Eat, Fast, Feast: Heal Your Body While Feeding Your Soul—A Christian Guide to Intermittent Fasting

by Jay W. Richards

To see these regenerative benefits, Longo advises a fast of three and a half days—three days and four nights. He recommends people do this once a month until their test results get where they should be.

As before, drink lots of water every day and keep up your intake of electrolytes (sodium, magnesium, potassium).

Elijah fasted for forty days and forty nights during his long journey to Mt. Horeb (another name for Mt. Sinai).

In every case, the forty days/nights/years were a trial that came just before something new.

Don’t know where to start? Commit the Prayer to St. Michael to memory and pray it throughout your fast.

A prayer to an angel in a "Christian" book on fasting

Consider the Scottish man Angus Barbieri, who in the mid-1960s fasted for 382 days. He subsisted on water, tea, coffee, vitamins, potassium, and sodium supplements until the very end of the fast.

By the time he reached his twenty-seventh birthday, he had reached a corpulent 456 pounds with no end in sight.

After more than a year without food, he reached his goal of 180 pounds. Even years later, he had inched up only to 196 pounds.

In fact, some famous “overfeeding” experiments at the University of Vermont showed that healthy adults find it hard to overeat over the long haul. Force-feeding subjects caused weight gain at first. But then their weight leveled off. Why? Well, when you stuff your stomach with food, various hormones like leptin signal satiety, making it really tough to keep shoving food down your gullet. Some of the Vermont subjects disliked it so much that they dropped out on the study. The extra calories also led subjects to burn more calories. “Total energy expenditure in the subjects increased by 50 percent,” notes Jason Fung.2 The rule seems to be, Eat more, burn more.

There are only a few other people known to have lived over 300 days without food. He’s an outlier, not a model.

If you’re really overweight, though, you know it already, even if you don’t know the medical definition.

The key virtue of the BMI? It’s easy to calculate. You just measure your weight and height and do a little arithmetic. But it has some vices as well. For one thing, it doesn’t measure body fat, which is what matters.

Take Arnold Schwarzenegger. At his peak, when he won several Mr. Olympia contests, he was 6'2" and weighed 235 pounds during competitions. So his BMI was 30.2, which ranked him as obese, even though he had less than 5 percent body fat! (For comparison, the average competitive marathon runner has around 10 percent body fat.)

Fortunately, there’s a third method for determining if you have too much of the (wrong kind) of body fat. It’s free and easy. You just divide your waist circumference by your height in inches. Your waist should be no more than half your height. If your score is below 0.5, in other words, you’re in pretty good shape.

With type 1 diabetes, the body attacks the beta cells in the pancreas that produce insulin. This causes them to fail, leaving the person with little or no insulin. People with this disease wither away because their bodies can’t use the food energy they consume. The sugar they need for fuel gets filtered by the kidneys and passes out of the body during urination.

This can go on for years, with the pancreas pumping ever more insulin into the blood to clear it of rising blood sugar levels. What can’t be cleared returns to the liver, which converts the sugar to fat.

When you start fasting and eating a ketogenic diet, your blood sugar will drop. Injecting insulin, in particular, could then bring it down into the danger zone.

So, what’s the problem with our modern diet? It’s not merely macronutrients. Different traditional diets vary radically in this way. Some are higher in fat, some higher in protein, some higher in carbohydrates.

Yet despite this variety, none of these diets includes large amounts of sugar, highly processed carbs, or industrial seed oils.

As far back as ancient Greece, fasting was used to reduce the number of seizures in children.

In the 1920s, German scientist (and future Nobel Laureate) Otto Warburg was studying cancer cells and made a startling discovery. He noticed that they draw almost all their energy anaerobically (without oxygen), by fermenting glucose (called glycolysis). One clue tipped him off: the cells produced lots of lactic acid, which is a by-product of glycolysis.

Warburg, knowing all this, noticed something weird about cancer cells: they fermented glucose for energy, even though oxygen was present. (This feature of cancer cells is called, confusingly, aerobic glycolysis, or simply the Warburg Effect.10) From this discovery he inferred that cancer must develop inside the cell’s power plants, later found to be mitochondria. Cancer, then, would be a disease of mitochondrial dysfunction.

Cancer cells, unlike the healthy cells in your body, must derive most of their energy from glucose (as well as a protein called glutamine). They don’t have a choice. Cancer cells, in most cases at least, can’t turn ketones into energy.

Fasting in particular might be a double punch, since it would reduce the sugar and protein available to feed the cancer. That is, fasting may preferentially starve cancer cells and preserve healthy cells.

A leading scientific proponent of this protocol is Thomas Seyfried of Boston College. He has laid out the details in his 2013 book Cancer as a Metabolic Disease.

Under the pressures of fasting, our cells start to repair themselves. In mitochondria, this is called mitophagy, and in the cell, autophagy (literally: self-eating).20 Rather than holding on to worn-out organelles, proteins, and membranes, cells in eukaryotes (everything from yeast to humans) can recycle their parts and use them to meet their energy needs. A lack of nutrients from food is a key trigger for this process. There are several ways this is signaled in the body. A spike in AMPK, mentioned above, is one. A drop in another protein kinase called mTOR is a second. (mTOR is a sensitive nutrient sensor.21 The presence of just a few grams of the amino acid leucine can shut off autophagy.) A third trigger is low levels of insulin and high levels of its hormonal alter ego, glucagon. What do these signals have in common? They’re all stimulated by fasting.

But what if a cell is beyond repair? There’s an app for that too! It’s called apoptosis—programmed cell death. (That sounds scary, but don’t worry: you lose tens of billions of cells through apoptosis every day.)

Cancer cells, in contrast, ignore the Grim Reaper when he comes calling. They want to live forever. This is just one of several weird features that make cancer deadly. Cancer cells also stay stuck in the growth state and resist signals to stop.

In her great book The Upside of Stress, Stanford psychologist Kelly McGonigal reveals the surprising research that shows that your state of mind has a lot to do with how stress affects you.25 If you believe a stressful event is bad for you, it probably will be. If, in contrast, you see it as a test to help you improve, it may do just that.

In fact, if you’re in good health, you should be able to do a forty-eight- or seventy-two-hour fast without much trouble.

How long should you go? As long as the only thing you experience is hunger, and you don’t start feeling nauseated or sick,

Whenever you break your fast, be sure to do it slowly. Your insulin and blood sugar will be low. Your ketones will be high. Your stomach may have shrunk, and your body will be producing less digestive acid. In fact, much of your G/I tract may be taking a nap. Start with some soup or bone broth, then some vegetables, then meat and all the rest. In fact, you can simply follow the order of a multi-course meal: soup, salad, entrée with vegetables, dessert. Just spread out the first two dishes to give your system time to warm up.

The basic rule (assuming no one is elderly or in poor health) is, the older the family member, the more stringent the fast.

In fact, Daniel’s practice isn’t really a model for a general fast—despite the popularity of the “Daniel Fast” in Christian circles. First of all, it’s really abstinence rather than fasting. Eating a veggie diet for a few weeks might be a good idea,3 and it might be part of a longer seasonal fast such as Lent. But going vegan for a stretch isn’t, strictly speaking, a fast. Still, for a non-fasting church, it could be a step in the right direction.

“God is committed to rewarding those acts of the human heart that signify human helplessness and hope in God,” notes John Piper.

The world passes over in silence the two periods that precede Christmas and Easter—Advent and Lent.

When Christmas greetings turn up in the middle of Advent, Catholics and other Christians who follow the liturgical calendar complain that everyone’s doing it wrong. They’re technically right: Christmas hasn’t yet come! Still, this is a losing battle, at least for the wider secular world. That’s because Lent and Advent are both traditional seasons of fasting. There’s no clear financial incentive for Amazon, Walmart, and Starbucks to push fasting, abstinence, and penance for two and a half months every year.

many people think that if juice doesn’t have “added sugar,” then it’s low sugar. In truth, juice is mainly sugar removed from its natural matrix of soluble fiber.

There’s no simple answer, beyond the truism that longer fasts are harder, and riskier, than shorter ones.

Don’t make longer fasts harder, and less helpful, than they should be. For instance, if you try a water-only fast for a week or longer, you should not be underweight when you start, and you should talk to your doctor first. No matter what you choose, avoid fruit juice fasts.

Sure, everyone concedes that organisms look designed. As arch-atheist Richard Dawkins famously put it in his book The Blind Watchmaker, “Biology is the study of complicated things that give the appearance of having been designed for a purpose.”

Darwin’s conjecture has become the main prop for modern materialism. This view holds that matter and energy are the ultimate reality. Things like consciousness, purpose, and religious beliefs are just so much froth on the mindless churning of molecules.

In the face of these findings, the materialist is reduced to positing countless unobserved universes just to explain away the origin and fine-tuning of this one. Or to claiming, as the late Stephen Hawking did, that “the universe can and will create itself from nothing.”3 Let that sink in. It is truly materialism’s reduction to the absurd.

But what about biology? Do we have good reason to believe in the sweeping power of Darwin’s mechanism? Could it really have generated all the life forms we see around us? No. The evidence points in the opposite direction: Beyond the borders of an organism’s diverse population, selection-and-mutation soon hit a brick wall. If an adaptive change needs more than two coordinated mutations to succeed, it won’t happen, however generous you are with the time window.4 Any major innovation would require far, far more mutations. It’s not clear that even directed mutations could turn one organism into another. Thousands of years of dog breeding, for instance, have never given rise to a new species.

Of course, natural selection explains some things. Our best example of its power is antibiotic resistance in bacteria.

Despite huge populations and superfast reproductive times, however, they never become anything more than humble bacteria. Moreover, such mutations exact a fitness cost. The resistant strain of bacteria has an advantage against an antibiotic, but not because it has evolved a superpower. Rather, it has lost something that just happens to give it an advantage in that odd environment. When the antibiotic-resistant bacteria must compete with the ordinary strain of bacteria absent the antibiotic drug, the ordinary strain wins.

The problem is not just “that random mutation and natural selection are grossly inadequate to build complex structures,” argues biochemist Michael Behe, “they strongly tend to break them.” As a result, and a bit paradoxically, Darwin’s process can “help form new species and new genera, but chiefly by promoting the loss of genetic abilities. Over time, dwindling degradatory options fence in an evolutionary lineage, halting organismal change before it crosses the family line.”6

Darwin’s mechanism can preserve the fittest members of a population. It can tweak around the edges. As others have said, it can explain the survival of the fittest but not the arrival of the fittest. It’s a filter, not a creator.

Darwinism, in contrast, is a Procrustean bed. It requires us to assume that our entire metabolic systems—which can switch between different sources of energy, adjust to different kinds and amounts of food, balance our need to find food with the need to store and conserve energy, and so forth—was an adaptation to food scarcity. Remember, Darwin’s mechanism has no foresight. It’s blind. It can’t think, Humans will someday spread out across the globe into many different ecosystems, with wildly varying types of food supplies. Let’s evolve a complex system to thrive on wildly different diets—from the whale blubber and organ meat diet of the Inuit to the carby tubers of the Kitavans. No, the mechanism had to cobble together all that flexibility, all that capacity, from our earliest ancestors one tiny glitch at a time, as adaptations to the environment, with no planning ahead for future exigencies. That’s because the mechanism can only select for current survival advantage. It can’t build a working, interdependent system ahead of time. Foresight, however, can. And there’s the rub. Foresight is the exclusive domain of intelligent agents. Man’s capacity to rapidly adapt to different diets has about it, in other words, the look of a plan.

Innovation frequently comes with costs that we can’t reckon until later. Think of cars, smartphones, and social media. And when we discover such costs, we should do what we can to mitigate them.