Trans fats are the type of fat most clearly linked to negative effects on heart health, followed closely by saturated fats when eaten in excess.

Quick Scoop

  • Trans fats (often listed as “partially hydrogenated oils”) are considered the worst for heart health because they raise LDL (“bad”) cholesterol and lower HDL (“good”) cholesterol, which increases the risk of heart attack and stroke.
  • Trans fats are commonly found in some fried foods and older-style commercial baked goods, which is why many countries have moved to restrict or ban them.
  • Saturated fats , found in fatty meats and high‑fat dairy, can also raise LDL cholesterol and may increase cardiovascular risk when consumed in high amounts, especially compared with unsaturated fats.

Bottom line: The type of fat that may most negatively impact heart health is trans fat , with high intakes of saturated fat also contributing to increased heart disease risk.