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Published: August, 2013; Vol 10, Num 3


Getting Your BMI in Shape (Part II)

Dietary Habits That Make a Difference

In part I of our series, we looked into body mass index (BMI), calories, exercise and fat in our diet. Now, in part II, we examine the role of sugar and carbohydrates. Next, we will report on antioxidants and the combined impact of sugar and fat. In the final part, we will recommend dietary habits for life.

What is the newest information about sugar?

The term "sugar" usually refers to table sugar – sucrose – but is composed of equal parts of two more basic sugars, glucose and fructose.

Glucose is what every cell in your body burns to provide the energy it needs to do its job. While glucose has always been an important part of human diets, sucrose is a relatively new addition. In pre-industrial (agricultural) societies, with grain crops providing plenty of glucose, it is estimated that sugar consumption was about 12 pounds per year. Even in industrial countries like Japan and Korea today, dietary sugar intake remains insignificant. Not so elsewhere. With the development of mass produced food products in Europe and the U.S. in the late 1800s, sugar was added to spur consumption, and around 1900, candy and soda became broadly available. Between 1900 and 1920, per capita sugar consumption almost doubled. Today, the USDA estimates that each American consumes 156 pounds of added sugars per year.


Sucrose: Commonly known as table sugar or simply "sugar," sucrose is typically granular and white. It is usually processed from sugar cane or sugar beets. It is half fructose and half glucose.

Fructose: The sweet ingredient in fruit and other plants, fructose is a simple monosaccharide.

Glucose: Not so starkly sweet as fructose, glucose is also a simple monosaccharide found commonly in many plants and concentrated
in carbohydrates such as rice, potatoes, corn and bread.

According to the latest research (reviewed in a video here), the fructose in sugar is toxic to human bodies when it is ingested in high dosages. Like other toxins, fructose is processed by the liver, but in sudden, high dosages, the liver can be overwhelmed. When that occurs, it converts what it cannot eliminate into fat, creating a "fatty liver" which induces a condition known as insulin resistance. Insulin is a hormone produced by the pancreas and secreted to keep blood sugar in control after a meal (and, in particular, after eating carbohydrates). Without it, blood sugar levels spike and then fall sharply, producing an unnecessary and inappropriate desire to eat more food to restore the sagging glucose. In people who develop insulin resistance, the pancreas pumps out more and more insulin but cannot control blood sugar. Eventually, it suffers “pancreatic exhaustion.” Blood sugar rises out of control, and diabetes sets in. Also, feeling the need to eat, these people often eat too much and become overweight or obese.

Not everyone with a fatty liver is a fat person (though many are). Some lean people have fatty livers, and they often develop diabetes, unusual in people who are not obese. Genetic predisposition is also a factor, but today's massive (and unnatural) consumption of fructose may be the main culprit.

Because fruit has always been part of people's natural diets, we can be confident that our bodies can handle a certain amount of fructose. We don't have to completely eliminate sugar from our diets, but we need to scale back toward a more natural level.

What is the newest information about carbohydrates?

Over the last two decades, as low-fat dieting failed to stem the growth of North American waistlines, carbohydrates – rice, wheat, corn and potatoes, also known as starches – came under increasing scrutiny. Carbohydrates provide glucose, the fuel for our cells' work. Glucose is stored in the body as fat.

These grains and potatoes – in their whole form with husks, kernels and skins intact – have long been part of human diets. However, given the active lifestyles of earlier generations, the build-up of fat was a slow and limited process. It was only after the advent of commercial food processing around 1900 that white rice, white flour, corn syrup and other processed carbohydrate products entered our diets. And the increasing prevalence of sedentary work has aggravated the problem.

Although, today, the Atkins Diet is widely snubbed for its failure to limit fat intake, its emphasis on reducing carbohydrates, particularly the processed varieties, is widely embraced.

Try to shift the carbohydrate balance in your diet toward whole grains. Keep in mind that many processed food makers bulk up their products with carb-based gums, gels and other additives. Read the labels and avoid those heavily loaded with non-natural and carb-based ingredients. One additive worth special note is high-fructose corn syrup (HFCS), a corn-based sweetener whose fructose level is commercially boosted to 60 percent. As much as possible, it should be avoided.

Next month: antioxidants and the combined impact of sugar and fat.

[Steve Clark]