Posts Tagged ‘leptin’

Sugar Substitutes

October 12, 2013

Andrew Siegel, M.D.  Blog #123

For many of us who have a “sweet tooth,” sweet tastes are delightful and we actively seek them out in accordance with our evolutionary drives. The first bite of that sugary Cinnabon is pure bliss. The brain’s reward pathway squirts out the neurotransmitter dopamine and we get a jolt of near ecstasy—the mind-body connection in action. Hopefully, within a matter of minutes, leptin—our satiety hormone that regulates appetite—will counteract the dopamine, making subsequent bites less rewarding and stopping us from gorging.

Sugar is ubiquitous in our diets, not just in the places you expect it, but also “stealth” sugar in breads, crackers, pretzels, chips, salad dressings, sauces, etc.  If you read food labels you might be shocked about the presence of sugar in many unexpected destinations. Sugar (sucrose) is clearly unhealthy and processing and refinement “advances” have permitted its consumption in unreasonable, immoderate and unwarranted amounts, contributing to America’s expanding waistlines and derrières.  So what’s the skinny on sugar substitutes?  Are they helpful in terms of losing weight? Are they better for our dental health than sugar? Are they helpful for diabetics?  Do they have risks?

Sugar substitutes duplicate the sweetness of sugar, but without the caloric (energy) load. Natural sugar substitutes originate from nature and include the following: agave nectar; date sugar; fruit sugar concentrate; honey; maple syrup; and molasses. Synthetic substitutes are concocted by chemists in a lab and are known as artificial sweeteners.   There are 6 “super-sweet” high-intensity substitutes approved for use by the FDA. The super-sweet sugar substitutes are the following: stevia (Truvia); aspartame (NutraSweet; Equal); sucralose; neotame (manufactured by the NutraSweet company); acesulfame (Nutrinova); and saccharin (Sweet’N Low).  Aspartame is the most popular artificial sweetener in United States and sucralose is not far behind.

Sugar substitutes are widely prevalent in our food supply—in processed foods, baked goods, dietary foods, dietary soft drink beverages, powdered drink mixes, canned foods, jams and jellies, dairy products, toothpastes, chewing gums, sugar-free desserts such as ice cream, yogurts, and puddings, and in vitamins and medicines including cough drops.

In terms of weight loss, sugar substitutes can be an effective and attractive means of consuming less calories since the substitutes are non-nutritive and have virtually no calories, while retaining the sweet taste of food substances.    This is in contrast to sucrose that has 4 calories per gram.  Additionally, sugar substitutes are dental friendly, as they—unlike sucrose—are not fermented by the bacterial flora that lives on the teeth and thus do not produce acidy waste products that cause tooth decay.   Sugar substitutes can be effective for diabetics who have trouble regulating blood glucose levels since sugar substitutes do not elevate blood sugar levels the way sucrose does.

Sugar substitutes, while providing a sweeter taste than sugar, contain few or no calories, which is why using them has been thought to aid weight management. Our food-reward system plays a critical role in regulating eating behavior and controlling the number of calories consumed. When the tongue perceives sweetness, the brain expects a glucose infusion, which increases levels of dopamine and stimulates reward centers in the brain.  Without the energy kick provided by actual sucrose, sugar substitutes cannot fool our brains into feeling satisfied. Sugar imposters yield no such reward and cravings can persist and cause more rebound consumption than eating sugar in the first place.

The Food and Drug Administration (FDA) is the governmental body responsible for the regulation of sugar substitutes. Over the years, health concerns have been raised with respect to the use of substitutes and they have been the subjects of intense scrutiny. The general consensus is that there is no sound evidence that any of the substitutes approved for use in the United States cause serious health problems and that they are generally safe in limited quantities. However, there is ongoing and unsettled controversy regarding whether substitute usage is problematic in terms of health risks. We remain muddled in a debate about the health implications of substitutes and whether they might be linked to obesity, cancer, Alzheimer’s disease, ADD, autism, etc.  Search on the Internet and you will learn about the “conspiracy theories” concerning artificial sweeteners.

Saccharin (Sweet’N Low) was the first artificial sweetener, originally synthesized in 1879.  It is 400 times as sweet as sugar.  Although saccharin was previously considered hazardous when it was discovered to cause cancer in rats and carried a warning label, the warning label was subsequently repealed and saccharin has been removed from the hazardous list.  Cancer in laboratory rats has not been found to necessarily correlate with cancer in humans.

Aspartame (Equal; NutraSweet) was discovered serendipitously in 1965 when a scientist at Searle was working on a drug for peptic ulcer disease and spilled some of the chemical on his hand. He accidentally noted its sweet taste, and the rest is history.  It is 200 times as sweet as sugar and derives from 2 amino acids, aspartic acid and phenylalanine.  It is undesirable as a baking sweetener because, when heated, it breaks back down into its constituent amino acids.  It has sometimes been linked to headaches.

Stevia is a natural sweetener that is derived from the stevia plant; its leaves have been used as a sweetener in South America for centuries. It is 300 times as sweet as sucrose.  It was discovered by botanist Petrus Jacobus Stevus, which is why it was named Stevia.

Sucralose (Splenda) is a chemically modified form of sugar that was discovered in 1976 and is about 600 times as sweet as sucrose. It is stable when heated, so is appropriate for use in cooked foods.   Most of consumed sucralose passes out of the body unchanged, with only a small amount getting absorbed.

Neotame (from NutraSweet) is chemically similar to aspartame, but is significantly sweeter, being the sweetest of the group.  It is the only artificial sweetener deemed safe by the Center for Science in the Public Interest (CSPI).

Acesulfame is calorie-free and 200 times as sweet as sucrose; it is formed by adding potassium to aceto-acetic acid.  It is not metabolized by the body, but is excreted unchanged.  Because it is heat stable, it can be used in cooking and baking.

Sugar alcohols are carbohydrates that occur naturally in certain fruits and vegetables, but can also be synthesized.   They do contain calories but they are lower in calories than sucrose. They are used in many processed foods and household items including chocolate, candy, frozen desserts, chewing gum, toothpaste, mouthwash, baked goods and fruit spreads.

Bottom Line: The take-away message is “everything in moderation.” Whether you indulge in items sweetened with sugar derived from sugar beet or sugar cane, sugar alcohols, or any of the natural or artificial sweeteners, consumption should always be kept in check.

Andrew Siegel, M.D.

Author of Promiscuous Eating: Understanding and Ending Our Self-Destructive Relationship with Food:

Available on Amazon in Kindle edition

Author of: Male Pelvic Fitness: Optimizing Sexual and Urinary Health, in press. Will be available in e-book and paperback formats in later 2013.

Blog subscription: A new blog is posted every week.   On the lower right margin you can enter your email address to subscribe to the blog and receive notifications of new posts in your inbox.  Please avail yourself of these educational materials and share them with your friends and family.


“Hurt” Your Hunger

July 13, 2013

       Andrew Siegel, MD Blog #112

Hunger is one of our most basic and primal urges and a fundamental part of our hard-wired engineering in order to ensure adequate intake of calories, energy, and nutrition for the purpose of survival of the individual.  It is one of nature’s clever “bait and switch” mechanisms: we think we are satisfying an urge, but we are really fueling up to stoke our metabolic processes and provide fodder for cellular growth and maintenance.

Hunger is functionally based upon chemicals including hormones and neurotransmitters—for example, ghrehlin (appetite stimulating), and leptin (appetite inhibiting).  Additionally, our circadian biorhythm plays an important role as our brain’s body clock drives the cycle of hunger which is typically at its lowest at 8 AM in the morning and peaks at 8 PM at night.  This cycle can lead to a tendency to gain weight by not eating when you need it (breakfast) and eating when you don’t need to (evening after dinner).  Furthermore, emotional factors—particularly stress—can impact our “hunger” in a major way.  Our environment—which can expose us to the sight, sound, and smell of food, television commercials and other triggers—also has a significant influence on our hunger, causing us to suddenly desire food when moments before we had no appetite whatsoever.

It is important to make the distinction between physiological hunger and emotional hunger.  Physiological hunger is the instinctual drive to seek food versus emotional hunger, which is psychological and largely influenced by environmental exposure to food triggers as well as to our emotional state of mind.  If you haven’t eaten for hours and are famished and have a stomach that is producing a symphony of growling sounds, it is a pretty clear-cut case of physiological hunger. However, if you have just eaten dinner and are sitting on the couch relaxing in front of the television and become “hungry,” typically for a very specific food item, it usually bespeaks emotional hunger.

Interestingly, our physiological hunger drives us to consume a fixed weight of food every day, regardless of calories/nutrient content; therefore, low-caloric density foods—those that contain abundant water content—rule. For this reason, it is good to “preload” before a meal by eating low density foods such as salad, soup, a piece of fruit, cut-up raw veggies or drinking a glass of water to help curb caloric intake.

Fatigue eating is a very common phenomenon, which has a physiological basis.  This is why a good night’s sleep goes a very long way in helping to maintain a healthy weight. It is important to not succumb to the temptation to eat yourself awake—see my blog on FATigue eating:

The nutritional content of our meals is of fundamental importance in quelling our hunger. Specifically, eating protein as well as some healthy fats can go a long way in diminishing our hunger. A diet that is balanced in terms of carbohydrates, proteins and healthy fats can keep one satisfied until the next meal.  So, try to have some protein for breakfast as well as for an afternoon snack— it does wonders in terms of maintaining high levels of our satiety hormones to keep hunger at bay.  Carbohydrates without protein or fat provide only a short-lived suppression of hunger.

Stress is a particularly toxic emotion in terms of driving “hunger.”   It is best to try to avoid “eating” stress away and instead trying to “exercise” it away.   Exercise has numerous positive effects, including the enhancement of the brain’s executive function to help inhibit temptations and impulses—see my blog on Exercise To Exorcise: Like fatigue, there is a clear-cut physiological basis for stress- induced eating.  Stress causes the release of a number of hormones and chemicals including cortisol, which can profoundly influence us to eat, often fatty, salty, and sugary foods—see my blog on The Mind-Body Connection and How It Relates To Our Eating Behaviors:

Bottom Line: Exercising “mindfulness” is a vitally important asset in the struggle to maintain a healthy weight. It is a good idea before putting any food item into one’s mouth to consider what you are eating, why you are eating, when you are eating and where you are eating.  If what is a bad what, why is for non-physiological reasons, when is late at night and where is in front of the TV or in the car while driving, it is worth considering an alternative activity to occupy and amuse yourself in lieu of eating. Am I saying it is bad to sit in front of the television and have a snack?  Not at all…but if you are really not hungry and just desire entertainment and diversion, it is best not to down a large bag of chips mindlessly. Consumption should be accompanied by conscientious choices.

Andrew Siegel, M.D.

Author of Promiscuous Eating: Understanding and Ending Our Self-Destructive Relationship with Food:

Available on Amazon in paperback or Kindle edition

Blog subscription: A new blog is posted every week.   On the lower right margin you can enter your email address to subscribe to the blog and receive notifications of new posts in your inbox.  Please avail yourself of these educational materials and share them with your friends and family.

Sleep To Slim

July 20, 2012

Andrew Siegel, M.D.      Blog # 67


On many levels, sleep has a vitally important role. Our brains and bodies require this critically essential down time to “recharge.” Our sleep cycle includes restorative deep sleep phases and rapid-eye-movement sleep phases.  Our bodies need sufficient time to complete all phases of sleep to maintain our well being and to promote tissue repair, memory reinforcement and the release of hormones that function in regulating growth and appetite.

Who does not relish the blissful experience of a great night’s sleep, in which we awaken feeling alert, rested, energetic, optimistic and ready to tackle life with vigor? Throw in some great dreams and we have the recipe for the beginning of a wonderful day. Conversely, we have all experienced a very poor night’s sleep, in which we awaken feeling physically exhausted, mentally spent, lids heavy, dark circles under our eyes and in a disassociated state, totally unprepared and unenthusiastic about facing the new day.

Many of us do not realize the profound association between sleeping and eating.  The bottom line is that an adequate amount of quality sleep helps keep us on the healthy eating wagon, while insomnia and chronic sleep deprivation can throw us off it.  Fatigue eating is a very real phenomenon and is one of the circumstances that drive my own bouts of mindless, unnecessary eating.  Many of us, when physically and mentally exhausted, in a “zombie”-type state, often seek refuge in the refrigerator or pantry in spite of not being genuinely hungry. It seems that this FATigue—an altered state of mind and body—would best be served by seeking refuge napping in our beds, but mindless food foraging all too often serves as a surrogate activity.

In addition to the dis-inhibition of “eating discipline” that occurs with fatigue (similar to that which occurs with alcohol), there appears to be a physiological basis for this fatigue-driven eating. Fatigue or sleep deprivation causes the following:

  • decreased levels of leptin, our appetite suppressant
  • increased levels of ghrelin, our appetite stimulant
  • increased levels of cortisol, one of the stress hormones
  • increased  glucose (blood sugar)levels

Thus, fatigue results in internal chemical changes that can drive our eating.

Acute sleep disruption is associated with increased appetite and caloric intake and chronic sleep deficits result in an inability to be attentive and focused, interfering with our mindfulness, which can wreak further havoc with our eating.  The disassociated “zombie” state lends itself to dysfunctional eating patterns and, as such, weight gain is a predictable consequence. Additionally, a chronically fatigued state will also affect our ability to exercise properly, if at all.

The following are pointers to help achieve a good night’s sleep:

  • A quality mattress and box spring, topped by a cushioned mattress pad, are wonderful investments since we spend up to one-third of our lives sleeping; amortized over many years, they really prove quite a bargain.
  • Same goes for pillows—some like them firm, some fluffy, so you must find what works best for you.
  • Try to maintain a regular sleep schedule in terms of time going to sleep and time arising, making an effort not to disrupt the pattern too much on weekends.
  • Caffeine restriction after a certain hour, depending on the individual—this means coffee, tea, colas, and chocolate (which contains a caffeine-like chemical).
  • Limit daytime naps.
  • Don’t overdo it with alcohol during dinner and the evening hours; even though alcohol acts as a central nervous system depressant (which one might think would aid in sleep), in reality, it interferes with our natural sleep rhythms.
  • Easy on late-night eating—going to bed bloated with churning intestines is counter-productive in the effort of getting quality sleep.
  • Don’t overdo it with fluid consumption in the evening that can cause sleep-disruptive nocturnal urinating.
  • Exercise early since evening exercise tends to stimulate our brains and bodies and cause insomnia.
  • Keep your bedroom at a comfortable temperature—generally, a cool room promotes quality sleep.
  • Keep the room as dark as possible—black out shades are terrific.
  • Try to keep the ambient noise to a minimum so the sleeping environment is quiet.
  • For some, white noise can be very helpful—I go to sleep to the sound of machine-generated surf; not quite as good as when I lived in Manhattan Beach, California right on the ocean, but helpful nonetheless.
  • Have a pre-sleep relaxation and tension-reducing ritual such as reading, a hot bath, meditation, romance, etc.

Take home points:

— The fatigue resulting from insufficient sleep interferes with our mindfulness and can result in unnecessary eating as a surrogate activity for sleeping.

— There is a biochemical basis for this sleep-deprivation eating.

— When we find ourselves succumbing to fatigue eating, it is best to try to muster up the wherewithal to head to the bedroom instead of the refrigerator—we will feel much better about ourselves in the morning and will have saved ourselves needless calories!

— On a general basis, it is best not to use eating as a substitute for other activities.

—  Try to consistently get enough sleep in order to avoid FATigue and its many pitfalls!

Andrew L. Siegel, M.D.

Author of Promiscuous Eating: Understanding and Ending Our Self-Destructive Relationship with Food

Available on Amazon Kindle

Losing Weight: Hard…Maintaining Weight Loss: Grueling!

January 7, 2012

 Blog #41  written by Andrew Siegel

Kudos to Tara Parker-Popes for her NY Times Magazine article entitled “The Fat Trap.”

Bottom line: As we lose weight, our bodies change in terms of hormones and metabolism.  This biochemically-altered state persists after weight loss, spurring our appetite and ultimate renewed weight gain.  Thus, maintaining weight loss is an intense struggle in which we have to combat not only hunger and cravings, but also our body’s powerful internal drives.

After weight loss, ghrelin  (the hunger hormone that drives eating) rises from pre-weight loss levels, and leptin (the satiety hormone that suppresses hunger and increases metabolism) decreases from pre-weight loss levels.  Additionally, a number of other hormones associated with appetite and metabolism change and remain altered from pre-weight loss levels.  In essence, weight loss induces a unique metabolic state that causes a biochemical imperative to eat and regain weight.

Essentially, the body rebels against the weight loss long after the dieting has stopped.  This helps explain the sobering truth that once we become fat, most of us will remain fat. That stated, there are those who, in spite of biochemical forces that are obstacles, successfully achieve and maintain a normal weight after weight loss.

In addition to the internal biochemical imperative for weight gain after weight loss, our external environment aggravates the problem. We live in a culture where eating plays an enormously prominent role.  In our food-obsessed and food-centric society, it is very difficult, if not impossible, to avoid food cues and eating opportunities over the course of the day.  Our culture has reinforced using food for reasons that have no relationship to nutrition and energy, particularly when we eat for emotional reasons, ranging the gamut from reward-eating to stress-eating to boredom-eating.

Weight loss is not an easy task—we all know that pounds go on easily, but come off with great effort that involves fewer calories in and more calories out through exercise.  Many people are not successful at losing weight, although those who are truly disciplined can succeed.  Of those who do lose weight, most will ultimately regain the weight because of this combination of internal and external factors that conspire to thwart our best efforts.  These factors are so powerful that in order to overcome them to allow the weight loss to be permanent, a lifelong modification in our relationship with food must occur.  It is possible, but demands a dramatic change in mindset in order to resist our own internal biochemical imperative and the external “hostile” food environment.

Andrew Siegel, M.D.

Author of Promiscuous Eating: Understanding and Ending Our Self-Destructive Relationship with Food

The Mind-Body Connection: How it Relates to Our Eating Behaviors

December 31, 2011

 Blog # 40

(Much of the following first paragraph is excerpted from the December 29, 2011 obituary of Dr. Robert Ader, written by Paul Vitello and published in The New York Times.)

Dr. Ader was an experimental psychologist who was among the first scientists to show how mental processes influence the body’s immune system, a seminal discovery that changed modern medicine.  You might say that he was the father of the “mind-body” connection.  His research was a touchstone for studies that have shown the communication network among immune cells, hormones, and neurotransmitters.  This field—psychoneuroimmunology—provides the science behind notions too often considered “magical thinking”:  that meditation helps reduce arterial plaque; that social bonds improve cancer survival; that people under stress catch more colds; and that placebos work not only on the human mind, but also on cells themselves.  Dr. Ader demonstrated that stress worsens illnesses, sometimes even setting them off, and that stress reduction is essential to health care.  To summarize Dr. Ader’s work in one phrase: Stop worrying or you’ll make yourself sick.

The fact that mental processes affect the immune system, hormones, and neurotransmitters has a profound influence on our eating behaviors.  An understanding of our mind-body relationship is fundamental in the effort to conquer eating issues.

Carly, age 40: “When I am stressed or have things on my mind or I am really tired, I eat sweets, like cakes and cookies. I don’t even give it any thought. I feel bad after and think about eating better or exercising, but I don’t act on these thoughts.”

Although it is convenient to think of our minds and bodies as separate and discrete entities, our emotional and cognitive sides do not exist independently of our flesh and physical beings. Our minds and bodies are very much commingled, and our mind-body connection is extensive. Our bodies house our minds, and our minds control our bodies, but our minds are made of matter just as our bodies are, and our bodies have a vast array of neural networks running through them that essentially are peripheral extensions of our minds. When our minds are unhealthy, often our bodies become unhealthy, and vice-versa. Optimal human functioning and performance requires a coordinated and harmonious relationship between our minds and bodies.

The following are a few examples of the mind-body connection:

When you become embarrassed your cheeks get a crimson flush.

When you are driving and the car in front of you comes to a sudden and unexpected stop, you respond by slamming on your brakes and just miss a rear-ending collision, your heart races, your pupils dilate and your breathing pattern is rapid and deep. 

When you are fatigued after a hard day of work but can muster up the fortitude for a workout, you can emerge physically and emotionally invigorated, stress relieved, fatigue washed away—refreshed with a wonderful feeling of well-being.

The above examples show how our minds can affect our bodies—blood flowing to our face in the blush response and the classic physiological stress response; and how the body can affect the mind—physical exercise transforming an emotional state. The essence of the mind-body connection is that our thoughts, feelings and emotions can affect our body chemistries and cause a physical response, and conversely, our physical actions, like exercise or laughter, can influence our brain chemistries and affect our thoughts, feelings and emotions.

How is the mind-body connection relevant to eating?

We are highly emotional creatures and it these feelings that are one of the key features that separate us from other members of the animal kingdom. We bring our emotions to every situation, and on a certain level we are all emotional eaters since we all bring our emotions “to the table” in this sense. It is impossible to separate emotions from eating and, with this in mind, it becomes easier to understand how our emotions can cause unhealthy eating patterns.

There are wide ranges of emotions that can trigger eating. Exhaustion, stress, boredom, anxiety, anger, loneliness, sadness, depression, frustration, resentment, disappointment, issues of self-esteem, and interpersonal conflicts are some of the negative emotions that can drive eating. Positive emotions including hopefulness, happiness and confidence can also spark emotional eating. In general, it appears that negative emotions demand neutralizing and positive emotions fuel our passion for eating. There are many among us who use food as a refuge from negative emotions, and for whom food serves as both a “friend” and “therapist”; however, there are certainly, some of us who turn off from eating under the same circumstances. Thus, there is a wide range of eating responses to emotions and all of us “metabolize” our feelings differently.

Stress seems to be our most compelling emotional drive to eat, second only to hunger as a motivation to eat. It is the rare person who does not lead a stressful existence. Stress seems to pummel our souls and eating serves as a mechanism to sooth our beaten-up inner beings— a means of distracting us from our troubles and escaping from the real-life problems and unpleasant aspects of our daily lives.  Life can oftentimes be very tough and food can provide an immediate source of comfort and relief, just as a cigarette can to a smoker or alcohol to a drinker. Many of us, particularly after a very stressful day, head straight for the refrigerator after arriving home from work, seeking solace, refuge and sanctuary.

Interestingly, it seems that when we eat for negative emotional reasons we tend to gravitate to unhealthy foods—it would appear that we desire the kind of foods that will match the emotion driving the eating. Self-destructive emotions beg for self-destructive eating behaviors and self-destructive foods.

In accordance with the work of Dr. Ader, there is a biochemical explanation for stress eating. The adrenal gland hormone cortisol—released in response to stress—can stimulate our appetites and cravings for sugar.  This is the very reason people on corticosteroid medications tend to have enormous appetites, gain weight, and have a tendency for obesity. Cortisol also functions to reduce the satiety hormone leptin, further stimulating our appetites. Additionally, the consumption of certain foods, especially those containing sugar and fat, can cause release of endorphins that are powerful morphine-like chemicals with pain-relieving properties. Is it any wonder that food serves a role as a sedative?  It is of great interest to note that exercise can also release large amounts of these endorphins, so better to head to the gym than the fridge when stressed!

In summary, our emotional state—in a constant state of flux—affects our neurotransmitters, hormones and immune cells.  The variable state of our internal biochemical environment that occurs in response to our emotional state is capable of profoundly influencing our behaviors, including eating. In spite of the biochemical imperative to eat driven by certain emotions, understanding the influence of the mind-body connection is one of the first steps towards overcoming unhealthy eating patterns.

A healthy and sunny 2012 to all!

Andrew Siegel, M.D. for more info on my book: Promiscuous Eating: Understanding and Ending Our Self-Destructive Relationship With Food