Fats are energy-providing nutrients that contribute many of the qualities we love about food. The flavor of bacon and butter, the distinctive taste of olive oil, the texture of chocolate and ice cream and the appearance of milk are all thanks to fat. Fats make food easier to chew and induce a feeling of fullness as they take longer to digest. The problem is they are so distinct and appealing that we find it hard to limit our intake. For all their appeal, we know some can raise our cholesterol, increase our risks for heart disease and cancer, as well as contributing to obesity. There are many ways we can change our fat consumption to achieve a healthier outcome, from the products we choose to the way we cook.
The Good: Unsaturated Fats
Formed as liquid at room temperature, Poly and Mono-unsaturated fats are vegetable and fish oils. With the exception of coconut oil, plant oils are healthy and can protect against heart disease and cancer. Classification is based upon composition: Olive and canola oils are classified as mono-unsaturates, while safflower and sunflower are poly-unsaturates. Check out the nutrition facts label on your food products to ensure that the fat you want is that one you are actually getting. These fats are good choices for baking and for use in salad dressings, as well as for frying.
Not every fat is suitable for frying. Use oils with smoke points above 420 deg F to avoid any breakdown of the composition of the oil: This can result in oxidation and the production of free radicals. Vegetable oils used for frying can be re-used up to 3 times, provided it has not changed color, or become thick and dark. Keep the used oil refrigerated to ensure quality is maintained.
Smoke Points of Selected Frying Fats and Oils
|Types of Fat/Oil||Smoke Point (deg F)|
|Vegetable shortenings (Crisco)||356-370|
|Olive oil: Extra Virgin - Virgin||405-420|
The Bad: Saturated Fats
Formed as a solid at room temperature, saturated fats can raise LDL cholesterol and block arteries. These triglycerides are found in steak, sausage, cheese, and butter, these are the fats we try to reduce in our diet to maximize heart health. Not all saturated fats come from animal products as many packaged products use a variety or saturated fats, including palm kernel oil and coconut oil. Again, check the nutrition facts label and the ingredient list to see exactly what you are consuming. While saturated fats don’t influence your HDL cholesterol (the good one), replacing them with unsaturated fats is a heart-healthy choice. Reducing your intake can be achieved by choosing lean cuts of meat, using vegetable-based spreads and buying reduced fat products.
The Ugly: Trans Fats
Trans fat is formed when a liquid vegetable oil (usually a good fat) has hydrogen added to change its chemical composition. This change alters the shape of the fat and makes it more solid, so food manufacturers use it to lengthen the shelf life of their products. It raises LDL cholesterol, and it may also lower HDL cholesterol: People who eat more trans fats are at greater risk for heart disease. The list of ingredients on your food product might not list any known saturated fats, however, trans fats must now be listed on the label so make sure you check it out.
Tips for Limiting Trans Fats
1. Choose foods low in both trans fats and saturated fats.
2. The ingredients list must disclose ‘partially hydrogenated’ oil. This is a trans fat.
3. Federal regulations do not require foods with less than 0.5g/serve of trans fat to be listed. However, if you are eating more than one serving you are exceeding this amount.
4. Avoid choosing food because it has been labeled ‘trans fat-free’. Read the nutrition facts label to see how much saturated fat the food has. A product with 6 g of saturated fat and no trans fat raises your LDL as much as a product that has 3g saturated fat and 3 g trans fat.
5. Look for sandwich spreads with less than 2g of saturated and trans fat per serving. Choose a margarine that is in a tub or is liquid as it will have a higher concentration of vegetable oils
6. Cookies, doughnuts, some crackers, and snack products use partially hydrogenated vegetable oils to extend shelf life. Be careful if purchasing these.
7. Intake of saturated and trans fats should be below 7% of your total calories.
Lisa Wingrove, RD, CSO, is a registered dietitian and a board-certified specialist in oncology at the CU Anschutz Health and Wellness Center. She is involved in projects to improve patient outcomes and education, including our Culinary Medicine Program, an evidence-based field in medicine that blends the art of food and cooking with the science of medicine.