Using Energy from Fat
Does Fat Convert to Glucose in the Body?
Carbohydrates in the form of glucose, are your body’s preferred energy source.
When we don’t consume enough carbs or use them all up, your body will start to use fat and some protein for energy.
Fat is a rich energy source and can fuel body in a fasting state.
Fat can be converted to glucose, but the process is so inefficient that you loose energy, hence why our body looks to burn carbs primarily.
Using macronutrients in the body
When you eat food you are giving your body energy.
When you digest food you are breaking the food down into smaller parts: Carbs turn into glucose. Protein becomes amino acids. fat breaks down to triglycerides and fatty acids. All these smaller parts of food: Carbs, Protein and Fat can be used for energy.
ATP: Adenosine Triphosphate
Plants, animals and humans alike all depend on ATP to power cells. Your body simply wouldn't function without ATP.
You need resources from food to make ATP (energy for us to run on). Carbs are the easiest source of fuel for the body, it is a faster and more simple process than getting it from fat or protein.
Your digestive system breaks down carbohydrates into glucose, which is the simplest of all sugars. Your body breaks the glucose down further using different chemical reactions. The process of breaking down glucose is called glycolysis.
Lactic Acid Cycle
When you do an intense workout like sprinting, your body uses lactic acid to make energy. This is called anaerobic exercise because you don’t need oxygen to make energy.
There are two major draw backs of anaerobic energy: lactic acid builds up slowing and stopping chemical processes that make energy and two, you cannot make ATP from this process because the body is not using oxygen.
Aerobic Energy
At rest or during an endurance workout, your body uses aerobic energy. That means it's using oxygen to create fuel.
It's much more efficient than anaerobic metabolism. You end up gaining 30 ATP molecules per molecule of glucose.
Using Energy from Fat
We can extract energy from fat when we run out of carbs.
To extract energy from fat, your body breaks down fat cells or fat from the food you eat into triglycerides. This process is called lipolysis. Triglycerides are the type of fat that goes into your bloodstream, which makes it available for the rest of your body to use.
Fat metabolism yields about twice the amount of energy per weight as glucose, which makes it a rich source of energy.
Once fat has broken down during digestion, some of it gets used right away for energy, and the rest is stored. When we runout of carbs to burn the body will use fat for energy.
Dietary fats consist of: saturated fat, trans fat, monounsaturated fatty acids and polyunsaturated fatty acids including omega-3.
Fat is digested by chewing your food which breaks it down into smaller pieces and travels down to the stomach. The stomach lining produces acids and enzymes that break down food further so that foods can to the small intestine. Your liver produces bile that helps you digest fats and certain vitamins. Certain enzymes help break down macronutrients such as lipase and amylase. Lipase aids in fat digestion, while amylase helps break down carbohydrates, bromelain, and papain.
After the fat has been digested, fatty acids are passed through the lymph system and then throughout the body via your bloodstream to be used or stored for energy, cell repair, and growth.
Here are some examples of foods that contain healthy fats:
vegetable oils, such as olive oil, sesame oil, and canola oil
nuts, including almonds, pecans, and cashews
fatty fish, such as salmon, sardines, herring, and trout
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