Sugar: Our Sweet Obsession

Written by 
  • Font Size

Hello fitness friends, look and see what health topic is raising eyebrows along with questions these days: Sugar and its possible link to obesity. According to Phillip and Jackie Mills, MD, authors of Fighting Globesity, over 30 percent of Americans are now clinically obese and 70 percent are either overweight or obese.

In a New York Times article titled ‘Is Sugar Toxic’ health investigator, Gary Taubes supports these statistics and adds the following: In 1980, almost six million were diabetic. The obesity rates, reportedly, hadn’t changed significantly in the 20 years previously. By the early 2000s, when sugar consumption peaked, statistics showed that one in every three Americans was obese, and 14 million were diabetic. Because over-consumption of sugar has been linked to these illnesses, fitness professionals, parents, coaches and children need to become more aware about the effects of sugar. Understanding sugar’s physiological effects, where it may be hiding in foods, and how to utilize it for energy can provide the tools to help avoid over-consumption. These could be effective strategies for battling the obesity epidemic. This article aims to help you answer the following questions: What is sugar and how does it affect our physiology? Is all sugar bad? Who needs to cut back and how can it be done?

What is Sugar?

Usually, when we think of sugar, we picture cookies, cakes, ice cream and breads. Sugar is the generalized name for sweet, short-chain, soluble carbohydrates, many of which are used in food. Carbohydrates are composed of carbon, hydrogen, and oxygen, and various types of sugar are derived from different sources. Check food labels to learn more about the various forms of sugar including: Glucose, fructose, Sucrose, maltose, lactose, dextrose and starches. These are all forms of sugar. HFCS (high fructose corn syrup), raw sugar and honey are also forms of sugar. Sugar is not just in candies; its can be found in many processed foods. For example, sugar can be found in a wide variety of foods such as hamburger buns, cereals, tomato sauces, dried fruit, flavored beverages and granola bars. Because sugar is hidden in many foods we buy, it’s important to understand how it affects the brain.

For some people, thinking about sugar can cause their mouth to water and increase their cravings. What happens in the brain that makes sugary foods so hard to resist? And as it correlates to obesity, does eating just a little bit of sugar make us crave more sugary foods?

What are the Physiological Effects of Sugar?

According to neuroscientist, Dr. Nicole Avena, when taking a bite of a sugary food such as cereal, the sugars it contains activate the sweet taste receptors in the brain. These receptors send signals up to the brain stem where it branches off into many parts of the forebrain, one of which is the cerebral cortex. Different sections of the cerebral cortex process different tastes: bitterness, saltiness, sourness, sweetness, and umami. From here, the signals activate the brain’s reward system. This complex system is a series of electrical and chemical pathways across several different regions of the brain. Problems could arise if over-activation of the reward systems kicks off a series of unfortunate events such as loss of control, cravings and increased tolerance to sugar.

Sugar’s Effect on Digestion and the Brain

When taking a bite of something sugary, the food travels down into the stomach and eventually into the intestines. In the intestines are sugar receptors as well. New research shows that our stomach (or gut) can taste sugar. One report found that just like the tongue, the intestines and pancreas have sweetness receptors that can sense glucose and fructose. Although not taste buds, they do send signals telling the brain that the body is full, or that the body should produce more insulin to deal with the sugar being eaten. The main circulation of our reward system is dopamine, an important chemical or neurotransmitter. There are many dopamine receptors in the forebrain. Drugs like alcohol, nicotine and heroin send dopamine into overdrive, leaving some people to constantly seek that high. In other words, they become addicted. The same thing happens with sugar.

Sugar also causes dopamine to be released, although not as severely as drugs. Now, what happens when sugary foods, instead of healthy balanced meals, are eaten? If too much is eaten, the dopamine response does not level out. In other words, eating lots of sugar will continue to feel rewarding. In this way, sugar behaves a little like a drug. This is one reason people seem to be addicted to sugary foods.

Is Sugar Toxic?

To better understand this addiction let’s take a brief look at the history of sugar. When it comes to overconsumption of carbohydrates in the form of refined sugars and high fructose corn syrup, some nutritional science doctors claim that sugar is toxic. According to Dr. David Lustig, Dr. of Endocrinology and Metabolism at the University of California at San Francisco:

“More and more of our total caloric intake come from sugar. The fat (in foods) is going down and sugar going up, and we’re all getting sick.”

During a highly visible lecture at a 2014 health conference, Dr. Lustig contends that fructose is poisonous, and is the toxic part of sugar. He argues also, that high fructose corn syrup (HFCS) has been surreptitiously added to our food supply. He points to one study that indicated in an average grocery store, only one type of bread did not contain high fructose corn syrup. According to Lustig, a glance into history may explain how high levels of sugar may have crept into our food supply. To learn more, visit:

In response to Lustig’s hypothesis, Gary Taubes, a health policy investigator followed up in a New York Times article, posing the question “Is Sugar Toxic?” Taubes makes a point on the idea of using sugar in moderation, saying:

“Sugar and high-fructose corn syrup might be toxic, as Lustig argues, but so might any substance if it’s consumed in ways or in quantities that are unnatural for humans.”

This brings us to the questions: What dose does a substance go from being harmless to harmful? How much do we have to consume before this happens? Is all sugar bad for us? To help answer these questions, it’s important to understand that all carbohydrates eventually convert to sugar in the body. Although this is true, not all sugars are bad. The National Association for Fitness Certification’s (NAFC) Nutrition Coach course explains: When consuming carbohydrates that have been derived from a whole, natural food with minimal processing, they will either support health and homeostasis or have a neutral effect, unless consumed in grossly excessive amounts.

When consuming carbohydrates from refined, processed foods, they mostly, if not always, lead to upsetting health and homeostasis. Our bodies are simply not designed and equipped to deal with them in such concentrated and imbalanced forms. Sucrose, as a refined sugar, actually falls into this category. Sucrose is simply a disaccharide (composed of a molecule glucose and a molecule of fructose), occurring naturally in many plant foods. In the amounts it naturally occurs, there is no problem with it. However, when consumed by itself or in processed foods in huge amounts, it has devastating effects on health and homeostasis.

Generally speaking, carbohydrates are looked upon as the body’s primary energy source when they are available in sufficient amounts.

As we can see, current data suggest that sugar over-consumption coincides with the current epidemics of obesity and diabetes. Perhaps this is one reason that blame has been put on sugars — particularly, sucrose and high-fructose corn syrup, for the problem. So, let’s think back to all those different kinds of sugar. Although each one is unique, every time sugar is consumed it kick-starts a domino effect in the brain that sparks a rewarding feeling. Too much sugar too often can put things into overdrive. So, yes, overconsumption of sugar can have an addictive effect on the brain. But according to a neuroscientist who studies sugar addictions and cravings, a sweet treat once in a while should not hurt most people.

From Fat-Free Craze to Carb Confusion

Carbohydrates seem to be a source of confusion for many, as is evidenced by the current low-carb craze. It’s possible that carb confusion is being created by trendy diets. So, it’s important for parents, teachers, doctors and fitness professionals to be able to effectively explain the affects of sugar and carbohydrates on the body. Many people believe they should avoid pasta, bagels, juice, bananas and sugar even if these foods are non-problematic for them. Yet, according to Nancy Clark, MS, RD, CSSD: “Most of the ’carbs are evil, fattening, and bad for you‘ hype is targeted not at athletes but to the masses of overweight, out of shape kids and adults.” So, contrary to conventional beliefs, carbohydrates are not inherently fattening. She suggests, perhaps it is excess calories, not carbohydrates that may be a contributing factor to the obesity epidemic.

So, what should be considered when determining how much carbohydrate and sugar is appropriate? The following variables should be factored in for each individual: 1. their lifestyle habits, 2. activity level, 3. metabolic rate (slow, medium or fast), and 4. specific food tolerances. When determining how much sugar is helpful or harmful, look at the individual. Consider their body’s demand for carbohydrates and sugar. Are they an athlete, consistent exerciser, light exerciser, or sedentary or obese? Consider how their body will actively utilize the provided energy source. For example, a marathon-runner would require more carbs and quick sugar than the average couch potato. The runner will be able to efficiently metabolize fast carbs such as rice, potatoes and pastas more efficiently than a person whose metabolism has been slowed, or who lives a sedentary lifestyle.

Become a Food Label Investigator

Fitness professionals, speak to your clients about what they are consuming. Share this list with them and encourage them to read food labels. Did you know that there are over 60 names for sugar? Sugar may be camouflaged as rice syrup, fruit juice concentrate, dextrin, diatase, and many more. To view a complete list of hidden sugars, you may visit, and sign up for NAFC’s June’s CEC Boost on sugar.

To conclude, when it comes to sugar and health, learn to consume mindfully. Start by becoming a conscientious food label reader. Pay attention to specific physiological and psychological responses to sugary foods. Individual biochemistry teaches us that every person’s response will be different, depending on the variables and stimuli involved. Everyone can learn these tools and use them as weapons against obesity, diabetes, as well as carbohydrate confusion. My advice is to consider swapping out your sugar ‘obsession’ for sweet treat ‘moderation’. Remember, how much carb/sugar a person should consume will depend on their specific body type. And for longer-lasting results, drop the dieting mindset and replace it with creating healthier habits—ones that will sustain and feed the body as well as the soul.


• Biba, E. 2014. Your Intestines Can Taste Sugar. Scientific American.

• Clark, N. 2014. Carbohydrates: A Bad Rap From The Media?

• McCloud, B. 2014. NAFC Nutrition Coach Foundations. Chapter 3.

• Mills, Phillip and Jackie, 2007. Fighting Globesity. Pg. 11.

• Taubes, G. 2011. New York Times ‘Is Sugar Toxic?’

• Virgin, J.J. 2012. The Virgin Diet. Pg. 140.


• Lustig, Dr. David, 2009. The Bitter Truth.

• Avena, N. 2014. How Sugar Affects the Brain.