Wednesday, May 9, 2012

Here is a little study I did on energy, ketosis and how your body burns fat.


The purpose of this research document is to better understand how our body uses energy and what can be done to burn more stored fat. How do we burn body fat? This seems to be the main question people want answers too. There are many factors, many covered below, some not. This article covers how and why fatty acids (fat) are burned and used as energy. There may be some medical conditions that could make some of this information not applicable, but for most of us it is.

The Research.

Below I have researched the major components which are part of the process of burning body fat. Using the research for each component I produced various conclusions at the end of the research.

Fatty Acids:

Are stored as fat in fat cells around your body, around your belly, on top of muscles, and in-between organs. Generates ATP (energy).

The energy yield from a gram of fatty acids is approximately 9 Kcal (37 kJ), compared to 4 Kcal/g (17 kJ/g) for carbohydrates.

ATP - Energy for use in your body (including metabolism). The main energy source for the majority of cellular functions including muscle movement and breathing.

ATP comes from Carbohydrates and Fatty acids. Carbohydrates first need to be broken down into glucose and fructose (sugar). Fatty acids first need to come from the citric acid cycle (which uses Ketone bodies). Both the breaking down of Carbohydrates and fatty acids ( citric acid cycle ) are used to produce ATP.

Ketone bodies (ketones) - The by-product of turning fatty acids into energy (ATP). Your liver and kidneys do the job of turning fatty acids into energy. Ketone bodies are used as energy for your brain and heart. Can be reconverted for use in the citric acid cycle to produce fatty acids for ATP.

Ketones are produced when your body is low on carbohydrates.

The brain gets a portion of its energy from ketone bodies when glucose is less available. Up to 75% of the energy your brain need can come from ketones depending on how much glucose is available.

Unused ketone bodies will break down after around 5 hours and leave the body as waste.


When you’re body produces more ketone bodies than it can use it is in the state of ketosis.

Glucose - A form of carbohydrate. Energy in the blood that travels around your body to give it energy. ATP can use this directly. If you have lots of Glucose in your system, your body will use that glucose to produce ATP before any other sources, including fatty acids.

Glycogen - Stored in your muscles and liver. Used for muscles and other tissues. Glycogen is broken down and converted again to glucose when needed.

Protein - Only used as fuel when carbohydrates and fatty acids are low or unavailable.


“Food Energy”, is a by-product of converting nutrients such as fat, carbohydrates, protein, fiber, acids and other nutrients into energy. ATP amounts can be used as a way to measure food energy. Some energies are stored (mainly as fat) easier than others, such as fat and carbohydrates.


1. ATP (energy) can come from both carbohydrates and fatty acids. When your body lacks carbohydrates, ATP will come from fatty acids, which in turn creates ketones, which in turn can be reconverted to help generate more fatty acids (which come from fat stores) (as well as be used as energy for the brain and heart).

2. Being in a state of ketosis could indicate your body is using fatty acids for energy. After all, Ketones are a by-product of the breaking down of fatty acids...however, not being in ketosis does not mean you are not using fatty acids (see ketosis above for the reason).

3. Being in a state of ketosis seems to be almost like cheating. Why bother cycling for 2 hours to deplete your body of carbohydrates so that your fatty acid production can kick in?

4. This could explain why people with less body fat need to eat more carbs for events such as triathlons and marathons. If you don’t have any fat, you don’t have any fatty acids to produce energy! I plan to steer clear of my low carb diet once my weight is gone.

5. It seems that calorie restriction alone can not guarantee as much as a low carb diet can. Eating 1000 calories worth of snickers candy won’t allow your body to use fatty acids as energy where eating 1000 calories of steak, salid and eggs, will.

6. If you want to burn fat, why would you want to use carbohydrates as energy. Carbs do not come from your fat storage cells. Fatty acids do!

Research Sources: UC Berkeley, College of William & Marry Student Review, Wikipedia, misc medical books and medical journals.

1 comment:

  1. Very Useful study .... very informative ....
    I have also put up a blog about some Best Fat Burning Foods ........ Check it out and let me know your comment .....


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