Is Fasting Unhealthy?
Fasting has been practiced for centuries. But can it really help you lose weight and get healthier?
It sounds so simple - no choices, no counting calories, no cooking. Just say 'no' to food, and start fasting for quick weight loss and other health benefits.
After all, Beyonce did it. She said she lost 20 pounds by fasting (and using a concoction of syrup, lemon juice, water and cayenne pepper) for her role in Dreamgirls.
But what about the rest of us mortals? We wonder:
And finally, is fasting healthy? Although fasting has been practiced for thousands of years, the question is still a subject of intense medical debate. WebMD consulted experts onweight loss and fasting for some answers.
Fasting and Weight Loss
If you weed through all the controversy, you'll find that most medical experts agree on one thing: fasting is not a healthy weight loss tool.
"The appeal is that [fasting] is quick, but it is quick fluid loss, not substantial weight loss," says Madelyn Fernstrom, PhD, CNS, founder and director of the University of Pittsburgh Medical Center's Weight Loss Management Center.
Fasting and Weight Loss continued...
Even worse for dieters is that fasting for weight loss "distracts people from the real message of how to lose weight: lower fat intake, eat five fruits and vegetables a day, drink water and stop drinking other liquids, walk 30 minutes a day, and get more sleep," says Fernstrom, an associate professor of psychiatry, epidemiology, and surgery at the University of Pittsburgh School of Medicine.
In addition, other practices that are often combined with fasting for weight loss, such ascolon cleansing, carry their own risks.
"Fasts are sometimes accompanied with enemas to cleanse your intestinal tract, and that can be very dangerous," says Fernstrom. "The intestinal tract has a lot of good bacteria. When you are changing that balance, the good bacteria are affected, too."
Does Fasting Detoxify the Body?
Here's where the debate gets intense.
"There is no scientific evidence it will detox the body. The issue of fasting to cleanse the body has no biological basis because the body is real good at that by itself," says Fernstrom. "The liver is a natural detox center; the lungs, the colon, the kidneys, [the lymph glands] and the skin get rid of toxins."
But Fuhrman, who has supervised hundreds of patients' fasts for medicinal purposes, disagrees.
"We know that the body is unable to rid itself of toxins when we eat a diet low innutrients," and that applies to most Americans, even those who think they are healthy, he says.
"Americans eat 51% of their diet from processed foods and foods low in phytochemicals and antioxidants," he says. "So you see a buildup of waste products in the cells -- AGE, advanced glycation end products -- that build up in cellular tissues and lead toatherosclerosis, aging, diabetes, nerve damage, and the deterioration of organs. This is basic science and physiology every doctor learns in medical school."
Along with improving your overall diet, fasting is one solution to that buildup of AGE, according to advocates like Fuhrman.
"Fasting allows the body to most effectively remove these waste products," he says. "The body is designed to fast; we do it every night."
How does fasting remove toxins from the body? When you go without eating for more than a day or two, the body enters into ketosis. Ketosis occurs when the body runs out of carbohydrates to burn for energy, so it burns fat.
"And the fat is where the body stores many of the toxins it absorbs from the environment," Fuhrman says.
Spiritual and Religious Fasting
Whether fasting can help rid the body of waste buildup is a matter of controversy. But fasting has been used for religious and spiritual purification for centuries.
Nearly every religious text you can name, from the Old and New Testaments of the Bible to the Quran and the Upanishads, calls upon followers to fast periodically as a rite of spiritual purification, penitence, or preparation for union with God.
Medical Reasons for Fasting
Another topic on which there is medical agreement is the benefit - actually, the necessity -- of fasting before surgery.
"You don't want the body to be digesting food as it manages the slower breathing [and other body changes] under anesthesia," says Fernstrom.
Fasting is also required to get accurate readings for certain medical tests. Short-term fasting before tests for cholesterol and blood sugar levels, for example, helps achieve a more accurate baseline count.
Fasting to Treat Disease
Fasting advocates also claim that the practice can effectively treat serious health conditions, from arthritis and colitis to heart disease and depression.
In his practice, Fuhrman tells WebMD, he has seen fasting -- combined with improving the diet before and afterward -- eliminate lupus, arthritis and chronic skin conditions likepsoriasis and eczema. He says he has also seen fasting heal the digestive tracts of those with ulcerative colitis and Crohn's disease, and lower blood pressure.
"Fasting followed by a vegetarian diet interferes with the immune system's activities, especially if the immune system is overreacting, as it does with ," and other auto-immune diseases, he says. He cites half a dozen studies published in medical journals ranging from the American Journal of Physiology - Endocrinology and Metabolism to the Scandinavian Journal of Rheumatology.
Studies published in The Proceedings of the National Academy of Sciences and The Journal of Nutrition in 2003 showed that mice forced to fast every other day, while eating twice the normal amount of food on non-fasting days, had better insulin control, neuronal resistance to injury, and other health indicators than mice fed calorie-restricted diets.
Fasting may yield psychological benefits as well.
"I use very brief fasting with my patients to help them cope with stress and depression," says Agnese Barolo, a life coach in contemplative practices in New Rochelle, N.Y. "I start them with just a few hours â so they learn to say no to food. Itâs the first step in taking control of their lives."
Fasting to Treat Disease continued...
Many are so encouraged that they try longer fasts, she says.
"I know some doctors say there is no scientific evidence for the curative powers of fasting," Barolo says. "But there is a reason every culture in every country has practiced some form of fasting for thousands of years."Â
Fasting is not advisable for everyone. But for those whose medical conditions do not respond to other treatments, Fuhrman says, "sometimes fasting four to five days a month can help them break to a next level of immune competency."
He adds that "it will only work if you frame the fast with good nutrition before and after. For most medical conditions, if you stick to a strict diet, you donât even need fasting."
Fuhrman cautions that certain people should not fast, including:
- Pregnant women.
- People with wasting diseases or malnutrition.
- Those with a history of cardiac arrhythmias.
- People with hepatic or renal insufficiency.
And anyone who fasts for extended periods should do so only under close medical supervision.
Fasting for Longer Life
"There are hundreds of studies showing that when animals are fed fewer calories they live longer," says Fuhrman.
Studies on animals ranging from earthworms to monkeys have shown that alternating cycles of fasting and very calorie-restricted diets is a reliable way to extend the lifespan.
"The excess calories Americans eat shorten their lives," says Fuhrman.
If you want to live longer, Fuhrman's best advice is to "eat healthy and fast periodically."
The time may come," Fuhrman says, "when not offering this substantially more effective nutritional approach will be considered malpractice."
Is fasting unhealthy?
in Islamic way; with no water
There are many types of fasting. It depends which style of fasting you choose. Some types of fasting are hazardous to your health while others are beneficial towards your wellbeing
As the Ramadan fast lasts from dawn till dusk, the body's energy can be replaced in the pre-dawn and dusk meals.
This provides a gentle transition from using glucose as the main source of energy, to using fat, and prevents the breakdown of muscle for protein.
Dr Mahroof says the use of fat for energy helps weight loss. It preserves the muscles and eventually reduces your cholesterol level. In addition, weight loss results in better control of diabetes and reduces blood pressure.
“A detoxification process also occurs, because any toxins stored in the body’s fat are dissolved and removed from the body,” says Dr Mahroof.
After a few days of the fast, higher levels of endorphins appear in the blood, making you more alert and giving an overall feeling of general mental wellbeing.
A balanced food and fluid intake is important between fasts(even in Islam, we are strongly encouraged to eat food, fruit and veggies and plenty of water before the sun rises). The kidneys are very efficient at maintaining the body’s water and salts, such as sodium and potassium.
So, i believe that fasting is healthy to the extent of what method of fasting you are following. There are many types of modus operandi in fasting and you have to figure out what type you want to use.”
“No fasting is not unhealthy, infact it is healthy practice. I am a dietitian and I have read whole physiology. By keeping fast body detoxifies which removes free radicals from the body thus keep body free from diseases.”
“No!! In fact it has some benefits which people don't know like Fasting rests digestive system, however production of digestive acids continue to secret but at reduced rates. Fasting also promotes detoxification, Fat is burnt during fasting And the toxins are released.Other than this fasting reduces blood sugar, this rests the pancreas . Some studies show that fasting promotes resolution of inflammatory diseases and allergies.Fasting corrects high blood pressure. This keeps the metabolic steady and within limits.Fasting promotes rapid weight loss. It reduces the store of fats in the body.Fasting Promotes Healthy diet.It has been observed that fasting reduces craving for processed foods. It promotes desire for natural foods, especially water and fruits.When an individual is on balanced diet in between fasts, this can boost immunity. Fasting May Help to Overcome Addictions.Fasting is a good practice, if properly implemented. I know that there are some negative effects too but they are because of ill mannered fasting.And I don't consider them very serious.Effects of fasting on a healthy person are limited. Negative effects are inconveniences, especially in the early days of Ramadan, such as headaches, nausea, sleeplessness, etc.”
“Yes it is. Not drinking water for hours is the unhealthiest part as you will get dehydrated. This is even a bigger problem when Ramadan takes place in the summer when the weather is hot. Due to dehydration and the lack of food for a long period of time, you might easily get distracted and lack energy. Also, the healthiest eating schedule is having small meals throughout the day rather than having 2-3 big meals. Fasting also means not eating for hours and then having a meal. Which is the opposite of the healthy way and something that will tire your digestive system.
Also, quite a few people avoid their health problems. If your blood pressure is on the low side for example, not eating or drinking anything for hours will make your blood pressure drop down even more. If you have digestive problems or genetic weakness towards digestive diseases, keeping your stomach empty for hours can also trigger the problem.
Unless you have a health problem none of these would cause big problems if you fasted for 2-3 days, in fact it might even have some health benefits (except for not drinking water.) It gets damaging when it lasts for longer than that.”
Why Fasting is Bad for You
Lots of buzzwords pop up when fasting is mentioned. "Cleansing", "Toxins", "Spiritual", "Holistic"…its a long list that recently inducted Anna Hazare in it's litany.
Science, however doesn't advise a diet that leaves you looking like Mahatma Gandhi (even if you're feeling like Mahatma Gandhi). This is why.
There's a man in America named James Randi. He'll pay a million dollars to anyone who can successfully prove, under controlled conditions, any alternative remedy that actually works.
India's abundance of mixing myth and fact, however is first tested by the Indian Rationalist Association, known for debunking such phenomenon and exposing lies behind Indian superstitions. They busted the sleight-of-hand tricks of Sri Sai Baba, successfully explained the mechanics behind milk-drinking statues and the sweet sea water of Mahim Creek, Mumbai.
IRA's founder and President President Sanal Edumarku even took on a tantrik's threat of death by Indian black magic on national TV, sitting calmly throughout the India TV episode called The Great Tantra Challenge that drew millions.
The few pseudo-scientific practitioners of breatharianism (a school of fasting) have all died - yes, died - after controlled observation and investigation by the IRA.
48 hours after fasting, your body is going to give in, and start feeding the hunger with it's own deposited fats. This may sound healthy, but that level of fat burning produces ketone , which are harmful. Ketosis (the production of ketones) cause severe acidity (not the kind that Eno will soothe) - and begin damaging body organs.
"During the break-up of stored fats ketones are generated. High level of ketones in the blood can damage the liver, kidney and heart muscles."
Even God can't help people with diabetes who go on a fast - their bodies can go into hypoglycemia - which is fatal.
This is the truth behind long term fasting - the truth that's seeping into Anna Hazare's cells as I write this.
Fasting leads to slower metabolism and higher cortisol - which is a recipe for high stress.
Fasting Damages Your Muscles
Your body will feed off your body; cortisol will leach amino acids from your own muscles so that it has sugar to consume. This sugar will go to your brain, kidneys and RBCs . While fat is useful to the brain, it likes sugar, and red blood cells.
Fasting Damages your Digestion
"Fasting creates an abnormal physiological state. Those who adopt fasting as a means of detoxification ultimately end up developing gastrointestinal problems," says Dr S K Thakur, senior consultant, gastroenterologist, Moolchand Medcity.
Your body has peak times for secretion of digestive enzymes (at breakfast, lunch and dinner) are "In the absence of food, these enzymes keep circulating within and damage the lining of the digestive tract. This leads to acid reflux, gastritis problems and even ulcer," says Dr Thakur.
The gall bladder's bile contents are used for digestion when you eat. When bile doesn't have food to act upon, it gets stored inside your gall bladder.
"In the absence of food, this bile keeps accumulating inside the gall bladder. Gradually it can turn into sludge, leading to the formation of stones," cautions Dr Thakur.
Fasting Kills Your Immunity
When you don't eat, your intestinal tract (responsible for over 70% of your antibodies) will stops working for your immunity. In the absence of antibodies, bacteria, toxins, and viruses suddenly have a easier time staying alive inside your gut. When the raw material necessary for a intestinal tract (sufficient calories, proteins, and certain vitamins and minerals) is missing, your immunity is shot.
Which is why people die from long term fasting.
Fasting Won't Help Weight Loss
What you're losing is actually water weight (the water content in food also counts!). And theweight lost due to ketosis comes back - you'll crave high fat foods after a fast. You might even think you deserve some off-time from your diet and forget about exercising and eating right. Eating normally will bring back your hunger, but the slower metabolism, combined with an increased appetite will make you fat.
Long term ketosis kills - your body is converting protein into sugar, and this protein comes from the liver, spleen and muscles. Soon, your blood glucose level falls, leading to electrolytes imbalance occurs - and then death.
Fasting Gives our Bodies a Rest
Every second, hormones are at play, enzymes are swimming about, and your energy cells are storing energy. All this needs food. No food will put a strain on your body's vital processes - not 'rest' it.
The Fasting Detox Myth
The most vocalized, yet the least scientifically understood myth, a vague and faulty understanding of the body purging toxins when we fast is used to justify fasting. This belief doesn't take into account the processed nature of our food, and the stringent food safety regulations.
In fact. fasting puts stain on our liver and kidneys which are continuously working to "detox". If you are healthy, your body is pretty much toxin free already. And the above-mentioned ketones, along with increased nitrogen products will put more strain on your body. The only cleanse you can have is eating healthy food and a regular bowel movements.
As for what keeps Anna Hazare going, has anyone wondered why he only drinks water from steel tumblers instead of clear glass?
The Facts on Fasting for Your Health
Fans of periodic fasting say the practice can help with everything from allergies to weight loss. Are they right? Here, the good, the bad, and the hungry on fasting to feel better.
April 22, 2011 — Ritual fasting has been part of religious traditions for thousands of years, from Muslims who fast during daylight hours in the month of Ramadan to Mormons who take a regular break from food the first Sunday of each month. But a recent growing body of research shows that abstaining from food intermittently may have physical as well as spiritual benefits — the latest, a study from Utah researchers that found that occasional fasts (defined as extended periods of time in which people generally abstain from all food and drink except for water) may reduce the risk of heart disease and diabetes.
Google “fasting for health” and you’ll get more than 7 million hits, ranging from doctors who recommend it in their practices to treat a range of diseases, spas that promise detoxifying food-free vacations, and message board postings from devotees who say that fasting makes them feel clearer mentally and more fit. “I fast whenever my body feels like it needs a reboot,” says Yoli Ouiya, 31, a New York City blogger who writes about eco-friendly living. She fasts once every few months.
But is fasting a good idea for your health? Possibly, says David Katz, MD, MPH, director of the Prevention Research Center at Yale University. Every day, organs such as the liver, kidney, and spleen work to remove and neutralize toxins from the body to keep our cells healthy. “When you fast, you eliminate input of additional toxins from food,” says Dr. Katz, “and there is a potential biological benefit to that.”
Leading researchers and experts share the details you need to know before you forgo food:
Your Body on a Fast
Thanks to our history as hunter-gatherers, human bodies are equipped to handle periods of not eating, says Benjamin D. Horne, PhD, MD, author of the Utah study and director of cardiovascular and genetic epidemiology at Intermountain Medical Center in Salt Lake City. And since the ancestors who made it through those lean times are the ones who survived, Horne suggests that our DNA may actually be coded to receive a benefit from fasting.
Here’s how your body reacts when you stop feeding it:
- When you eat, your digestive system breaks down carbohydrates into the sugar glucose, the body’s major source of energy. Glucose is absorbed from the digestive tract into the blood, which then travels to your body’s cells to provide them with fuel.
- If you haven’t eaten recently, the supply of glucose in your blood drops and your body turns to stored glucose, called glycogen, for energy.
- Once the glycogen is used up, your body begins to burn fat and muscle stores to make its own glucose to fuel your cells.
- After a few days without eating (which experts don’t recommend) your body kicks into ketosis mode, meaning you burn fat as the primary source of fuel, in order to spare muscle. You will lose weight in the form of body fat. However, ketosis also makes your blood will also become more acidic, and can cause bad breath, fatigue, and other unpleasant symptoms; long-term, it can lead to kidney and liver damage.
What Fasting Can and Can't Do for Your Health
1. Fasting may help your heart.
Fasting for a day once a month may prevent heart disease and insulin resistance, the precursor to diabetes, according to two studies from Utah’s Intermountain Medical Center presented recently at the American College of Cardiology’s scientific sessions. When researchers looked at the habits of 200 men and women, they found that those who fasted once a month were 58 percent less likely to have heart disease than those who didn’t (after they controlled for factors such as age, smoking status, and high blood pressure). They then set out to understand why.
In a smaller study, the scientists measured various blood levels in 30 healthy adults after one day when they fasted and one day when they ate normally. After they fasted, participants had huge increases in human growth hormone (HGH) — 13-fold in women and 20-fold in men, among other changes. HGH protects lean muscle mass and encourages the body to burn fat stores instead. “During fasting, your fat cells are being metabolized and used as fuel,” says Horne. “If fat is being used for fuel, in the long run you have fewer fat cells in your body.” This may mean less insulin resistance and a lower risk of heart disease later in life.
2. There’s a chance fasting can cut cancer risk.
Periods of fasting did slow the rate of cell division (a measure of cancer risk) in mice, according to an American Journal of Physiology study. The researchers aren’t sure why, but say it may result from a decrease in growth factors that results from nutrient deprivation. But since the science is preliminary, you shouldn’t fast solely for cancer-prevention purposes until there is more definitive research on humans, says study author Marc Hellerstein, PhD, MD, professor of human nutrition at University of California, Berkeley
3. The jury's still out on fasting for other ailments.
While there isn't much research on many of the diseases proponents claim fasting helps treat - multiple sclerosis, rheumatoid arthritis, and allergies among them — doctors say that if you’re medically able to fast safely (which rules out those with more serious health issues), there's no research against doing it either.
In fact, one small Iranian study of 40 adults with multiple sclerosis found that there were no negative effects from fasting during the month of Ramadan compared with a group who didn’t fast. "If you’re not on prescription medicine, generally in good health, and want to fast periodically because you feel you get a health benefit from it, we don't have evidence that this would be harmful," says Katz.
4. Fasting won’t help you lose — and keep off — weight.
“Fasting for weight loss is just another form of yo-yo dieting,” says Joel Fuhrman, MD, board certified family physician specializing in nutritional lifestyle medicine and author of Fasting and Eating for Health. While you may see a small drop in the scale, don’t expect the weight loss to last.
“The pounds that come off on a short-term fast are mainly water and storedcarbohydrates, which will come back as soon as you start eating again,” says Cynthia Sass, MPH, RD, author of the bestselling book Cinch! Conquer Cravings, Drop Pounds, and Lose Inches.
And if you’re tempted to fast one day as a green light to eat whatever you want the next, think again. “Weight loss is about energy balance — if you have consume fewer calories than you burn, you will lose weight,” Katz. “On the days you fast you have a calorie deficit. But what really comes into play is what you do on the other days.” In other words, you can negate the potential health effects of a fast by binging afterward.
Bottom line: True weight-loss success involves healthy eating (along with exercise habits) that you are committed to and can maintain over time.
1. Fasting can’t take the place of a healthy diet.
While there may be health perks to intermittent fasting, the research is still preliminary. Horne’s lab is currently working on studies that will evaluate how often and for how long people need to fast to see health benefits. One thing we know for sure about health: Eating well every day plays a major role in preventing heart disease, diabetes, and certain types of cancer. “Focusing on consistently eating enough nutrient-rich whole foods like fruits, vegetables, and whole grains snowballs into proven powerful benefits over time,” says Sass.
Another important thing to keep in mind: Just as fasting gives your body a break from toxins, it also saps your body of vital nutrients like vitamin D, calcium, and omega-3 fatty acids. “With fasting, you risk throwing out the baby with the bathwater,” says Katz. “As you create nutrient deficits on fast days, it may be difficult to compensate on the days you do eat.”
So if you choose to fast, you have to pack your diet with nutritious foods. “Fasting is not a way of fixing an otherwise broken diet,” says Katz. “It should be used only as a way of helping you establish a healthy way of eating, rebooting your body to focus on what’s important.”
2. Talk to your doctor before you start a fasting regimen
While fasting may have the potential to play a role in wellness, it’s definitely not for everyone. Specifically, if you have a history of eating disorders, diabetes, low blood pressure, anemia, are pregnant or nursing, or are on prescription medication, as well as other conditions/circumstances, fasting is not safe for you.
“If someone wants to use fasting as part of a medical intervention, they should discuss it with their doctor first,” says Horne. While there’s no evidence that fasting one to two nonconsecutive days per week is harmful for a healthy person, it could be dangerous for others, says Katz. See your doctor for recommendations that suit your needs.
When you talk to your doctor, make sure he’s aware of every drug you take, including over-the-counter meds and dietary supplements. A seemingly benign medication like acetaminophen can be harmful on an empty stomach.
Even if your doctor gives the go-ahead, don’t jump head first into fasting — it’s crucial that you understand how to do so safely, and in the context of a healthy lifestyle.
For instance, treat a fast day as a time of physical and emotional rest, not simply a day of not eating, says Fuhrman. You may feel fatigued and grumpy and face a higher risk of fainting, making fasting ideal for weekends and holidays as opposed to hectic workdays.
Talking to your doctor and educating yourself on fasting before you attempt it can mean the difference between a potentially health-boosting habit and a trip to the emergency room.
5 Reasons Intermittent Fasting Could Become a Bad Idea
A recent breakthrough study done at the University of Southern California (USC) found fasting for just three days could reboot your entire immune system.
Add that to the numerous potential benefits of intermittent fasting (IF), a wildly popular alternating eat-and-fast plan that varies wildly according to practitioner.
“Basically, it’s a technique that incorporates a weekly fast into your routine,” says Yuri Elkaim. “This method is great because it allows you to reap the benefits of fasting without leaving you feeling weak or deprived.”
A simple online search will yield numerous bloggers emphatically singing intermittent fasting’s praises for fat loss, increased stamina and vigor, improved focus at the gym and at work, breaking plateaus and, with this latest study, immune health.
Many studies do indeed show benefits. One in the Nutrition Journal concluded IF combined with calorie restriction and liquid meals helped obese women lose more fat and improve their cardiovascular disease risk.
Yet not all studies have concluded so convincingly. One in The American Journal of Clinical Nutrition found for women, alternate-day fasting could actually lower glucose tolerance and potentially crash your metabolism.
Women in another study published in that same journal experienced some benefitswhen they ate just one meal a day, yet they also had significantly increased hunger, blood pressure, and total, LDL-, and HDL-cholesterol concentrations.
Those and other problems coupled with some of my own clients gaining weight doing alternate-day fasting led me to conclude that, far from being a panacea, IF could potentially create these five detrimental consequences.
You can create or exacerbate eating disorders.
People rarely discuss this, but at its most extreme, intermittent fasting’s binge-and-purge mentality could trigger or exacerbate bulimia and other eating disorders. The “anything goes” mentality some experts permit during the feeding state could lead someone to overeat, creating guilt, shame, and other problems that only become worse over time. For someone with emotional or psychological eating disorders, IF could become a convenient crutch to amplify these issues.
You might chronically elevate cortisol levels.
“Skipping meals ramps up your stress hormone cortisol, which I consider a dark lord of metabolism,” Sara Gottfried, M.D., author of The Hormone Cure, told me. “From an evolutionary perspective, that short-term elevation was a win because it got the body to release fat as energy. Women seem particularly vulnerable to the dangers of intermittent fasting, which can keep cortisol elevated when it should be tapering down and create the an undesired effect of storing fat and breaking down muscle. Have you been around intermittent fasters? Not fun to be around!”
You can create an unhealthy obsession with food.
You’ve been fasting all morning, your coworker opens her broccoli chicken Chinese takeout at lunch, and suddenly all you can think about is what you’ll eat to break your fast at dinner.
Hunger proves a powerful evolutionary mechanism that kept us alive back in the day. With our modern ubiquitous bodegas and snack machines, hunger isn’t normally a problem and we rarely confront it. The problem is, when you’re starving everything else takes a backseat to eating.
With IF, that could become an obsession with mentally planning your next meal. Everything becomes about food.
You might over-rely on coffee.
Most IF plans allow caffeine, a stimulant that can keep you going for hours when you’re not eating. When you’re fasting, you might find yourself gravitating to coffee shops more often to get your fix that keeps you going without food. Especially for slow metabolizers, that third cup of dark roast could cut into your sleep cycle. “It is a vicious cycle, as caffeine can disrupt sleep and promote anxiety and depression,” writes Mark Hyman, M.D.
Coffee also amps up your stress hormone cortisol. “Cortisol’s main job is to raise glucose levels,” writes Gottfried in The Hormone Cure. “Even small increases in cortisol, such as those experienced when drinking caffeine, can raise blood sugar and increase insulin resistance.”
You could increase food intolerances and inflammation.
Fasting leaves you famished, creating a free-for-all dive into deep-dish pizza and a hot-fudge sundae when you actually eat. Never mind that a major caloric overload and blood sugar spike and crash that ultimately lead to more cravings. Your “break the fast” meal will likely contain gluten, dairy, and other potential reactive foods — perhaps in massive amounts — that contribute to leaky gut, paving the way for food intolerances, Candida and other gut issues, and increased inflammation.