidelines to help you do your groceries.

Learn how to read the labels with a discerning eye. It’s no rocket science and it’s simpler than you think.

1) The fewer the ingredients, the better. That means no more than five ingredients on the label. A long list of ingredients means the food is highly processed.

And these ingredients must be “real,” too, with names you recognize, like chicken or banana. If it reads like a Latin phrase, chances are, that’s not real food.

Also, don’t stuff yourself with ingredients that read like a chemistry experiment, such as maltodextrin, Polysorbate 80 or butylated hydroxytoluene, or blue or red dyes. If these are ingredients you don’t find in your cupboard, don’t buy the product.

2) The more claims a product makes, the less healthy it might be. Cleveland Clinic reported that according to research, the least healthy food are advertised the most heavily. Be wary if you see five claims, the report said.

Take those whole-grain oats that “help reduce cholesterol,” are “heart-healthy,” “gluten-free,” “100-percent whole grain,” “no artificial flavors or colors.” Check the other main ingredients and you’ll find sugar and cornstarch. A single, one-cup serving contains 20 grams of carbs.

‘Heart-friendly’

How about cereals labeled “heart-friendly?” They may be low in fat, but they’re high in sugar and starch. Added sugar has been proven in recent years as the main culprit in raising heart disease risk, not dietary fat. Yet these products are still labeled “heart-friendly.”

Besides, 1 g of soluble fiber per serving, the Cleveland Clinic report said, is not enough to lower your cholesterol.

3) Frozen may be better than fresh. We may think fresh fruits and vegetables are more nutritious, but frozen food are picked at the point of “pure ripeness” in the peak of the season, and then flash-frozen. Their nutrients won’t degrade—that’s why you won’t find mold growing on them.

True, a frozen vegetable may not taste as good as the fresh produce picked from your pocket garden, but here’s where frozen vegetables have the edge—they haven’t been transported long distances, like the fresh veggies in the groceries. It is less likely to have degraded nutrients. Even better, frozen is cheaper than organic fruits and vegetables.

Don’t pick the next can of fruits or vegetables you see, though, since they often contain added sugar or salt. That would be your least nutritious option. Produce canned or jarred in their whole form is fine, Cleveland Clinic said. Just make sure the cans are BPA-free.

4) “Not all man-made products are bad, but you want your food to be as close as possible to its original,” the report said. Bottled tomatoes in water and salt are fine, as are bottled sardines in olive oil or salt. The test, the report said, is to cover the label with your hand and read the ingredients list. If you can still recognize what it is, that should be fine.

Red flags are if it contains a super-long list of ingredients, or if it comes in weird shapes or colors.