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In January 2018 I attended a talk by author Gary Taubes who was speaking in Portsmouth about his recent book “A Case against Sugar.” Gary is a science writer with a unique perspective about our current nutritional paradigm. He calls into question the validity of the science that established our existing nutrition model and has formed our conventional wisdom. His latest book shines a light on sugar, and how it has come to dominate the food chain and impact our health. 

Gary Taubes has written several books challenging the contemporary nutritional paradigm. These include

1.    Good Calories, Bad Calories (2007)

This book contests the premise that consuming fat is the cause of obesity and that all calories are equal. He argues the importance of the quality (as opposed to quantity) of calories, and the effect that the nutrients have on physiology (Insulin in particular). 

2.    Why We Get Fat and What to Do About It (2011)

This book expands upon this idea noting that the type of carbohydrates (i.e., simple carbs) is responsible for obesity, insulin resistance, and diabetes.

3.    The Case Against Sugar (2016)

His recent book documents how sugar has come to be pervasive in our diet and the subsequent health consequences, such as damage to the liver, obesity and metabolic syndrome.

Table Sugar

On the risk of losing you the reader, I feel compelled to add a paragraph of science. Table sugar, or sucrose, is derived primarily from cane or sugar beets. Sucrose is composed of 50% glucose and 50% fructose. Glucose is the primary driver of insulin, and because of the abundance of sugar and refined carbohydrates, insulin resistance and subsequently type 2 diabetes have risen dramatically. Fructose, on the other hand, is solely metabolized in the liver. Overconsumption of fructose leads to liver damage.

Historical Perspective

For the past 40-50 years, our government has endorsed the nutritional paradigm of a low-fat diet. Despite massive efforts to educate the public and eliminate fat in the food supply, obesity, diabetes and other metabolic syndromes have continued to rise at dramatic rates. Many now question the low-fat paradigm leading to regimes that reduce carbohydrate consumption such as the ketogenic diet. Regardless, most agree that removal of the fat has facilitated the addition of more sugar to our food. The average American now consumes 75 pounds of sugar per year equating to approximately 94 grams of sugar per day, roughly two and a half cans of Coca-Cola. This doubles the FDA recommended amount of sugar consumption. We are now witnessing the consequences to the over-consumption of sugar.

To contrast this, our ancestors only encountered fructose loads during certain times of the year when fruit crops came in (such as blueberries). Even during these times, the fiber in fruit mitigated the effects of the sugar in the fruit. That said, there is evidence that our ancestors became heavier during the time fruits were in season. Today, we have a constant influx of fructose (not bound to fiber) into our bodies causing the liver to overload. Nonalcoholic fatty liver disease is becoming prevalent in our society. Damaging the liver also affects triglycerides and lipoprotein function which can lead to coronary disease.    

Our ancestral genes conflict with the modern diet

For approximately 7500 generations, man has eaten a hunter/gatherer’s diet. In the last 40 years, we have drastically changed our diets, including the addition of an enormous amount of sugar. To illustrate how considerable this is, if a football field represents the time man has walked earth, we have drastically changed our diet the last 1/4th of an inch of that field. Our genes have not had time to adapt to a completely new diet of refined carbs/sugars and grain-based meals, all resulting in a tremendous spike in chronic illness (diabetes, autoimmune, etc.).

So where does this leave us and how much is too much?

Mr. Taubes discusses the difficulty in answering this question.

Unfortunately, this question cannot be answered with current science. In 1986 the FDA considered sugar to be safe and subsequently, no scientific studies followed. The second problem that Mr. Taubes points out is that it can take years before obesity or metabolic syndrome to present itself. Therefore, the causal relationship is less obvious.

Even the recommendation to eat sugar in moderation is flawed. Moderation, by the so-called experts, means not consuming sugar to the point where that individual gets fat or develops metabolic syndrome. This line of thinking is akin to suggesting that someone who smokes and does not get cancer is smoking in moderation.

A word about Nutritional Science. 

There is probably not a more unscientific genre than nutritional science primarily because of the difficulty performing randomized control studies.

As a thought experiment, if we could allocate one twin on a strict hunter/gatherers diet for 40 years, controlling for all the variables (i.e., sugar, refined grains, etc.), and then the other twin on the standard American diet, then we could give recommendations based on hard science. Since this is not pragmatic, we must rely on observational science. Since most processed foods contain sugar, even if we were to partition a population not to consume sugar, they would have to avoid all processed foods. If then they were healthier, could you attribute this to avoiding sugar, or could it be that they also avoided refined grains, gluten, fewer trans fats, preservatives and artificial flavoring?

The result is that scientists have to observe people and observe outcomes and then attempt to connect the dots, all along keeping in mind that although two events occur at the same time, one does not necessarily cause the other.

Rather than getting bogged down trying to determine which is the scientifically best diet, as Mr. Taubes pointed out when he spoke last month, we can merely self-experiment. We can commit to a regimen, such as reducing, limiting or eliminating sugar for a month or two and see how we feel and function. Using metrics such as endurance, pain, gut function, energy, weight and blood pressure can be useful. I also believe that defaulting to an ancestral diet (what food was available 100 years ago) is consistent with our genetic foundation.

To learn more about this topic, I also recommend Dr. Robert Lustig. His book Fat Chance dives deep into the science and consequences of a sugar dominated diet. He also has an excellent lecture that you can find on YouTube. Enter “Sugar, The Bitter Truth.”

Final Thought

Ultimately, the question of how much sugar is too much sugar is an individual choice. “we all decide what level of alcohol, caffeine, or cigarettes we ingest” Mr. Taube’s notes in his book. He goes on to say that “There is enough existing evidence for us to consider sugar very likely to be a toxic substance, and to make an informed decision about how to best balance the likely risks with the benefits.”