All fat is composed of different fatty acids. There are saturated, monounsaturated and polyunsaturated types. The kinds of fatty acids consumed are more important in influencing health than the total amount of fat in the diet. Animal fats tend to have a higher proportion of saturated fatty acids (seafood being the major exception), and plant foods tend to have a higher proportion of monounsaturated and/or polyunsaturated fatty acids (tropical oils being the exception).
Saturated fats tend to be solid at room temperature. Think of the fat in meat, poultry, butter, or cheese. Whole, 2%, and 1% milk also contain saturated fatty acids. Tropical oils are solid at room temperature because they contain high amounts of saturated fatty acids.
The primary sources of saturated fat are cheese, pizza, desserts, chicken, and processed red meat like sausage and ribs. Saturated fats increase the risk of cardiovascular disease, and according to the Dietary Guidelines for Americans, they should be used in small amounts and replaced by foods higher in monounsaturated and polyunsaturated fatty acids to promote cardiovascular health.
Monounsaturated and polyunsaturated fats are usually liquid at room temperature and are found in seafood, nuts, seeds, avocados, olives, and liquid oils. The difference between monounsaturated and polyunsaturated fats is in the number of double bonds in their chemical make-up. Oils high in monounsaturated fatty acids include canola, olive, peanut, sesame, and safflower oils. Oils that are good sources of polyunsaturated fatty acids include soybean, corn, and cottonseed oils. Replacing foods high in saturated fats with foods high in monounsaturated or polyunsaturated fatty acids helps decrease risk of cardiovascular disease.
Trans fatty acids are the worst type of fat for our health. The bulk of our trans fatty acid intake comes from processed foods such as partially hydrogenated oils used in some margarines, snack foods, and prepared desserts. Trans fats from partially hydrogenated oils raise LDL cholesterol levels and lower HDL cholesterol levels, increasing risk of heart disease and stroke.
The Dietary Guidelines recommend acceptable ranges for total fat intake to reduce risk of chronic disease such as cardiovascular disease, while promoting optimum intake of essential nutrients. Keep trans fatty acid intake as low as possible, and choose foods higher in monounsaturated and polyunsaturated fatty acids to replace foods with saturated fatty acids.
Here are the overall fat intake recommendations:
- 30-40% of total calorie intake for children ages 1-3 years
- 25-35% of total calorie intake for children and teens ages 4-18 years
- 20-35% of total calorie intake for adults age 19 and over
By Lynn Grieger RDN, CDE, CPT, CWC
- Dietary Guidelines for Americans 2010. http://health.gov/dietaryguidelines/dga2010/DietaryGuidelines2010.pdf.
- Fat 101. American Heart Association. http://www.heart.org/HEARTORG/GettingHealthy/FatsAndOils/Fats-101_UCM_304494_Article.jsp#.VkpG_3arT9g
- Trans Fats. American Heart Association. http://www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/HealthyEating/Trans-Fats_UCM_301120_Article.jsp#.VlkAzHarT9g
Stephanie Ronco has been editing in a professional capacity for the past 10 years. In addition to her work as an editor, Ronco has also served as a ghostwriter and writing tutor. A voracious reader, Ronco loves watching language evolve and change. When she’s not delving into her latest project, Ronco can be found teaching acting classes, performing in community theater, or sailing with her husband.