In Part One of the Fats Series, we showed you what a fat is and explained the roles that fats play in your body. In subsequent parts, we will take a look at the different types of fats that we ingest, what differentiates them from other fats and the effects that each have on your health. Part Two deals with unsaturated fats.
As we pointed out in Part One, unsaturated fats have open spots on the carbon chain and aren’t completely “saturated” with hydrogen. Due to the open spots, double bonds form on the carbon chain. Unsaturated fats are classified into two categories, based on the number of double bonds on the chain. A “mono-unsaturated fat” only has one double bond, whereas a “poly-unsaturated fat” has multiple double bonds. Since double bonds are less stable than the carbon-hydrogen bonds, unsaturated fats have a lower boiling point relative to saturated fats and are liquid at room temperature. Since the majority of unsaturated fats are found in vegetables, unsaturated fats have come to be known by many as “vegetable oils,” although they can also be found in nuts, seeds, fish and some fruits. Common sources of mono-unsaturated fat include olive, peanut, canola and avocado oils. Poly-unsaturated fat sources include safflower, sesame, corn and soybean oils.
Unsaturated fats are the most common source of fat you will find in most people’s diets. They are a great source of energy, providing around nine calories per gram and they typically provide good benefits for your cholesterol levels. Most unsaturated fats help to reduce LDL (bad) cholesterol while maintaining your HDL (good) cholesterol. The impact of the oil on your health can be drastically changed if the oil is hydrogenated, thereby turned into a “trans” fat, but we will cover those later. Their liquid form and generally high heat tolerance make oils ideal for cooking.
The biggest problem you will encounter with unsaturated fats has to do with their stability, or lack thereof. Unsaturated fats go rancid and oxidate very easily, losing their nutritional value and taste. Antioxidants can help to prevent oxidation, and proper storage techniques can also help to postpone shelf life, but if oils are not taken care of properly they can go bad very quickly.
Since fats are so calorie rich, they have become a topic of great controversy and everyone has an opinion on how much you should consume. Barry Sear’s (creator of the Zone Diet) and the FDA believe that you shouldn’t get more the 30 percent of your daily caloric intake from fats. This has become a popular benchmark in the industry and has been used in other places as well such as the Food Pyramid and even Atkin’s Diet, but this number is sort of arbitrary. It’s up for debate how dietary fat consumption truly affects fat storage and lypogenesis in your body, but it’s a complicated picture that depends on a lot of other factors. These factors include carbohydrate intake, family history and genetic predisposition to cholesterol along with a host of other variables.
As long as unsaturated fats aren’t hydrogenated, they comprise an extremely valuable source of energy and should be a huge component of your diet. In Part Three, we will look at Saturated Fats and the heap of controversy they are associated with.
Nuwanee Kirihennedige – Is a nutritionist and dietician that works with athletes and health minded individuals on sports performance and weight loss. Nuwanee currently is the nutritionist for the California Strength Academy in San Ramon California. Nuwanee can be reached at nuwanee@californiastrength.com.