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Intermittent Fasting

Does the idea of fasting sound like another fad that will be shown to be no better than so many fads that preceded it? 

Interestingly, one type of fasting called intermittent fasting has been practiced since at least the beginning of recorded history.  With credentials like that, intermittent fasting can hardly be called a fad.

More likely, the fad we follow and don’t notice is the Standard American Diet (SAD) that took hold in the 60s and 70s.  For many, the SAD has become one long meal, supplemented by snacks, that lasts from waking up till going to sleep.

Prior to the modern era, it was rare for food to be continuously available. As far back as the Paleolithic period, gaps in the food supply happened frequently.  In response to these gaps, our bodies developed clever methods for dealing with food shortfalls.  Unfortunately, one of the best survival adaptations, storing fat for lean times, works against us in a world of abundantly plentiful hyper-palatable foods.

Depending on the severity of food shortfalls, people in different regions of the world developed different fat storing capabilities.  As a result of these differences in adaptation, where a person stores excess fat became a genetic characteristic. Many first develop excess belly fat (apple-shaped).  Many others developed excess hip/thigh area fat (pear-shaped.) While being pear-shaped confers a slight advantage in terms of not developing some chronic diseases (heart disease, diabetes), the best that can be said for being pear-shaped and overweight is that it’s “less bad” than being apple-shaped and overweight.

In the modern era, an abundance of food, especially hyper-palatable foods, has been implicated as a significant cause of unnatural weight gain and most chronic illnesses. Notably, these hyper-palatable foods are all created by adding Salt, Oil (fat), or Sugar (SOS) in ratios that hit what scientists call the ‘bliss point.’

While avoiding hyper-palatable food is the most important first step, a return to fasting, and intermittent fasting, in particular, has gained notice as a natural way of counteracting weight gain and many chronic diseases.  Contrary to what most would expect, the most significant advantage fasting confers for weight loss is not the result of creating a calorie deficit. Rather, for weight loss, the most significant effect is a reset of the “bliss point” at which food becomes appealing.  By lowering the “bliss point” carrots that might have languished in the refrigerator become quite appealing in the absence of hyper-palatable foods.

Hyper-palatable foods, Ebola, HIV, and COVID-19 all have a common characteristic.  All are challenges that our evolution did not prepare us to defend against.  Excess food only appears different because it kills us slower than the diseases that make headline news.

Throughout the day, our body is mostly in one of two states. Either we are in a state of absorbing nutrients from a recent meal or in a state of drawing upon these reserves for energy to support our activities.  At transition, we are partially in both states at the same time.  As we draw upon the nutrients that have been stored, we first use reserves that can be easily converted to glucose.  When the glucose reserves have been expended, the body calls upon stored fats for energy. Interestingly, when stored fat is called upon, the conversion to a form the body can use demands additional energy for the conversion. This energy of conversion increases the fat burned by about 25% beyond what is needed for walking, breathing, or other bodily functions.  Unfortunately, the body interprets this loss of fat as a danger signal that less fat will be available for the next food shortfall.  In response, the body down regulates to conserve energy.  For weight watchers, this is the dreaded plateau where no amount of effort seems to reduce weight.  Fortunately, fasting can be an important part of avoiding this dilemma.

The most popular form of intermittent fasting is one in which a person limits the time they feed themselves to an 8-hour window of time each day. Then for the remaining 16-hours, no food is taken. Usually, those 16-hours include eight hours of sleep. The advantage is that only eight waking hours of not eating is required to complete the 16-hour fast. Many other variations of intermittent fasting exist. For people that find the 8/16 schedule challenging, an easier way to begin may be a 12/12 schedule that involves widening the window of time food is eaten to 12 hours and fasting for 12 hours.  Another common intermittent fasting schedule involves skipping eating one or two days a week and then eating regular meals the remaining days. Longer fasts are possible but rarely done because most people find them overly challenging. Fast longer than two days are best done under medical supervision unless you are in excellent health or have sufficient experience to understand the potential problems.

The availability of food in almost every venue of life has made snacking hard to avoid. To overcome this, the first step is to eliminate snacking and return to three meals a day. Once the body has adapted to three meals without snacks, the next step is to reduce the window of time those meals are consumed within. As a first step, a person might move to a 12/12 intermittent fast in which they eat for 12 hours and fast for 12 hours. Then gradually move towards an 8/16 intermittent fasting pattern. 

Of particular importance is an understanding of the difference between psychological hunger and physical hunger.  Physical hunger happens when our body falls so low on available energy from food recently eaten that we begin to experience a calorie deficit. Physical hunger is challenging to differentiate from psychological hunger if we have been in the habit of feeding ourselves so often that we never experience physical hunger.

Complicating matters, psychological hunger is often triggered by expectations learned through habit or withdrawal from addictive foods, especially the refined SOS foods.  Learning to differentiate physical hunger from psychological hunger can be challenging unless a person follows a plant-based whole food diet.  If the transitions are challenging, you can usually make it easier by staying busy with less time to think about snacking.

While any diet could be paired with intermittent fasting, the most challenging diet will be the Standard American Diet (SAD) with its many addictive foods. In contrast, most that switch to a plant-based whole food diet for a few months before fasting finds the transition far easier.

Regardless of the diet chosen, drinking plenty of water during a fast is important. While there’s no set amount required, water should be the preferred drink. Non-calorie drinks like tea and coffee are an alternative although they should be used in moderation to limit caffeine intake. If water isn’t your favorite drink, you may be drinking the wrong kind of water. For tastier water, a water filter can make quite an improvement in the taste of tap water.  As an alternative, water infused with fruit makes water more appealing while holding close to the zero-calorie goal for drinks consumed while fasting.

While you may think of fasting as a way to lose weight, there are far more benefits. Fasting helps improve blood sugar regulation and helps cleanse the body. Another significant benefit is decreased inflammation. For a person with arthritis, this can be especially helpful. The list of benefits is impressive and includes reduced cholesterol and reduced risk for heart disease, stroke, and cancer.  Fasting can also be protective of chronic diseases like asthma, diabetes, ulcerative colitis, Crohn’s disease, neurological diseases, and other autoimmune diseases.  If the benefits of fasting could be put in a pill, it could probably replace 75% of the prescriptions I write.  Unfortunately, like walking and regular exercise, fasting also requires commitment to a lifestyle change.

Except in the case of people with diabetes or with very low body weight, short term fasting should not cause dangerously low blood sugar.  However, the type of foods eaten can have a drastic effect on the rise and fall in blood sugar.  Processed foods made from flower and sugar are usually the culprit. For anyone with a history of low blood sugar, be sure to consult a doctor before attempting a fast.  Others that should consult a doctor before attempting to fast include women that are pregnant or breast-feeding, children, those that have gastroesophageal reflux disease (GERD), cortisol regulation issues, or have an eating disorder.

Several myths surround the subject of fasting. Contrary to what you may have heard, a healthy person is unlikely to have any negative consequences from missing a few meals.  In a time of famine, a person that fails to find food for several days doesn’t wither from weakness.   If the normal body response was to collapse from weakness after failing to find food for a few days or even a week, our species would have long since passed from earth. Rather, the body’s response is to begin converting fat to energy.  Granted, for a person that hasn’t called on their fat reserves before, this can be an uncomfortable transition.  Assuming there is stored fat to convert, even a very hungry person that has been without food for days should be able to function at near peak efficiency as they continue their forage for food.  If this seems at odds with your personal experience, it’s because our bodies become conditioned to our habitual eating patterns.  As a consequence, the transition from frequent feeding to extended breaks between meals requires time for adaptation.

Another common concern is that the body might become undernourished during the period of fasting. Some worry that the body might begin robbing muscle tissue for energy in the absence of adequate food. Fortunately, this doesn’t happen during short fast, nor is it likely to be a significant factor so long as there’s adequate fat for the body to call upon for energy. For example, male athletes typically have a body fat percentage between 6% and 12%.  To remain competitive, these athletes, despite their relatively low body fat, are not converting their muscles back into an energy source. For a person below 4% body fat, fasting could be a significant problem.

Intermittent fasting has many benefits; however, it will not make amends for a poor diet or binge eating following a fast. Mindfully eating nutritious foods must be part of the regimen if intermittent fasting is to be beneficial. Fortunately, intermittent fasting has the positive effect of moderating the urge to overeat unless the choice of foods is those that are hyper-palatable.

The longest known fast was in 1971 when a 27-year-old man survived on water and supplements for 382 days and shrank from 456 to 180 pounds.  Perhaps this example clears up any fears you may have about an intermittent fast that lasts 12-16 hours. Ultimately, the type of fast that works best for you depends on your state of health, dietary habits, and the schedule you must accommodate.

When ready to make intermittent fasting part of your routine, let’s have a chat. It can be easier than you might imagine and supportive of your health in more ways than you might expect.

            Nancy Neighbors, MD

Why Fasting Can Be Challenging

Given that we evolved in a world of scarcity, any calorie deficit awakens the natural response to eat and replenish the calories. However, there is more going on that has little to do with genetic predispositions.  For example, having an expectation of having dinner at 7:00 pm, prompts the brain to begin thinking about dinner even if you aren’t physically hungry.  Food addiction also plays a part.  Many might deny food addition because they never had the urge to hold up a 7-11 for cookies or chips.  For most, their food addiction is a subtle signal that diverts attention more so than create noticeably dysfunctional behavior.

With regard to intermittent fasting, the important message is to recognize that your body will be sending signals to eat more frequently than is needed. Fortunately, most of those signals will diminish in importance as you adapt your schedule to eating fewer meals with longer periods of fasting.

While genetics plays a part, our environment often has a greater influence on how often we feel the need to eat. In controlling the environmental factors, the key is to remove foods that are triggers.  Again, this includes removing addictive foods made from refined foods, especially those with SOS (salt, oil, sugar.). Excessive salt can also be a trigger. In general, it’s best to put these foods out of sight and out of mind.

A second helpful strategy is to reduce stress levels. Hormones released as a response to stress often make us feel hungry. Sleep is also important. When you are sleep deprived, the release of certain hormones in your body produces a signal that tells you that you are hungry. The trick is to stay focused on the goal with plans that include a grocery list to guide purchases, keeping supportive foods on hand, and defined meal plans.

Fasting and Autophagy

A benefit of fasting is the boost it gives to the physiological process that supports cleaning the body (autophagy). Because our body is in a constant state of dying and being rebuilt, it’s important that the byproducts be swept away. If allowed to accumulate, these discarded parts would contribute to poor tissue health and could even lead to cancer.

During autophagy, the body marks damaged parts of cells. These damaged parts are then cleared from the body. During a period of fasting, this process of autophagy can be increased by 300 percent.

Although fasting is the most effective way to stimulate autophagy, exercise also accelerates autophagy.  This is, in part, why fasting and exercise both have been shown to be protective against cancer.

The Fasting Mimicking Diet

            A fast that allows eating but with a significantly reduced calorie intake is called the Fasting Mimicking Diet.  On the five days calories are reduced, they are limited to about 800 calories per day.  For some people, the fasting-mimicking diet is easier to follow than a day with no food.  Research has shown that on the days of reduced calorie intake, autophagy is stimulated as it is in a normal fast.  Also, just as in a normal fast, when fasting stops, the body is stimulated to regenerates new cells that promote health.

Another advantage of the Fasting Mimicking Diet over traditional fasting approaches is that it helps stimulate the loss of abdominal fat while conserving muscle and bone mass.  For more about the Fasting Mimicking Diet, the book, “The Longevity Diet,” by Valter Longo, PhD has the details. The book is available from the public library.

            The book, “The Longevity Diet,” is also available from the Prolon website for the cost of shipping.  While getting the book for the cost of shipping is a bargain, I can’t say the same for the pre-packaged meals sold by Prolon. No doubt the Prolon meals are a convenience, however, I have no evidence that they would be superior to any 800 calorie meal or snacks that you could make at home for a fraction of the cost.

            To help assure that his interest is only in the science and not in the profits from Prolon, Dr. Longo contributes all income he receives from ProLon to an independent charity.

            For an entertaining and informative story about one person’s experience with a fasting mimicking diet, read the article, “I tried Prolon’s starvation diet so you wouldn’t have to.”  Despite the articles’humor seeking title’, you will discover that the fasting mimicking diet has substantial research behind the claims made in its favor.

The Everything Guide
to Intermittent Fasting

The book, “The Everything Guide to Intermittent Fasting,” by Lindsay Boyers provides an overview of intermittent fasting in under 100 pages, which are followed by about 200 pages of recipes. While the overview information is easy to follow, informative, and covers the subject reasonably well, the recipes and nutrition advice was disappointing.  Fortunately, intermittent fasting and diets are separate subjects. Should you choose to read the book, my recommendation is to ignore the author’s recipes and diet recommendations.

Since there probably isn’t enough to say about intermittent fasting to fill a typical book, the recipes were obviously tossed in to fill the void.  As an alternative, almost any plant-based whole food cookbook will provide more nutritious recipes for beginning and ending a fast.  The book is available from the public library. 

Time-Restricted Eating

Time-restricted eating is similar to intermittent fasting.  While the two terms are often used interchangeably, they are not always the same. Although intermittent fasting has several variants that include calorie restricting days, time-restricted eating only requires a limited window of time for eating.

Time-restricted eating focuses on selecting the times to eat relative to the body’s circadian rhythm, with the fasting window positioned to allow the digestive system time to rest and better use the food we eat.  Indeed, when we eat can be just as important as what we eat.  Food that we eat earlier in the day is more likely to be consumed and not stored.  As our metabolic rate decreases with the onset of evening, food eaten late in the day is more likely to become stored fat.

The Birds and the Bee’s Revisited

            The classic birds and the bee’s story has been updated for a new age.  This time it’s more about why the birds and the bees don’t gain excess weight, why sharks have teeth, and why black widow spiders make such compelling mates, although only briefly.  If like most from my generation you missed the classic facts of life story, here is your chance to update your knowledge with information that’s more relevant in our modern day quest for love, health, and happiness. This time the story is told by psychologist Dr. Doug Lisle in a presentation called “The Pleasure Trap.” Upon following the above link you will notice that Dr. Lisle’s talk is part one of a three-part series in which Dr. Lisle provides a fascinating new perspective on how modern life can turn so many smart, savvy people into the unwitting saboteurs of their own well-being. Based upon principles from motivational psychology,  “The Pleasure Trap” lectures provide you with solutions for the challenges of keeping on a healthful course and making the most of your life.

Tahini Cauliflower Steaks with
Red Lentil Skordalia and Charred Green Beans

            I have tried quite a few cauliflower recipes and have enjoyed them all.  Cauliflower is such a versatile vegetable. With a bit of variation, it keeps dinner interesting.  This recipe from Purple Carrot is one you are sure to enjoy as will even the picky eaters at the table.

            If this is your first adventure with cauliflower steak recipes then you will discover that because cauliflower steaks are held together by the piece of stem at the base of each head, you can really only cut at most two thick steaks per cauliflower. Save the trim and serve as roasted florets.

            If new to cooking with cauliflower, consider ordering a dinner kit from PurpleCarrot.com that includes the ingredients along with helpful advice.  If ready to go it alone then click here for the recipe.

Ready for the 4th of July?

            Whether you’re celebrating at home or venturing out to the park or beach, a new Fourth of July Menu Builder from Forks Over Knives will help you create a custom lineup of festive summer eats.  Below is the lineup. Click here for the recipes

  • Grilled Corn On The Cob With Chipotle-Lime Rub – Nothing says summer like grilled corn on the cob. Add this spicy-tart rub for pure melt-in-your-mouth goodness.
  • Carrot Dogs – Grab some whole grain buns and try these delicious smoky-flavored carrot dogs. You’ll be amazed at how yummy they are.
  • Smashed Chickpea Avocado Dip – This hearty, chop-and-stir dip is great when you have hungry mouths to feed. Serve with toasted pita or tortillas.
  • Potato And Artichoke Heart Pasta Salad – In this creamy salad, potato and pasta soak up a tangy dressing, while hearts of palm and artichoke hearts add a nutty richness.
  • Peach Upside-Down Cake – Made with a blend of oat, sorghum, and almond flour, this light, luscious peach cake is a sweet summer treat that all will enjoy.

By Nancy Neighbors, MD

... Dr. Neighbors provides a blend of traditional family medicine and evidence-based lifestyle medicine in Huntsville, Alabama. When indicated, lifestyle change is recommended as the first line of therapy.

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