Let's Talk About Fats

Submitted by: Jessica Ball

Edited by: Marcia Bristow MS RDN CSSD CD

Fats have always been a controversial topic, even though everyone needs dietary fats to survive. Fat in our body is more than just stored calories; it is in the membranes of each of our cells. Even our nerves need fats to be healthy!¹ There are two main types of fats in the foods that we eat: unsaturated and saturated fats. Each has a separate effect on how fat is utilized in our body.

Fat is carried through the bloodstream by two different types of cholesterol: high-density lipoproteins (HDLs) and low-density lipoproteins (LDLs). LDLs are messier in their delivery of fats. Their spilling contributes to fatty buildup and narrowing of your arteries, increasing your risk of heart disease.² However, this excess fat from LDLs is cleaned up and brought to the liver by HDLs. This reduces the possibility of buildup in your arteries and chance of chronic illness.²

Unsaturated fats are typically liquid at room temperature and include olive and canola oil. Also, nuts, avocados and fish oils are nutrient-dense sources of unsaturated fats. Including these types of fat in your diet increases HDLs and lowers LDLs in your blood, which has been shown to reduce risk of heart disease.^3.4 Saturated fats are easy to identify because they are typically solid at room temperature. Meat, dairy and other animal products contain saturated fats. However, not all saturated fats are found in animal products. For example, palm oil and coconut oil are plant sources of saturated fats. It is important to limit consumption of these kinds of fats because they may decrease HDLs and increase LDLs in your blood and ultimately contribute to heart disease.³

Coconut oil, a plant source, has 50% more saturated fat than butter.⁵ So what’s all the fuss about coconut oil if it has such a high amount of saturated fat? Some recent studies have found that coconut oil is less efficient to digest than other fats, so it might promote the rate at which you burn calories and contribute to fullness. This may slightly promote weight loss, but the majority of studies are done on animals so the effect on humans is unclear.⁵ Coconut oil may increase HDLs, like unsaturated fats, and also increase LDLs, similar to saturated fats.⁵

Here’s the bottom line: eat more of the high-quality unsaturated fats, such as nuts, seeds, oils, fish and avocados. Moderate your intake of coconut oil, full-fat dairy, unprocessed meats and other saturated fats.

References:

1.     Harvard Health Publishing. The truth about fats: the good, the bad, and the in-between - Harvard Health. Harvard Health Blog. https://www.health.harvard.edu/staying-healthy/the-truth-about-fats-bad-and-good. Accessed May 8, 2018.

2.     HDL (good), LDL (bad) cholesterol and triglycerides. American Heart Association. http://www.heart.org/HEARTORG/Conditions/Cholesterol/HDLLDLTriglycerides/HDL-Good-LDL-Bad-Cholesterol-and-Triglycerides_UCM_305561_Article.jsp. Accessed February 16, 2018.

3.     Willett WC. Dietary fats and coronary heart disease. J Intern Med 2012;272(1):13-24.

4.     Willett WC. The Mediterranean diet: science and practice. Public Health Nutr 2006;9(1a).

5.     Coconut oil – what's behind the “health halo”. Today's Dietitian. http://www.todaysdietitian.com/newarchives/1016p32.shtml. Accessed February 16, 2018.