Naturopathic doctors often use diet as a foundation of their treatments and therefor strive to deliver useful information to support the health of their patients. Early animal research revealed caloric restriction as a possible "fountain of youth", but a more recent study did not support this hypothesis. Still there is surprising evidence to support its use for specific health reasons. While some caloric restriction enthusists are extreme and far fetched, periodic fasting has been practiced in various religious and cultural settings for thousands of years. We will discuss some of the evidence and application of this old but new diet approach to promote health. 

What are the positive effects of calorie restriction on the body?

When we deprive our body of calories, the body gets the energy it needs for daily activities and processes from stored sources such as fat, stored glucose, and muscle at different time intervals. For an average person it would take about 48 hrs of complete fasting before the body starts breaking down muscle for fuel, before this it uses fat and stored glucose. When we reduce calories, the process causes changes to our physiology that are thought to prolong life. The exact processes that are effected and how they may prolong life is not clearly understood but it is an area of intense research.

With cancer for instance, intermitent calorie restriction had been shown to sensitize cancer cells to chemotherapeutic agents they were previously insensitive to. According to Dr. Longo at UCLA, a pioneer in caloric restriction for cancer, this occurs or two main reasons. The first is that cancer cells need a constant supply of glucose to survive and we are removing that supply. The second has to do with the cancer's mutations. Under normal circumstances our bodies have plenty of glucose. When a normal cell turns into cancer, the genes mutate to better adapt to this normal environment. These mutations then set the cancer cells up to dived more favorably under high or normal glucose environments. When the glucose is taken away through calorie restriction, the unnerving is much less favorable for these cells and the cancer has more trouble dividing. Add chemotherapy to this and cancer cell growth will really be blunted and or lead to cell death. Normal cells don't have any trouble at all living under these circumstances, however. They can use keytones and fatty acids as fuel without any trouble. Dr Longo is getting positive results using periodic fasting in his patients with chemotherapy resistant cancers.

Another key area where calorie restriction is thought to have a positive effect is the neuroendocrine system. As we age many of our hormones like, growth hormone, testosterone, progesterone, estradiol, DHEA, insulin, cortisol, and thyroid decline and  /or become imbalanced. Caloric restriction seems to have balancing effect on the neuroendocrine system as a whole. In particular it has shown to reduce fasting insulin and improve insulin sensitivity, the key dysfunction in type two diabetes. While there is likely something to this theory, more evidence supports the use of caloric restriction for reducing reactive oxygen species. 

Reactive oxygen species come about every time our bodies make energy. As we age the process of making energy becomes less efficient and more reactive oxygen species result. The problem with reactive oxygen species is that they cause damage to all the nearby cells they come in contact with creating inflammation. As a matter of reference, the usefulness of antioxidants are from reducing the damage that reactive oxygen species make. With caloric restriction there are less reactive oxygen species and less cellular damage and inflammation. 

The application of calorie restriction or therapeutic fasting.

As you can imagine research on the effect of calorie restriction in humans is difficult and to date there are no longterm randomized trials in humans. There is a large body of research in other animal species showing a benefit. A recent study on Recess monkey showed no life extension on those eating calorie restricted diets verse unrestricted diets. This study refuted earlier research showing a benefit in the same species. The jury is still out on whether caloric restriction extends life but it seems logical enough that it would help looking at body weight only. 

The typical caloric restriction approach (in animals and humans) is to reduce your daily caloric intake to below what the unrestricted intake is without causing malnourishment. This can be achieved by adapting a diet high in nutrients and low in calories similar to a Paleolithic or Okinowa type diet. Reducing total calories by about 10%- 25% of your normal would give rise to the benefits noted in the animal studies. This is also the structure of a typical diet that would be used for generalized weight loss too. The animal studies suggest you would have to do this for approximately 20 -30 years to gain 5 years of added life. While 5 years of added life is of debatable value, what seems more important is the quality of life you have. In the animal studies the psychological benefits seen were quite remarkable showing older animals performing task and exercises that are typically only seen in their younger counterparts. So while quality of life may be reduced by eating less, the ability to function and act in the world with vigor and vibrance may be significantly enhanced. 

In general we feel that maintaining a healthy body weight while eating nutrient dense foods is more important and health promoting than reducing calories. While the two are related they are slightly different. 

Naturopathic doctors use of calorie restriction as part of nature cure.

Nature Cure refers to the use of natural modalities and treatments that stimulate the bodies innate healing responses as a way to enhance or stimulate recovery. Contrast hydrotherapy, acupuncture, herbal treatments, counter irritants, and therapeutic fasting, are all examples of nature cure used by naturopathic doctors. When it comes to calorie restriction, therapeutic fasting either with juice or water only fasting, have been in practice for centuries. The thought is that by fasting you give the body energy to focus on health promotion rather than digestion and distribution of food and nutrients. The inherent desire to do this is seen when we get sick with a cold or flu, for instance. Typical therapeutic fasting can last from 24hrs to 7 days. It should be noted that anything beyond 48hrs should be monitored by a physician for things like blood sugar, blood pressure, etc. Many that do such fasting report feeling more alert and energetic within 24hrs. Still this type of therapy is certainly not recommended for everyone.  

Those with mental health disorders, and those prone to eating disorders should not follow such a regimen. It is debatable for those with diabetes to partake in this. While improved insulin sensitivity would be advantageous, it is likely not be sustained once normal eating is resumed unless weight loss is maintained. Those that are taking diabetes medications would be advised to steer clear. For the general population without diabetes, or mental health issues, periodic therapeutic fasting could offer benefit if nothing more than a period to detoxify and revitalize the body. In these case there are specific protocols to follow that are tailored to the length and purpose of the fast. 

To learn more about nature cure techniques, therapeutic fasting or other health topics, click on the link below for a free consultation with one of our naturopathic doctors Arizona.