What is Saturated Fat?

By Megan Holt, DrPH, MPH, RD

Question: I’ve been hearing a lot about saturated and unsaturated fat in the news lately.  What’s the difference between them? And what about monounsaturated and polyunsaturated fat?

Fats, both saturated fat and unsaturated fat, and their effects on health are regularly a favorite topic of the media.  As new research comes out about these two types of dietary fat, it’s good to become familiar with saturated fatty acids and how they differ from poly or monounsaturated fatty acids:

Saturated fatty acids (SFAs), what we generally refer to as saturated fat, have the following characteristics distinguishing them from other fatty acids (trans-fat, monounsaturated fat and polyunsaturated fat):

  • Solid at room temperature
  • Occur naturally in foods
  • Referred to as ‘saturated’ due to their having no double bonds along the carbon chains that comprise these saturated fatty acids

On the other hand, unsaturated oils, otherwise known as unsaturated fat, are:

  • Liquid at room temperature
  • Primarily found in higher concentrations in plant sources (with the exception of fatty fish)
  • Have one (mono) or multiple (poly) double bonds along the carbon chain

Contrary to popular belief, foods do not consist of only one type of fatty acid. Rather, foods are composed of varying percentages of unsaturated and saturated fatty acids.  For example, SFAs comprise roughly 13% of the fatty acids in olive oil and 65% of the SFAs in butter.  SFAs are found in higher amounts in dairy products (ex: cream, butter, milk, cheese) as well as in meats (bacon, sausage, chicken fat, mutton), ghee, suet and lard.  Palm oil, palm kernel, coconut and cottonseed oils contain a larger percentage of SFAs (relative to the other plant based fats), though they lack the cholesterol contained in animal sources. 

When making healthy choices at restaurants, check total fat, saturated fat and unsaturated fat in the available nutrition information.  Healthy Dining menu choices are carefully selected by registered dietitians based on strict criteria (including total fat and saturated fat) to make finding the best choices at restaurants easy.