This week I am going to wrap up my short series on nutrition and the three areas that tend to undermine any good nutrition program. Most of us know eating habits, discipline in eating right and meeting our nutritional needs are the three areas I am talking about.

I have covered eating raw whole foods, eating like our ancient ancestors and getting your proper amount of macronutrients. Now I want to cover an area that may not seem like it fits the nutritional puzzle, which is fasting.

Fasting has been a part of human nutrition all the way back to the Paleolithic era. The human body has evolved around the fact our food sources were either feast or famine. One of the reasons our modern diet, high in empty calories and saturated fats, works against us so much is our body's ability to take excess calories and store them as fat reserves. This is the body's way of preparing for the next famine. We tend to forget we are the sum total of our evolution and we have evolved to survive based on key nutrition factors. Storing calories is one of those great yet problematic factors designed for our survival.

Now how does fasting become good for you? Our body uses fasting to reset a number of internal systems so to speak. Short fasts of 24 hours or less actually improve insulin sensitivity and this is a pretty big deal. When your cells are sensitive to the up and downs of insulin, they do a much better job regulating your blood sugar levels after meals. When you lose insulin sensitivity you can start to develop risk factors for metabolic disease and diabetes.

As I started to research fasting and its benefits and/or negative effects, I was surprised to find most of the information and studies showed a clear upside to fasting. Now before we go too far, it is important to note that fasting may not be for everyone. There may be preexisting medical reasons you should not fast, so consult with your doctor before you jump into any form of fasting.

Let's start with a few of the key benefits that studies have shown come from intermittent fasting.

1. First the obvious, fasting forces your body to use stored energy in the form of fat oxidation, which leads to weight loss.

2. Studies have shown fasting increases the secretion of growth hormone. Growth hormone increases fat burning among other things.

3. As mentioned above, fasting improves insulin sensitivity. Insulin resistance is a widespread problem and it is now well established that insulin resistance can lead to type 2 diabetes.

4. Studies also show that fasting may promote longevity and also benefit neurological health. There have been a number of supportive studies, which support this aspect very well.

5. Short fasting for 16 to 18 hours has been shown to reset your inner clock and help improve sleep problems. Breaking the fast when you wake will reset you to this new waking pattern.

Short-term fasting is referred to as intermitted fasting and has been a part of many individual fitness regimens for some time. When you add fasting to a solid whole foods nutrition program, then include an active lifestyle, you will see the most benefit from fasting.

In a 1986 study it was found that fasting before exercise increased fat usage as fuel and lowered the rate your muscles used up its glycogen stores. Not everyone likes to be active or work out on an empty stomach but for short bursts of activity studies show improved performance and fat burning.

Fasting has an effect on insulin, which is a hormone that promotes your cells to gather glucose from your blood and store in the form of glycogen in your muscles and liver. When your body has good insulin sensitivity, it becomes much more efficient when handling the use of glycogen and fat stores for energy. Again, this is one of the more important aspects fasting does as it relates to your nutrition.

Some additional benefits of being active after or during a fast is it gives you improved recovery, better muscle toning after exercise, and better glycogen retention since your body adapts to increased activity while you have low glycogen stores in your system.

Having an active lifestyle and starting a regular program of fasting is not something everyone will agree with. There are a few groups like cyclists that have used fasting as part of their training to drop weight prior to racing in an effort to increase power and endurance. There are other fitness groups that believe fasting creates muscle fatigue, loss of mental focus and reduced endurance. This aspect of nutrition will always be hotly debated. I think it is fair to say that results from fasting will be different from person to person. And of course not everyone should fast due to medical issues.

Fasting as an overall part of your nutrition is natural. We have not evolved eating abundant foods year-round. When you add intermittent fasting to a nutrition regimen of eating natural raw whole foods, along with a proper balance of macronutrients you start to have a good start at pulling your nutrition health together.

Staying hydrated is a key aspect to keep in mind with exercise and fasting.

Keep in mind, if you're someone who has a poor nutritional diet, fasting is going to be difficult. The other thing to be concerned about is if you do give fasting a try, the general rule of thumb is it's better to be active or exercise after you break your fast, but some people mix fasting and exercise together with some good results. Again, this becomes a personal preference based on how your body reacts to fasting.

Finally, if you try fasting, it is very important to check with your doctor first and stay very hydrated during your attempt.

Judd Jones is a director for the Hagadone Corporation.