The Pros and Cons of Fasting

I s Fasting Really Good For Your Health?

“Food deprivation is known to stimulate self-healing processes and rid the body of toxins.” Although there is a lack of scientific research to support this statement, many people swear by fasting and have incorporated it into their lifestyles. 

Let’s go over the pros and cons of fasting today. 

The most common fasting method is a period of time when there is no intake of food for at least 16 hours.

It would stimulate self-healing processes, allow easy weight loss, and rid the body of toxins... 

But what do we know about the effects of fasting on the body?  Does it really provide benefits? Does this practice involve any risks?

Fasting: A Metabolic Upheaval

Let’s talk about a 16 hour fast. In the case where there is no caloric intake and only water is allowed, it is called a complete fast.  If the individual does not eat and drink water, it is a dry fast.  Fasting can also be partial: the diet is then based on fruit or vegetable juices, which limits calorie intake to around 300 kilocalories per day (for an adult, the recommended intake is around 2,000 kilocalories). A fast can be continuous or intermittent (one or two days a week).

Deprivation of food for several days leads to an upheaval in the metabolism.  The body must do everything in its power to compensate for this loss of energy intake by alternately using its various fuel reserves. On the first day of fasting, nothing changes. The body uses glucose circulating in the blood or that stored in the liver. But by the second day, these stocks are exhausted. The body and brain then draw on fat and protein stores to make glucose. After five days, the body stops pumping its protein stores. And for good reason: when half of these reserves have been consumed, the individual is no longer viable. Energy must then be produced from fat stores - more specifically fatty acids - which can be directly used or transformed into ketones, substitutes for glucose.

From the 1960s, fasting began to be presented as a weight loss method.  Several studies have actually shown that fasting is, as expected, a way to lose weight.  However, the rapid weight loss in the first five days (about 1 to 2 kilograms per day) is primarily linked to a loss of water and sodium as well as the loss of muscle mass, not fat.  Weight loss is generally proportional to an individual's initial weight, and it decreases as the fast continues.  It can be maintained if the individual's eating habits and level of physical activity allow it.

Fasting has also been the subject of research on its impact on joint diseases, certain cardiovascular pathologies, or on the reduction of the undesirable effects of anticancer chemotherapy.  However, to date, there are no sufficiently numerous and rigorous scientific studies to conclude as to its therapeutic or preventive effectiveness," as the Ministry of Health reminds us.  In December 2017, a study even concluded that food deprivation can worsen the health of people with cancer.  As for the "detoxifying" properties of fasting, they are illusory: the idea that "toxins" clog our body is based on a false belief.

So What’s The Verdict?

The lack of proof of the effectiveness of fasting is not proof of its ineffectiveness.  Everyone is free to do what they want.  If it lasts less than seven days, is performed by a healthy adult, and at best is supervised, there does not appear to be much risk.  However, it can cause severe headaches, dizziness, or even discomfort, with uncertain results.  On the other hand, if it exceeds two weeks, severe mineral and vitamin deficiencies await the faster, but also liver problems and bone degradation.  But the most serious risk is the occurrence of cardiac arrhythmias which can be life-threatening.

The consequences can be particularly serious for certain populations: pregnant or breastfeeding women, because of the problems that the deprivation of food could cause to the baby;  children and adolescents, for whom there is a risk of slowed growth and puberty;  the elderly (risk of cardiac arrhythmia).  Some diseases are not compatible with fasting, such as anorexia, decompensated hyperthyroidism, epilepsy, multiple sclerosis, cerebrovascular failure, and advanced liver or kidney failure.  Likewise, be careful when taking certain medications (NSAIDs, corticosteroids, antihypertensives, antidiabetics, psychotropic drugs, antiepileptics, anticoagulants) together because of the risk of side effects. 

So considering the pros and cons of fasting, make sure you know the risks before you decide to give it a try!

• This post is tagged in:

• health
• diet
• weight loss
• Fasting