Monounsaturated and Polyunsaturated Fats

Figure 1. The chemical structure of a triglyceride with a saturated fatty acid (top), a monounsaturated one (middle) and a polyunsaturated one (bottom).

In nutrition, biology, and chemistry, Fat usually means any ester of fatty acids, or a mixture of such compounds, most commonly those that occur in living beings or in food. Fat often refers specifically to triglycerides i.e. the main components of vegetable oils and of fatty tissue in animals. Triglyceride is an ester of the triple alcohol glycerol and three fatty acids. A Monounsaturated fatty acid is a fatty acid (or commonly called Monounsaturated Fat) that has one double bond in its backbone while a Polyunsaturated fatty acid (or commonly called Polyunsaturated Fat) is a fatty acid that has two or more double bonds in its backbone (see Figure 1).

Fats are one of the three main macronutrient groups in human diet, along with carbohydrates and proteins. They are a major and dense source of food energy for many animals and play important structural and metabolic functions, in most living beings, including energy storage, waterproofing, and thermal insulation. The human body can produce the fat it requires from other food ingredients, except for a few essential fatty acids that must be included in the diet (Linoleic Acid and Alpha-Linolenic Acid). Dietary fats are also the carriers of some flavour and aroma ingredients and vitamins that are not water-soluble.

Generally, unsaturated fats, which are liquid at room temperature, are considered beneficial or "good" fats because they can improve blood cholesterol levels, ease inflammation, stabilize heart rhythms, and play a number of other beneficial roles. Saturated fats, such as those found in butter, are usually solid at room temperature. Eating unsaturated fats in place of saturated fats can also help prevent insulin resistance, which is a precursor to diabetes.

Food sources of Monounsaturated Fats include:

• Olive, peanut, and canola oils
• Avocados
• Nuts such as almonds, hazelnuts, and pecans
• Seeds such as pumpkin and sesame seeds

Food sources of Polyunsaturated Fats include: 

• Sunflower, corn, soybean, and flaxseed oils
• Walnuts
• Flaxseeds
• Canola oil