Which type of fat is considered unhealthy and should be limited in the diet?

Trans fats are considered unhealthy and should be limited in the diet due to their negative impact on heart health. These artificially created fats are formed through the process of hydrogenation, which solidifies liquid oils, making them more stable and shelf-stable for use in processed foods. The consumption of trans fats has been associated with an increase in low-density lipoprotein (LDL) cholesterol levels—commonly known as "bad" cholesterol—while simultaneously lowering high-density lipoprotein (HDL) cholesterol levels, which is known as "good" cholesterol. This imbalance contributes to a higher risk of heart disease, stroke, and other cardiovascular conditions.

In contrast, unsaturated fats, including both monounsaturated and polyunsaturated types, are considered to be beneficial for health when consumed in moderation. These fats can help to improve cholesterol levels and provide essential fatty acids the body needs. Omega-3 fatty acids, a subgroup of polyunsaturated fats often found in fish and flaxseeds, have been shown to have anti-inflammatory properties and are protective against heart disease. Thus, limiting trans fats is crucial for maintaining cardiovascular health, making it important to identify and restrict their intake in the diet.