Trans fats arise in two ways. Industrial trans fats are created by partially hydrogenating liquid vegetable oils to make them solid and shelf-stable — found historically in margarine, commercial baked goods, fried fast foods, and vanaspati. Ruminant trans fats occur naturally in small amounts in dairy and meat from cattle and sheep; evidence suggests these are not harmful at typical dietary levels.
Industrial trans fats are unambiguously harmful. Even at 1–2% of energy intake, they raise LDL, lower HDL, promote inflammation, and increase heart disease risk substantially. The WHO’s elimination target was 2023; India’s FSSAI limits trans fats in oils and fats to ≤2% since 2022.
Read ingredient labels: “partially hydrogenated oil” anywhere in a product signals industrial trans fats. Many reformulated products have replaced trans fats with saturated fats — an improvement, but not a free pass. Choose products with the shortest, most recognisable ingredient lists.