There are many reasons why the regulation of energy expenditure and storage in the human body is not just a matter of “calories in, calories out.” This is the first in a series of blogs on how different calories affect the human body differently, and how different bodies handle the same calories differently. I hope they are helpful.
Today, we will be talking about sugar. Sugar is a type of carbohydrate. Sugars can be monosaccharides (one unit), disaccharides (two units) or polysaccharides (many units).
Monosaccharides are already in their simplest form and can not be broken down further. Disaccharides are two monosaccharides connected together. Polysaccharides are, you guessed it, many molecules linked together.
Glucose: This is the main fuel for the human body. All other forms of sugar that we eat are broken down into glucose and every tissue in the human body is equipped to use glucose for fuel. Glucose is the most common form of sugar in plants (maybe that is why humans evolved to use it for fuel?). Glucose plus another simple sugar is what makes disaccharides.
Fructose. Fructose is also a monosaccharide. It can not be broken down further. It is the sweetest of all naturally occurring sugars. It's a type of sugar that is found in fruits, honey, and some root vegetables. Fructose can only be metabolized in your liver.
Sucrose. Sucrose is made of one part glucose and one part fructose joined together. Sucrose is naturally found in plants. Table sugar is sucrose. It's usually made from sugarcane or sugar beets. When a human eats sucrose, the bond between the glucose and fructose is cleaved, leaving you with glucose and fructose to digest (see above). Some of the leaders in the obesity medicine field make the point that when you eat sucrose, you may as well be eating fructose
Galactose. This is the third common monosaccharide. It is made up of the same elements as glucose, but they are arranged differently. Galactose is mainly found as a monosaccharide in peas.
Lactose. Lactose is the sugar naturally found in milk and dairy products. Lactose is made up of glucose and galactose. Lactose produces lactic acid, which is needed for fermentation to make yogurt and cheese. You need a specific enzyme known as lactase to break down lactose into glucose and galactose so that your body can absorb it. If you don't have that enzyme, you may be lactose-intolerant.
Maltose. Maltose is made of two glucose molecules bound together. It naturally occurs as the byproduct of breaking down carbohydrates. It's found in sprouted grains. Grains produce it when they break down starch to sprout.
Most of the rest of this article is about fructose. The important points about fructose are:
It is added to many foods.
It tastes very sweet.
It can only be metabolized by the liver, whereas glucose can be burned in the brain, muscles, and all the cells.
When you eat more fructose than you need, your liver is overwhelmed, and turns it into fat or it deposits in the liver to make fatty liver.
This leads to insulin resistance and inflammation, two key components of the “metabolic storm” of obesity.
Oxidative Damage: Fructose reacts with proteins and fats more than glucose does. This can cause oxidative damage to cells and tissues.
Increased Risk of Chronic Diseases: Long-term excessive fructose intake has been linked to an increased risk of heart disease, hypertension, and other chronic conditions.
The different types of excess weight may be why BMI does not tell the whole story about excess health risks. There are many people with normal BMI who still have increased risks of chronic metabolic disease, and also many people with high BMI who have normal metabolic health.
Conspiracy Theory or the Emperor’s New Clothes?
Much of the attention on the epidemics of obesity, metabolic syndrome, Type 2 Diabetes, and non-alcoholic fatty liver looks at fructose. Whether you believe in conspiracy theories or not, there are some very well-known and smart doctors who are leaders in the field who trace the increase of this epidemic back to the 1970s, when the low-fat diet was promoted as the best way to prevent heart disease (by lowering cholesterol?) and preventing weight gain. They show data that this is when obesity and Type 2 Diabetes started increasing in prevalence and getting worse. The theory is that when people stopped eating fat, they started eating more carbohydrates. And, not just any carbohydrates, more fructose. The theory is that fat tastes good, and it is highly satiety. In other words, it makes you feel full. It also makes you feel full for longer, in part because it slows down the rate at which the stomach empties (sound familiar, one of the things that the “new” injectable weight loss and diabetes medications do?). When fat is removed from food, the food doesn’t taste good. So, the food industry added fructose to it to make it palatable. Lo and behold, this made people buy a lot more of these foods. Another part of this “conspiracy theory”, or the real story, depending on your perspective, is that fructose is highly addictive. When people eat it, especially with certain underlying genetic causes, they don’t feel full, they want more of it. Then, a period of time later (when their sugar crashes because they got a huge insulin spike from a huge rapid influx of sugar), they feel tired and cranky (hypoglycemia, anyone), and want more. This, they say, meets all of the criteria for substance dependence. So, as Americans stopped eating fat and stopped eating whole foods they cooked at home, they were fed foods that were low fat with added fructose. So, they consume more calories which they can’t burn because fructose is only used by the liver and the typical lifestyle is more sedentary. And, this is why generations before ate eggs, butter, and bread and were overall much lower weight. Worldwide, as countries adopt the American diet, their populations show the same trend of obesity and Type 2 Diabetes increases. Is the food industry poisoning us and Big Pharma selling us the "cure"? Doctors who look at the shift of the weight curves of the population to the right, while the genetic make up of the population has not changed, as evidence that they are.
Putting the Lid on the Fire.
A Very Low Calorie Ketogenic Diet (VLCKD) has been shown to be a powerful tool in reducing excess fat in the liver while relatively preserving skeletal muscle mass. Many people find that is in a effective tool for losing weight and altering metabolism when a simple calorie deficit plan or exercise has not worked. Is this an intervention to stop the metabolic storm if you already have excess fat in your liver, white adipose tissue, and a state of insulin resistance and high inflammation? From there, can you start again with a healthier metabolism? It sure seems like it to me.
The current focus of addressing the epidemics of obesity and Type 2 Diabetes in American healthcare are pharmaceuticals that alter how humans digest carbohydrates. These medications are a good thing, but are they just addressing the tip of the iceberg?
For more information from the leaders in the field, go here.
Take Back Your Carbohydrates,
Valerie Hope-Slocum Sutherland, MD
