I think I asked the million dollar question!
Are you trying to lose weight? It seems like everyone is, almost 90% of the population want to lose some weight, maybe only 5 or 10 pounds, or maybe 50 or even 100 pounds. And we want the results to come as fast as possible — even though we didn’t gain all of the weight so quickly, we want to lose it quickly. And I understand that, it would be really nice to lose weight quickly.
Actually it is possible to lose weight quickly too, however if you do not heal the cause of the problem that made you get fat, then you will not sustain any weight loss.
So what are our options for sustainable fat loss? First, we need to know how the body burns fat, and what fat really is.
Lipids (fats) are composed of carbon (C), hydrogen (H), and oxygen (O). They have much more carbon and hydrogen in relation to the oxygen, so they can supply more energy per gram than carbohydrates. In fact, one gram of carbohydrate provides 4 calories of energy, while one gram of fat provides 9 calories. So fat is an extremely efficient storage form of energy in the body.
To “burn” fat, first the body needs to get it out of the fat cells, break it down, transport it, and oxidize it. When the body then oxidizes (burns) the fat with oxygen, it produces energy in the form of adenosine triphosphate (ATP).
ATP is the only fuel that our body’s cells can use directly. It is like the basic energy currency of all cells in the body — other fuels, apart from fat, are only valuable when they can be oxidized to produce ATP.
The fat cells in our body — either from food or from the body’s fat stores — readily take up and store triglycerides. Almost all fat in our diet comes in the form of triglycerides, and it’s these triglycerides that provide the cells with energy.
Most tissues in the body can use fatty acids for fuel, but the main ones that we are interested in are skeletal muscles and the liver. A few tissues, such as the brain, can’t use fatty acids directly, however they often can use ketones which are made from fatty acids.
Triglycerides are composed of three fatty acids held together by a molecule called glycerol. In order to store or use fats for energy, pancreatic enzymes are released into the stomach acid, then the resulting monoglycerides and free fatty acids are absorbed in the intestines.
After passing the intestinal wall, these compounds recombine into triglycerides which bond with other fats, proteins and cholesterol to form lipoproteins before entering the bloodstream.
When they reach their destination, they are either broken down and stored as free fatty acids in the liver, or as body fat, or they are fully metabolized and used as a source of energy by your muscle fibers.
When you eat excessive amounts of food, whichever form it is in — including carbohydrates, fats, and in some cases even proteins — your body will convert and store the excess food energy as body fat.
Especially too much sugar, fructose, or excessive fat intake can cause fatty liver, which has been linked to obesity and chronic inflammation that can advance to fibrosis, cirrhosis, and cancer.
Adipose tissue is more than just a storage depot for fat. It actually secretes hormones known as adipokines that help regulate energy balance and influence several body functions. When the body has excessive (or dramatically reduced) fat, the type and quantity of adipokine secretions change, with consequences for our health.
Researchers are currently exploring how adipokines influence obesity and chronic diseases such as type 2 diabetes, hypertension, and heart disease.
For example, obesity increases the release of the adipokine resistin that promotes inflammation and insulin resistance — factors that predict heart disease and diabetes. Similarly, obesity decreases the release of the adipokine adiponectin that protects against inflammation, diabetes, and heart disease.
Unfortunately, just mobilizing fatty acids out of the fat cell on its own will not lead to fat loss. It is important to get the fatty acids away from the fat cell and to other tissues, where they can actually be burned. So yes, you need to exercise or be generally active during the day in order to lose fat!
If the fatty acids are not moved out of the adipose tissue, the body will re-store them in a process called re-esterification. The effectiveness of the transport out of the fat cell to other tissues depends on the adipose tissue blood flow (ATBF). Other factors, such as hormones and even outside temperature, can also affect ATBF.
The body appears to close off blood flow when it is cold, and increase blood flow as the temperature increases.
Aerobic exercise has been shown to effectively increase ATBF, with the effect becoming greater as the duration increases.
The body is always using energy, so when dieting, performing long term aerobic exercise, or prolonged fasting, it must draw on its internal energy stores.
Its prime source of energy is glucose, so the body’s first step in maintaining energy is to break down carbohydrates, or glycogen, into simple glucose molecules in a process called glycogenolysis.
It then breaks down fats into glycerol and fatty acids in a process called lipolysis. And these fatty acids can then be broken down directly to get energy, or can be used to make glucose, through a multistep process called gluconeogenesis.
Diets that are high in monounsaturated fats can help with weight loss and may reduce risk factors for heart disease and other conditions too — when combined with regular exercise, or supported with an active lifestyle.
Healthy, monounsaturated fats are most commonly found in whole food sources such as olive oil, nuts, seeds, and some animal-based foods. Olive oil in particular has been shown to help reduce the risk of cancer, inflammation, and insulin resistance.
Fat has many other benefits too — as we have seen here it provides the body very effectively with energy, it can also insulate against temperature extremes, protect against shock, maintain cell membranes and cognitive function, and regulate hormone balances.
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Ayda Ersoy is a nutrition and fitness director at The Diet Doc Hawaii. She can be reached at DietDocHawaii.com, Ayda@DietDocHawaii.com or 276-6892
