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Stop eating for 36 hours once a week, and yes, you’ll drop a few pounds. You may also protect yourself against heart disease, cancer, diabetes, and stroke. To top it off, you’ll enjoy the food you do eat that much more. Maybe it’s time to start fasting.

By: Tollie Schmidt

Monday morning in Los Angeles. Skies are bright, air is clear, and as I walk my dogs down the street, I easily spy 10,000 calories. Commuters gobble PowerBars in traffic. The diner at the corner does brisk business. Two giant cheeseburgers hover over me on a billboard. But none for me, thanks.

I haven’t eaten since Saturday night. Thirty-six hours. I’m not hungry. A bit spaced out, maybe, but in a peaceful way. This is maybe my 5th weekly fast in a row. I do this honestly, because I love food. It’s my favorite comfort, my most exquisite treat. I’ve forgone clothes, electronics, and a better car in order to budget more for braised beef ravioli, fresh mozzarella, and Chateau Rouget.

But a few years ago, something began to turn. Knowing the way food soothed me, I started slipping – a shake from the diner, tangerine chicken from the local Chinese place. My eating became mechanical, joyless. This is an easy trap to fall into: From hunter-gatherer ancestors, we retain a genetically encoded anxiety however unconscious, that food can be scarce. So we’re hard-wired to eat when we can, even though food is ubiquitous. It’s also cheap and tasty.

For America, primal fear plus abundant food equals an obesity epidemic. For me, my love of food devolved into an imperative to eat that cared little for the distinction between fast food and foie gras. Apostasy. I committed to a year of weekly fasting to see if I could restore the relish to my life.

There are as it turns out, many reasons to fast. I was only vaguely aware of the health benefits when I started, but studies suggest that regularly abstaining from food lowers your heart rate and blood pressure, staves off diabetes, and protects your tissues from the ravages of free radicals.

“Fasting poses a good kind of stress, much like exercise,” says Mark Mattson, Ph.D., a National Institutes of Health neuroscientist. “Our cells respond by increasing their ability to cope with other, stronger stresses.” In rodent studies, fasting also confers dramatic resistance to cancer, brain aging, stroke, and heart disease. Since I began this experiment, I’ve lost 15 pounds (from 189 to 174) and shaved two points from my body-mass index. More important, I love food agin.

Fasting does, in fact, improve your taste-bud sensitivity to sweet and salty flavors, according to a 2004 study in BMC Neuroscience. And fasting forces me to make better choices when I do eat. On either side of a fasting day, I crave smaller, more vegetal meals. Come midweek, I want to celebrate. I go for dry-aged steak and stinky cheese with less guilt and more gusto. And more patience. In practice, an empty gut brings a sense of peace, as if I’m on vacation. This calm, along with the promise of health, has kept me fasting beyond the term I initially committed to.

In the last hour of fast this Monday morning, I feed my dogs, then my gf, then myself. Nothing tastes better than a sip of grapefruit juice poured into that calm. And strawberries. Yum. Three of them and I’m full.

Four Rules Of Fasting:

1. Don’t fast unless you’re in good shape and eat right already. People who are severly overwight or don’t eat a generally healthful diet could see blood-pressure drops, low nutrient levels, or other problems, says Joel Fuhrman, M.D.

2. Start off easy. A few 24-hour fasts will help your body and mind adjust. Two nights without food can be a long time for novices. But after several weeks, making the jump to 36 hours becomes a matter of skipping just one more dinner.

3. Bookend the fast with the right meals. If you eat a carbohydrate laden large meal before you fast, it will make you hungrier the next day. Similarly, a small meal with protein at the end of the fast will prevent you from feeling overstuffed.

4. Pace yourself. You want the hardest part – the end of the fast – to hit while you’re sleeping so your brain is sharp during the wakeing period of the fast. If starting with a 24-hour fast, go from breakfast to breakfast, not dinner to dinner.

Nearly a week later, I’m ready again. Eager for it, really: my gustatory reset button. I typically fast from Saturday night until breakfast on Monday, drinking only water, only when I’m thirsty, and beginning and ending the fast with light meals. Tonight it’s kale, rice, chicken, and melon – a high-fiber selection. Last meals can lead to constipation if they don’t contain enough fiber to push through your system. I read this in a book and its veracity by ignoring it.

The book, called Celebration of Discipline, by Richard Foster, is a guide to spiritual Christian practices. Tonight, I read the fasting chapter again. Foster’s tone works for me. There’s no histrionics – going without food is no big deal. This was critical for my first few fasts. When my inner food-child threw a tantrum, I responded with nonchalance, and it worked.

I didn’t look beyond Foster for a while, and I’m glad. Most fasting information out there is nonsense. Charlatans promote it as part of their weight-loss scams. Most doctors are equally as ignorant. When I asked one about it, he mumbled something about electrolytes and cardiac arrhythmia before surrendering: “They don’t teach fasting in medical school.”

They ought to, if only out of respect to the billions of people who fast for religious reasons, from Yom Kippur to various Christian and Hindu holidays to Ramadan. And there is strong, if scattered, scientific literature that includes empirical evidence from doctors with fasting experience; a smattering of more-controlled experiments in humans; overwhelming evidence from animal experiments; and a sort of amicus brief from a studied field called calorie restriction. In calorie restriction, participants eat only 60 percent to 70 percent of their weight maintenance intake. “This consistently decreases the biological rate of aging and increases life span,” says Eric Ravussin, Ph.D., a physiologist at the Pennington Biomedical Research Center.

One empiricist is Joel Fuhrman, M.D., author of Fasting and Eating for Health and a family doctor in Flemington, New Jersey, who has put thousands of patients on multi-day fasts and followed their vital signs and blood work closely. “For a healthy person, medical supervision is not needed for a 5-day fast,” he tells me. He’s never seen electrolyte depletion or potassium loss, which can cause cardiac arrhythmias, prior to the 10th day of a fast.

Dr. Fuhrman instructs patents with inflammatory problems like lupus and arthritis to consider episodic fasting. Rodent studies show this anti-inflammatory benefit, as does at least one human study. James B. Johnson, M.D., from the department of surgery at Louisiana State University, put nine overweight asthma patients on a near-fasting regimen every other day for 8 weeks. On average, those patients lost 8 percent of their weight, lowered their cholesterol by 20 points, and improved their airflow by 15 percent due to less airway inflammation. “There’s nothing out there that would work as well as that, other than systemic steroids,” says Dr. Johnson, author of The Alternate-Day Diet.

Other studies piece together what happens to hunger strikers and starvation victims. The bottom line: Our bodies are built to go long stretches without food. When you eat, your liver and muscles store up energy in the form of glycogen. When you fast, your body feeds off that glycogen for several days and then starts burning your fat stores. Once those are depleted, starvation starts: The body breaks down muscle first and then organs, which leads to death after 8 to 10 weeks. This timeline assumes access to water. Dehydration can kill in days.

Foster fasts to find God. For me, fasting is spiritual, and a time for reflection. I close me eyes and munch on my last bit of melon. I picture a hunter-gatherer ancestor. He hasn’t killed game in days, but that’s okay. He has bodily wisdom to last many weeks. That’s an awesome capability. My 36 hours is a mere gesture.

How Fasting Improves Your Health

Mitochondria inside your body’s cells use carbohydrates to make cell fuel. The molecular by-product: Free radicals that damage DNA, impair cellular function, and promote cancer. Here’s how fasting may help.

1. Fewer free radicals: During a fast, the mitochondria, sensing a lack of food, become more efficient. Lie a cleaner-burning fire, they  start producing fewer free radicals per calorie burned, says Eric Ravussin, Ph.D., a clinical investigator at Pennington Biomedical research Center.
2. More Antioxidants: The diminishing number of free radicals is met by an increase in antioxidant production within your cells. These enzymes “search and destroy free radicals,” says Mark Mattson, Ph.D., a neuroscientist at the National Institutes of Health.
3. Stronger cells: This cleaner calorie-burning also produces a surge in beneficial stress hormones, such as cortisol and growth-hormone. “Exercise during a fast and the increase is even greater,” says Ravussin, adding that the hormones prepare cells for worse stresses. “They’ll better resist tumors and rebound faster from a heart attack.”

Any other day I develop a headache if I skip coffee, but not on fasting days. I have no idea why. I often play racquetball with my friend Scott, and I exhibit fierce energy on the court. My body feels springy on fasting mornings, and my mind is as clear as water.

I occasionally choose different days to fast, to work it comfortably around dinner parties, travel, and whatnot, and by now I’ve done it on every day of the week. I’ve gone to work, driven long distances, taken hikes, had sex, and lifted weights while fasting. Admittedly, I’m flying in the face of alternative medicine, which considers fasting a detoxifying process best done by easing into it. Don’t send so much blood to your muscles, the theory goes – send it all to your liver. Without digestion of food to deal with, the liver can scrub the blood, ridding it of pesticides, food additives, and other toxins. These exit through your pores, sinuses, colon, and urine. Some people apparently suffer from acne, rashes, and headaches while fasting. I don’t. But my tongue coats over with a white film, and my breath stinks. These are classic signs of detoxification – according to my acupuncturist, anyway.

There’s nothing alternative about Mark Mattson, Ph.D., who’s conducted the most animal research on fasting. Holding appointments at the NIH’s National Institute on Aging and Johns Hopkins, Mattson has put thousands of rodents on intermittent fasting and on calorie-restriction regimens. He’s also done the most to aggregate the findings from other labs. In the 2005 Annual Review of Nutrition, Mattson summarized the benefits of fasting on every-thing from cholesterol to cancer.

The mental benefits of fasting excite Mattson most. Fasting increases production of several molecules, including brain-derived neurotrophic factor, which protects the neurons from all sorts of disease down the line, Mattson tells me. As a result, fasting rats show better memory, cognition, motor function, and neurogenesis (production of new nerve cells from stem cells). He’s shown that fasting mice bounce back from heart attacks and strokes better than everyday eaters do.

If just a fraction of the fasting benefits seen in rodents were conferred by a pill, drug companies would be racing to prove them in humans. The human studies so far have involved too few participants to yield sweeping claims. Having said that, in the studies that have been done, there are no documented down-sides to fasting. None. But that doesn’t mean they’re not there. One problem that crops up in the similar world of calorie restriction: Fertility takes a dive. I know my sperm is okay. All my swimmers are full stream ahead, I’ve been tested.

I admit it: On Sunday afternoon, I usually get hungry. The primal drive to eat is strong. I’ve cut a few fasts down to 24 hours. But I noticed during the week I got lazy. I started eating crap again, so I swore back to the 36 hours and now I’m hooked! When your whole body feels refreshed, energized, your mental focus is sharp and craving more knowledge and challenges. You know this is what optimal health and diet truly is about, this is what allows you to truly enjoy the journey life has allowed you to travel.