Trans fats are artificially created fats found in some processed foods that can increase LDL cholesterol levels while decreasing HDL cholesterol. This combination significantly raises the risk of heart disease and stroke. Common sources include fried foods, baked goods, and margarine. Due to their harmful effects on health, many countries have imposed bans or strict regulations on their use. To promote wellbeing, it's recommended to limit or eliminate trans fat consumption, opting for healthier fat sources like olive oil and avocados instead.