Over the years of human existence, nature provided seasons of plenty and seasons of lacking, creating periods of feasting and starvation. We’ve worked to eliminate these cycles, but as it turns out, the waxing and waning of the food supply might have been the healthiest thing for us.
The idea of fasting for health has been around since the time of Hippocrates. Religions have long maintained that fasting is good for the soul. In the 1930s, researcher Clive McCay from Cornell University discovered that rats who were subjected to stringent calorie restrictions from an early age lived longer.
Periods of fasting are reported to increase mental alertness, improve mood, and strengthen commitment to ideals. Other benefits include:
- Decreases cardiovascular risk (alters blood cholesterol levels)
- Lowers diabetes risk
- Decreases cancer risk
- Protects against some effects of Alzheimer’s and Parkinson’s disease
- Weight loss
Ways to incorporate fasting into your life can range from abstaining from solid food periodically for a few days to a week on a regular basis. Fasting accelerates the clearing-out of waste left by dead and damaged cells. The failure to keep up with accumulated debris is believed to be one of the causes of chronic disease associated with aging. I find it convenient to fast on days in which I am traveling or flying or when there are limited choices for healthy food.
The idea of fasting counters the current trend to consume five or six small meals a day (there is very little evidence to support the benefit of this). Extra meals often end up as sugary or manufactured snacks, usually not vegetables or home cooked snacks. Moreover, this practice supports our 24-hour eating culture. In The 8-Hour Diet, David Zinczenko and Peter Moore stress that we must have periods in the day in which we don’t consume food. This not only helps weight loss but also gives the “cleansing wave” of the intestinal tract an opportunity to do its job. They recommend restricting eating to a limited time frame, i.e. an 8-hour window. Creating a time zone for eating helps establish good food rules, such as no eating in car, while walking on street, or while watching TV.
Michael Mosley, author of The Fast Diet: Lose Weight, Stay Healthy, and Live Longer with the Simple Secret of Fasting, suggests the path to optimal health is to eat normally for five days a week and fast for two which consists of 500 – 600 calories, plus non caloric fluids (water, tea). He reports that “the body goes into repair and recovery mode when it no longer has the work of storing the food being consumed.” It is important to note that Mosley does not recommend feasting on the other five days but instead eating a healthful and sensible diet.
Please note that for those with certain conditions, such as Type 1 diabetes or anyone with an eating disorder, fasting is not advised. If you are already extremely lean, do not fast. Children should never fast. Pregnant women should eat according to government guidelines without limiting their daily calorie intake. Before embarking on a fast, discuss it with your health care provider, especially if you are on any medications.
Many of us have an innate fear of being without food and this, mixed with abundant and always available food, has wreaked havoc on our global health. My own experience is that it is often freeing to take a break from thinking about food, or centering our schedule around food. It teaches us that it is okay to be hungry.