The biggest sources of trans fat are commercially fried foods, packaged baked goods, stick margarine, and vegetable shortening. While a 2018 FDA ban on partially hydrogenated oils removed the vast majority of artificial trans fat from the U.S. food supply, these fats haven’t disappeared entirely. They still occur naturally in some foods, and a labeling loophole means products can claim “0 grams trans fat” while still containing small amounts.
Foods That Still Contain Trans Fat
Before the FDA ban took effect, the agency estimated that 95% of prepared cookies, 100% of crackers, and 80% of frozen breakfast products contained trans fat. Most manufacturers have since reformulated, but the categories worth watching remain the same. If a product was made with partially hydrogenated oil (or imported from a country without similar restrictions), trans fat may still be present in:
- Commercial baked goods: cakes, cookies, pies, and doughnuts
- Fried fast foods: french fries, fried chicken, and other deep-fried items
- Frozen convenience foods: frozen pizza and frozen breakfast sandwiches
- Packaged snacks: microwave popcorn and some crackers
- Refrigerated dough: biscuits, rolls, and pie crusts
- Spreads and fats: stick margarine, vegetable shortening, and nondairy coffee creamer
Stick margarine and shortening historically packed the most trans fat per serving. A single tablespoon of stick margarine contains about 2.8 grams of trans fat, and a tablespoon of vegetable shortening contains roughly 2.4 grams. Tub margarine is significantly lower at about 0.6 grams per tablespoon, because it’s made with less hydrogenation to achieve its softer texture.
The Labeling Loophole to Watch For
Under FDA rules, if a serving of food contains less than 0.5 grams of trans fat, the manufacturer can list “0 g” on the nutrition label. That’s not zero. If you eat multiple servings, or if you consume several of these “zero trans fat” products throughout the day, the amounts add up.
The more reliable check is the ingredient list. If you see “partially hydrogenated” anything (soybean oil, cottonseed oil, palm kernel oil), the product contains some artificial trans fat regardless of what the nutrition panel says. This is the single most useful habit for avoiding hidden trans fat in packaged food.
Natural Trans Fat in Meat and Dairy
Not all trans fat is artificial. Small amounts form naturally in the digestive systems of cows, sheep, and deer, which means beef, lamb, and full-fat dairy products like butter, cheese, and whole milk contain trace levels. Before partially hydrogenated oils were invented, these animal-based sources were the only trans fat humans consumed.
The quantities are small compared to what processed foods once delivered. A glass of whole milk or a serving of beef might contain a fraction of a gram. The FDA has acknowledged that trans fat will never be completely absent from the food supply because of these natural sources. Research on whether natural trans fats carry the same cardiovascular risk as artificial ones is less definitive, but most dietary guidelines treat all trans fat as worth minimizing.
Why Trans Fat Is Worse Than Other Fats
Trans fat has a unique double effect on cholesterol that makes it more harmful than saturated fat. It raises LDL cholesterol (the type that builds up in artery walls) while simultaneously lowering HDL cholesterol (the type that helps clear cholesterol from your bloodstream). Saturated fat raises LDL too, but it doesn’t suppress HDL in the same way. That two-directional hit is why even small amounts of trans fat are strongly linked to heart disease risk.
There is no safe intake level recommended by any major health organization. The goal, as far as nutrition guidelines are concerned, is to eat as little as possible.
Where the U.S. Ban Stands
In 2015, the FDA ruled that partially hydrogenated oils are not safe for use in food. Manufacturers had until June 2018 to stop adding them to most products, with extended deadlines through 2021 for certain items already in the distribution pipeline. The agency also denied a petition from the Grocery Manufacturers Association requesting approval for limited continued uses.
The ban covers artificial trans fat only. It doesn’t affect the naturally occurring trans fat in animal products, and it doesn’t apply to foods imported from countries without equivalent regulations. Restaurant fryers are another area where older practices can linger. Deep-fried foods at restaurants, particularly smaller or independent establishments, may still be cooked in oils that contain trans fat. If you’re trying to minimize exposure when eating out, fried foods and commercial desserts are the highest-risk menu items.
How to Minimize Your Intake
Your most practical tool is the ingredient list, not the nutrition facts panel. Look for “partially hydrogenated” in the ingredients of any packaged food, especially older product lines, store-brand items, and imported goods. Choose tub-style spreads over stick margarine. When cooking at home, liquid oils like olive or canola are naturally free of artificial trans fat.
For the naturally occurring trans fat in meat and dairy, portion control does most of the work. Choosing lean cuts and reduced-fat dairy lowers your exposure without requiring you to eliminate these foods. The amounts are small enough that they rarely approach the levels people were consuming from processed foods before the ban, when the average American ate several grams of artificial trans fat daily.