There's a reason you're confused in the butter aisle. Years ago, butter was a no-no. Vegetable-oil-based margarines surged in popularity as doctors began to understand the dangers of saturated fat. But the butter-versus-margarine debate is a slippery subject. Some margarines have unhealthy trans fats, while others have confusing health claims. Meanwhile, some say butter is an "all-natural" choice. Well, we've got the bottom line on butter and its alternatives. Here are some of the best and worst products for your heart. What experts say The American Heart Association suggests buying soft, trans-fat-free spreads instead of regular butter or stick margarine. Choose a blend with the least amount of saturated fat and zero trans fats. Check the ingredients: If it says partially hydrogenated oils, it still has some trans fat (less than 0.5 gram per serving), even if the label says trans fat free. These can add up if you have more than one serving. If you like butter better... Regular butter is made with one ingredient: cow's milk or cream, churned or shaken until it reaches a semisolid state. By definition, it contains at least 80% milk fat by weight, and it takes about 11 quarts of milk to make 1 pound of butter. Traditionally, butter comes in salted and unsalted varieties, and it can be found in solid stick form or whipped and packaged in plastic tubs. You may also find cultured butter, a rich butter made from cultured cream popular in Europe, at your grocery store or specialty foods store. Worst butter: Traditional sticks Most "original" butter sticks contain 100 calories per tablespoon, a typical serving size. One serving has 11 grams of fat, and 7 grams of it is artery-clogging saturated fat—about one-third of your recommended daily value! It also contains 30 milligrams of dietary cholesterol (10% of your daily value). Some have even more fat; Ireland's Kerrygold Unsalted Pure Irish Butter, for example, contains 12 grams of fat, 8 grams of it saturated. If you see terms like "rich," "cultured," or "European style" (or if it's made in Europe), check the label. Better: Whipped butter The process of whipping adds air to the butter, making it lighter and less dense. If you can stick with the same tablespoon-size portion, you'll save up to half the calories and saturated fat by choosing whipped butter in a tub. Land O'Lakes Whipped Butter, for example, contains 50 calories and 6 grams of fat (3.5 grams saturated), and only 15 milligrams of cholesterol per serving. You can also choose an organic brand like Organic Valley Whipped Butter. Better: Light butter If you still prefer a stick over a tub, light or low-fat butter is a smart choice. It's made with added water or gelatin (and preservatives) to give it a solid consistency, and it generally has half the fat and calories as traditional butter. A serving of Land O'Lakes Light Butter, for example, has only 50 calories and 6 grams of fat (3.5 grams saturated). Just don't use twice as much to make up for any difference in flavor, says Janice Baker, RD, a nutritionist and certified diabetes educator. Better: Vegetable-oil blends A butter blend with added olive or canola oil won't cut calories or fat much or at all—most have 100 calories and 11 fat grams per serving—but it will lower saturated fat and cholesterol. What's more, these are typically softer and easier to spread right out of the refrigerator. To lower calories, select a "whipped" or a "light" blend. We like Shedd's Spread Country Crock Spreadable Butter with Canola Oil (80 calories and 9 grams of fat, 3.5 saturated), and Land O'Lakes Light Butter with Canola Oil (50 calories and 5 grams of fat, 2 saturated). What is margarine? Developed in the 1800s in France when butter was scarce and expensive, margarine has had its ups and downs, including several U.S. bans and taxes driven by the dairy industry. It's been called a healthier, plant-based alternative to butter, but it also faced a backlash for being artificial and having trans fats, which help keep oil-based ingredients solid at room temperature. Margarine is any vegetable-oil-based, butter-flavored spread that contains 80% oil; anything with a lower oil and fat content is called a "soft margarine spread." Worst margarine: Sticks with trans fat To stay solid at room temperature, vegetable oils are hydrogenated, which creates trans fatty acids that can raise LDL, or bad cholesterol. Most solid sticks of margarine contain trans fats and/or saturated fat. These include Country Crock Spreadable Sticks (80 calories, 1.5 grams saturated fat, 2 grams trans fats), Blue Bonnet Sticks (70 calories, 1.5 grams saturated fat, 1.5 grams trans fat), Land O'Lakes Margarine Sticks (100 calories, 2 grams saturated fat, 2.5 grams trans fats), and Fleischmann's Original Stick Margarine (80 calories, 2 grams saturated fat, 1.5 grams trans fat). Better: Trans-fat-free sticks A gram or two of trans fats may not seem like a lot, but even small amounts are bad for the heart. Baker recommends keeping trans-fat intake as low as possible. There are trans-fat-free options if you need hard butter or margarine for baking. Promise Sticks contain 80 calories per serving, and 9 grams of fat (2.5 grams saturated). I Can't Believe It's Not Butter Sticks and Earth Balance Vegan Buttery Spreads contain no trans fats, but they still have 3.5 grams and 4.5 grams of saturated fat, respectively, and the same amount of total fat and calories as butter. Better: Soft spreads Soft spreads packaged in a tub are generally much healthier for your heart, because they contain less saturated fat and many are trans fat free. Some examples include Fleischmann's Original Whipped Tub with 60 calories and 7 grams of fat (1 gram saturated) per serving, Smart Balance Original Buttery Spread with 80 calories and 9 grams of fat (2.5 grams saturated), and Blue Bonnet Soft Spread with 60 calories and 6 grams of fat (1 gram saturated). These spreads work best for cooking, on bread, or with vegetables; however, they're not recommended for baking, says Baker. Better: Light or fat-free spreads Just as with butter, light or low-fat usually means that a spread has added water or fillers to reduce the overall fat and calorie count. Several major brands offer a light product, such as Blue Bonnet Light Soft Spread (40 calories, 4.5 grams fat, 1 gram saturated fat) and Smart Balance Light Original Spread (50 calories, 5 grams fat, 1.5 grams saturated fat). Whipped spreads, like Shedd's Spread Country Crock Churn Style (60 calories, 7 grams fat, 2 grams saturated fat), will generally have less fat and fewer calories than a denser original style. Better: Butter-substitute sprays You can also find butter substitutes in liquid form: I Can't Believe It's Not Butter Spray and Parkay Spray both offer a hint of buttery flavor with very little fat and no cholesterol. One serving is listed as having 0 calories and fat, although in reality there are tiny amounts of each—so you can still overdo it! These are good options for flavoring vegetables, potatoes, and poultry, but might make your bread a bit soggy. Toss-up: Fortified spreads There are spreads with add-ins: cinnamon or garlic-and-herb flavoring, calcium and vitamin D, omega-3s and flax oil, and those touting "the wholesome goodness" of natural yogurt or extra-virgin olive oil. In reality, a serving of butter or margarine should be so small—just a thin spread—that you won't get that much nutritionally out of the products, says Baker. Instead, check the label, including the calories per tablespoon, total fat, saturated fat, and trans fats, to make a smart choice that fits your taste and budget. Toss-up: Plant sterols Products like Benecol, Promise Activ, and Smart Balance HeartRight contain plant sterols and omega-3 fatty acids that have been shown to reduce LDL levels when eaten as part of a healthy diet. There's nothing wrong with these products, says Baker. But they tend to be expensive, she says, and relative to other diet and lifestyle changes a person can make, eating enough of these products to make a difference in your cholesterol seems like a stretch. Look at the big picture for greater impact on heart health: Eat fewer saturated and trans fats, consume more plant-based foods, and get enough exercise. Healthier options Your healthiest option may be to skip both the butter and the margarine. Baker recommends using monounsaturated fat instead: olive oil for dipping bread or vegetable oil for cooking. "If you love the taste of butter and you want to sauté some mushrooms in it, I'm not going to say you can't do it, but maybe try using a little less butter and a little more oil." Use avocado and nut butters in place of butter on sandwiches, she says. "That way you're getting fat intake but it's healthy fat intake." (Calories from any source of fat add up quickly, though, so be conscious of your portion sizes as well.) Don't overdo it Whatever product you select, limit your consumption overall. When baking, use a hard stick of trans-fat-free margarine in place of butter. Regardless of what you use, portion size is key. "If you use a whole stick of butter when making a tray of brownies, it's not a big deal," says Baker. "As long as you eat only one or two brownies."