Jay W. Richards - Eat, Fast, Feast: Heal Your Body While Feeding Your Soul—A Christian Guide to Fasting

The Physician Within

W eve spent decades debating what we ought to eat. Should we eat bread? Should we eat butter? Should we eat a low-fat diet? Should we eat a high-fat diet? The combinations are endless and the advice ever-changing. Despite this often-misguided fixation on what to eat, we spend little time studying another, just as crucial question: when to eat. Based on a paucity of scientific debate, many of us have been advised by experts to eat early and often. The idea that there are times when we should abstain from eating has been a minority view, to say the least. This is especially strange since fasting is one of the oldest health remedies in history. It has been part of the practice of virtually every culture on earth. Every major religionChristianity, Judaism, Islam, Buddhism, and Hinduismincorporates fasting into its practices. And yet rigorous fasting has virtually disappeared from modern life.

To be clear, fasting is not starvation. Fasting is the voluntary abstinence from food for spiritual, health, or other reasons. One may fast for any period of time, from a few hours to a few months. As a healing tradition, fasting has a long history. Hippocrates of Kos (c. 460c. 370 BC), widely considered the father of modern medicine, wrote, To eat when you are sick is to feed your illness. The ancient Greek writer and historian Plutarch (c. AD 46c. AD 120) echoed these sentiments, advising, Instead of using medicine, better fast today. Plato and Aristotle were also staunch supporters of fasting. Yet few who study their works today in search of wisdom follow these Greek philosophers advice on fasting.

The ancient Greeks believed that medical treatment could be discovered by observing nature. Humans, like most animals, dont eat when they become sick. Just think of the last time you were sick with the flu. Probably the last thing you wanted to do was eat. Fasting seems to be a universal human response to all manner of illness. Its ingrained in our human heritage, as old as humankind itself. Fasting is, in that sense, instinct.

The ancient Greeks also believed that fasting improved mental clarity. Again, our common experience bears this out. Think about the last time you ate a huge Thanksgiving meal. Did you feel more energetic and mentally alert afterward? Or instead, did you feel sleepy and a little dopey? Probably the latter. That huge influx of food rerouted blood to your digestive system, leaving less blood for brain function. Fasting does the opposite, leaving more blood for your brain.

Other intellectual giants were also great champions of fasting. Take Paracelsus (14931541), the founder of toxicology and one of three fathers of modern Western medicine (along with Hippocrates and Galen). Fasting is the greatest remedy, he wrote; the physician within. Benjamin Franklin (17061790), one of Americas founding fathers and renowned for wide knowledge, once wrote, The best of all medicines is resting and fasting.

Fasting for spiritual purposes is widely practiced in many parts of the world. It remains part of virtually every major religion. Jesus Christ, Buddha, and the prophet Muhammad all shared a common belief in the power of fasting. The practice of fasting developed independently among different religions and cultures, not as something that was harmful, but something that was deeply helpful to the human body and spirit.

Many Buddhists consume food only in the morning, and then fast daily from noon until the next morning. Buddhists may also undergo the rigors of various water-only fasts for days or weeks on end. Many Eastern Orthodox Christians follow various fasts over 180 to 200 days of the year. Dr. Ancel Keys, the famous nutritional researcher, often considered Crete the poster child for the healthy Mediterranean diet. One key factor may have been that Cretans followed the Greek Orthodox tradition of fasting.

Muslims fast from sunrise to sunset during the month of Ramadan. The prophet Muhammad also encouraged fasting every week on Mondays and Thursdays. Ramadan differs from most fasting protocols since fluids as well as foods are forbidden. Further, since eating is permitted before sunrise and after sunset, recent studies indicate that daily caloric intake actually rises a lot during this period. Gorging before sunrise and after sunset, especially on highly refined carbohydrates, negates much of fastings benefit.

Many people assume these are just outdated folk and religious traditions that have no basis in science. But the truth is just the opposite. There is now a mountain of scientific and clinical evidence that fasting is good for us, and that it may be the cure for the so-called diseases of civilization that afflict so many modern people.

Most North Americans subsist on sugar (glucose) for energy. Our bodies can run on glucose and fat but they tend to use glucose whenever its available. When the supply of sugar is cut off, the body, once it uses up its stored sugar (glycogen), switches to burning fateither from the diet or from the body. Unfortunately, constant infusions of sugar in our diet keep our insulin levels high. Insulin is an important hormone that, in the presence of blood sugar, signals to the body to burn sugar and store any extra as body fat. And, to judge from the latest health statistics, were storing more and more fat, and harming our health in the process.

Fasting strikes at the root of this problem. Done right, fasting lowers our insulin levels and helps reset our metabolism, without any harm to our health. Different lengths of fasts have different effects, but the basic idea is to deplete your bodys stored sugars until it starts burning fat. Some parts of your body, such as the brain, still need some glucose but mostly use an alternate fuel, ketones, which are made from body fat. Strictly speaking, there are no essential carbohydrates.

But wont fasting slow down your metabolism and deplete your muscles? No, it wont. In the early days of a fast, your body actually increases its energy expenditures and protects lean mass through various hormonal signals.

But wont you be crazy hungry and get hungrier and hungrier the longer you fast? No. Fasters are often less hungry after several days without food than they were at the beginning, no doubt because their bodies are efficiently using body fat for all their energy needs.

The effects of fasting, in other words, are just the opposite of the persistent calorie reduction of long-term diets, which rarely work in the long run. What makes fasting different from dieting is its intermittent nature. Diets fail because of their constancy. The defining characteristic of life on Earth is homeostasis, wherein competing processes balance out in a state of equilibrium. In the body, any constant stimulus will eventually be met with an adaptation. With persistent calorie reduction, the body at some point responds by reducing total energy expenditure. This leads to the dreaded plateau in weight loss and eventually to weight gain. Several recent studies have confirmed this.

We have spent decades obsessing over the question of what to eat, but we have virtually ignored the crucial aspect of meal timing. Weight gain is not a uniform process. Average yearly weight gain in North Americans is about 1.3 pounds per year (0.6 kilograms), but that increase is not constant. The year-end holiday period produces a whopping 60 percent of this yearly weight gain in just six weeks. Most people then lose some weight after the holidays, but not enough to counter the gain. The long-term effect, of course, is that we get fatter and fatter.

We should not always be eating, and we should not always be fasting. Feasting must be followed by fasting. When we remove the fasting and keep the feasting, we eventually get fat and sick.