The type of fat considered unhealthy and should be limited is saturated fat and trans fat. Saturated fats, found in animal products like red meat and full-fat dairy, can raise cholesterol levels and increase the risk of heart disease. Trans fats, prevalent in processed foods, snacks, and some margarines, are particularly harmful as they raise LDL cholesterol while lowering HDL cholesterol. Limiting intake of these unhealthy fats favors better heart health and overall wellness.