FAT is a word that has a potent impact when used as either a noun or an adjective. I found this post by Deborah Kauffmann, RD, LDN, helpful to have a bit of science to help us understand terminology more rationally and less emotionally.
UNDERSTANDING FAT
Some Fatty Basics
Like carbohydrate, dietary fat is composed of carbon, hydrogen and oxygen. 95% of dietary and body fat is in the form of triglycerides, composed of three fatty acids attached to one glycerol molecule.
There are three types of fatty acids: saturated, monounsaturated and polyunsaturated. This refers to if a fatty acid is saturated with hydrogen atoms along its carbon chain, or if it could hold one more (monounsaturated) or several more (polyunsaturated).
Foods from animal sources contain mostly saturated fatty acids and foods from plant sources contain mostly unsaturated fatty acids.
Fat in the Diet
It is recommended that 20 to 35 percent of each day’s intake should come from fat. Fat provides the most concentrated source of energy for the body. It spares protein from being used for energy so that it can be used to repair and build body tissue. Fat also aids in the transport and absorption of the fat soluble vitamins – A, D, E and K.
Fat also improves the flavor, texture and aroma of foods as well as delaying stomach emptying, helping to create the feeling of satiety after a meal.
“Fattening” Foods
There is no such thing as a “fattening” food. Foods high in fat do not lead to weight gain if eaten when hungry.
During digestion, fatty acids are freed from the glycerol molecule. The glycerol molecule is converted to glucose in the liver, and both fatty acids and glucose are taken up by the cells to provide energy. Fatty acids that are not immediately used for energy are stored temporarily as triglycerides in our fat cells (adipose tissue). In between meals, these are again broken down to fatty acids and glycerol to provide the cells with energy.
We Need Fat
People tend to think it’s best to eat no or very little saturated fat, but the truth is we need all three types of fat. Saturated fat is involved in regulating the expression of several genes, regulating hormones, cell messaging and immune function.
Saturated fatty acids may also help to stop the development of cancer cells and regulate the availability of polyunsaturated fatty acids including omega-3 fatty acids.
Monounsaturated fat and the right balance of omega-6 and omega-3 polyunsaturated fats (4:1 ratio) have been shown to protect the heart, reduce risk of cancer and diabetes, boost the immune system and help with many other medical conditions. Since omega-6 fats are plentiful in our typical diet (most vegetable oils), the focus has been to encourage people to increase intake of omega-3 fatty acids (fatty fish, flaxseed, walnuts) to get the right balance.
About Body Fat
Body fat (adipose tissue) protects vital organs from traumatic injury. Fat is part of every cell membrane and two-thirds of the brain is composed of fat. Fat is a major component of the retina, some hormones and hormone-like substances (prostaglandins), and the myelin sheath that covers our entire nervous system. A layer of subcutaneous fat maintains body temperature. It seems we are always hearing that a higher amount of body fat is unhealthy. Yet that is only true of a higher amount of visceral (deep abdominal) fat which is generally caused by lifestyle factors such as dieting, physical inactivity, stress, alcohol and smoking. In fact, research shows that a higher amount of genetically determined subcutaneous fat is associated with some health benefits – lower risk of heart disease, type 2 diabetes and certain forms of cancer.
I hope this clarifies some of the misunderstanding about dietary and body fat that exists in our culture. Looking forward to your comments and questions in the section below!
CREDITS FOR THIS ARTICLE:
AUTHOR: Deborah Kauffmann, RD, LDN
FROM WEBSITE: More of Me to Love
DIRECT LINK: http://www.moreofmetolove.com/blogs/entry/understanding-fat/
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