PORTSMOUTH, VA. (Catholic Online) - Dear Dr Denton: As the Lenten season unfolds, can you tell me the effects of fasting on my body?

Lent is my favorite spiritual time of the year. For me, it is a time of great joy. It cleanses my mind, body, and most importantly my soul. I have spent the past year building up toxins from the world I live in. Largely, it is the result of my own choices. I came off the holiday season and .presto, I was not quite as spry as I was in October when I was enjoying those little red rubies we call apples.

While Lent can be viewed as a season of sacrifice and doing without, I believe that it is the season of rebuilding and laying down a foundation that will help to direct our spiritual well being and perhaps our overall health.

What do I mean? 

Prayer and fasting leads us to a deeper closeness to God and to peace and beauty within.  Interestingly, fasting also gives our body a time to clean out the weight of a heavy year. Fasting on a purely physical level does have some significant and wonderful benefits.

Let´s just start with calorie reduction. In the US, the American food factory produces enough food to fill every citizen with 3800 calories per day. By the way, we only need approximately 2000 calories per day to sustain a normal sized person.

So, how does fasting play a role in our health and wellness?

The most profound way is in the calorie restriction. Studies performed on animals and humans where caloric intake had been restricted have shown that it leads to increased longevity (a longer life). Please understand that I am NOT speaking of extreme fasting. The radical extreme fasts that are proclaimed to be the "cure all" for the body are far from the truth.

The problem is that caloric restriction data is often used as a means of promoting extreme diets and starvation type "de-toxing."  "You should be able to smell the toxins coming off your body," is the common type of language used to promote an extreme diet or what is called a detoxifying fast.

The truth is that in the extreme detoxification diets and low calorie fad diets the body does give off an odor that is often reported to be the "toxins" coming off.  In reality, when you drive your body into a starvation mode the body goes into ketosis. That is what has the somewhat sickly sweet smell. Not toxins, just ketosis.

In fasting, the body has a decreased calorie intake. The body needs those 2000 or so calories to stay at an even weight and function. When the calories are less than our daily needs we start breaking down our energy reserves.. fat and muscle. In a short term fast such as a day of bread, honey, and water the body burns those fat stores.

In a diet where carbohydrates are limited for days to weeks, or absolute calorie reduction in the 1000 range, the body responds by burning both fat and muscles stores. In absolute starvation when the fat is gone, the body burns muscle.

That is why we see the horrible pictures of children with large bellies and thin limbs. The muscles of the abdominal wall - as well as the muscles on the limbs - have been used for calories. Muscle is made up of protein. When the muscle breaks down it forms ketones as a waste byproduct.  In the ideal world, we fast enough to burn the excess fat stores. We also control our tendency to indulge our disordered appetites through focused prayer, meditation, exercise, and simple discipline.

How does fasting help the mind and body?
 
In the short term it is best understood through understanding the value of rest. The body needs rest to heal itself and to grow. During a day of fasting, the stomach and bowels are rested. The toxins that are produced by the body in the breakdown of food and the toxins in the food we eat are thereby limited. Remember those free radicals from my earlier articles? They are decreased because there are fewer being made as waste in your body. In addition, fewer are brought in with the foods we eat.

How does fasting help the brain?

Simply stated, the caloric rest has a mind clearing effect. As Americans, we often eat high carbohydrate, high calorie meals. Initially, with food intake, the brain gets a high calorie boost but as we begin to digest large amounts of food our blood flow is directed to the gut to help with nutrient breakdown and transport. Later, the insulin release is often higher than the caloric intake so the brain has a moment where the sugar in the blood is too low and we get tired and feel cloudy.

By fasting, the calories and carbohydrates we eat are limited. The body does not surge with too much insulin. Instead a small amount of calories are brought into the body so we can function and the remainder of our needs come from our own fat ...