Sugars are hiding out almost everywhere we turn, white flour and cornmeal-based products, bread, cereal, baked goodies, corn chips, etc.—line our grocery shelves. We are taught from childhood (through our trusted Food Pyramids) that if we want to experience “true health” we should consume anywhere from 6–11 servings of foods like bread, cereal, rice, and pasta.1 The question is, have we been duped?

Well when you consider that the majority of us were never designed to eat the types and amounts of carbohydrates we have become accustom to since the advent of agriculture, approximately 8000 years ago2, then the answer becomes a resounding YES!

Significant anthropological data suggests that our Paleolithic ancestors—which happened to be a lot healthier than we are today—ate a diet consisting of anywhere from: 19–35 percent protein, 22–40 percent carbohydrates and 28–47 percent fats3. And since we humans haven’t changed (biochemically) in over 40,000 years3, I would suggest that these same principles that governed our ancestor’s biochemistry still govern ours.

In today’s day and age, we seem to eat as many of the wrong types (I’ll get to that in a minute) of carbohydrates as possible. The majority of North Americans consume more than 50 percent of their dietary intake in the form of highly processed and nutrient void carbohydrates4 (like commercial breads, cereals and pasta)—the same ones responsible for robbing us of our health.5

Carbohydrates come almost exclusively from plant sources, including grains, vegetables, and fruits. In highly processed forms, carbohydrates become white flour, white sugar, corn flour, and syrups, which are used to make the breads, pastas, cookies, and sweets we love so much. We often hear people talk about simple carbs and complex carbs, but do they really understand the difference between them as well as which ones to avoid?

  • Complex carbohydrates are referred to as polysaccharides (long chains of sugar molecules bonded together) and are found in foods like fruits, vegetables, legumes (peas and beans), and grains (bread, pasta and rice). Some complex carbohydrates are also referred to as dietary starches. These are mostly from the grain family (including cereals, breads, pasta, oats, wheat, rice and corn), but are also found in some vegetables like potatoes and legumes. The complex carbohydrates from the fruit and vegetable kingdom were the ones that made up the majority of carbohydrates consumed by our ancestors.
  • Simple carbohydrates are just that, the simplest form carbohydrates come in. These are found as either single sugar molecules referred to as monosaccharides, (i.e. glucose, fructose or galactose) naturally occurring sugars found in most fruits, honey and milk, or double sugar molecules referred to as disaccharides (i.e. sucrose, maltose and lactose). The majority of disaccharides come from man-made processed sugars and should be avoided at all costs.

Do we actually need them?
Even though I believe that to perform at peak efficiency—and to ensure the body has a sufficient supply of phytonutrient antioxidant protection—we should never be without an ample amount of vegetables (and some fruits), the truth is that the human body does not necessarily need carbohydrates to survive.

This is due to a well-known biochemical process we have evolved with called gluconeogenesis, which refers to the creation of carbohydrates (glucose) from other noncarbohydrate sources like protein and fatty acids). Perhaps this is one of the reasons the National Research Council has never established an RDA (Recommended Daily Amount) for carbohydrates.

Every organ—with the exception of your brain at certain times—and every muscle in your body can operate at peak efficiency on by-products of fat metabolism called ketones.6 When the body does not have enough glucose, it is forced to use body fat for the majority of its energy needs and ketones are produced to fuel the body during these times. This is one of the ways in which low-carb diets propel fat loss, by forcing the body to use its own fat reserves for fuel. Research shows that once blood sugar levels are lowered for approximately three days, the brain will get at least 25 percent of its energy from ketones7 and this number will go up substantially if the body is deprived further of sugars.

It is important to understand that your body can use only a set amount of glucose to generate immediate fuel. When it can’t use sugars from dietary carbs immediately, the body stores them for future use in the form of long chains of glucose molecules called glycogen. The body’s glycogen containers are found in two areas: the liver and the muscles. The glycogen stored in the muscles is used as energy for the body but is virtually unavailable to the brain. Only the glycogen stored in the liver is accessible—through the bloodstream—as a backup source of brain food.

Whether you are lean or clinically obese, you only have the ability to store 300 to 400 grams of carbohydrate as muscle glycogen and another 90–110 grams as liver glycogen—the equivalent of about two cups of pasta or a couple of candy bars.8 Liver glycogen is so limited, that it can easily be used up within ten to twelve hours of normal activity. But during strenuous athletic activity it can be depleted as much as 3–4 times that of regular activity. The average bloodstream of a non-diabetic human has no more than one tablespoon of glucose at any given time.

Carbs and Body Fat

In today’s world, the average non-athlete consumes more carbohydrate energy then their body’s can either burn or store as short term energy—glycogen. We live in a society where the average citizen consumes 156 pounds of sugar per year9, which is the equivalent to approximately half a pound per day, and the Centers for Disease Control presented a paper showing that sugars equate to an extra 440 calories per day10—yikes! By over consuming carbs, we ensure that our liver and muscle glycogen tanks are always full. This would be a good thing if you were an athlete who needs full glycogen reserves, but for an average person it can spell disaster.

Any ingested sugars over and above what the body can use immediately or store as glycogen are converted into fatty acids—and eventually stored within your 30 billion fat cells— with the aid of the metabolic hormone insulin.11

Insulin is secreted from our pancreas after we eat and following periods of elevated blood sugar. Under optimal conditions (i.e. the caveman diet), insulin is the body’s friend. It deposits extra blood sugar (glucose), along with amino acids (protein), in muscle so that we can move and function. It also synthesizes chemical proteins for building enzymes, hormones, and muscle.12

Insulin, however, is especially sensitive to dietary carbohydrates, which are metabolized quickly into sugar. When insulin is stimulated in great quantities—as in a processed carbohydrate meal—it stimulates a powerful enzyme called lipoprotein lipase or LPL, which promotes fat storage and also prevents fat from being released from the fat cells.13 Understanding that high insulin levels equate to excess body fat, can give you the knowledge to keep your 30 billion fat cells from growing exponentially.

So in order to free up the fat so that it can be burned in the muscle cells, you’ve got to lower your insulin levels. We can do that by exercising properly and eating in harmony with our genetic structure—in other words, by eating like our prehistoric ancestors.

    References:
  1. America: Drowning in Sugar” Experts Call for Food Labels to Disclose Added Sugars. Center For Science in The Public Interest issue date (1999).
  2. Eaton, S.B, et al. “An Evolutionary Perspective Enhances Understanding of Human Nutritional Requirements.” J of Nutrition 126 (1996): 1732–40.
  3. Cordain L, et al. J. Plant-animal subsistence ratios and macronutrient energy estimations in worldwide hunter-gatherer diets. Am J Clin Nutr 2000; 71: 682–92.
  4. Simin L. Intake of Refined Carbohydrates and Whole Grain Foods in Relation to Risk of Type 2 Diabetes Mellitus and Coronary Heart Disease. J Am Coll Nutr August 2002 vol. 21 no. 4 298-306
  5. Yudkin, J. “Evolutionary and Historical Changes in Dietary Carbohydrates.” Am J Clin Nutr 20, No. 2 (1967): 108–15.
  6. King, MW. Oxidation of Fatty Acids. themedicalbiochemistrypage.org, LLC. 2013
  7. Hasselbalch, SG, et al. “Brain metabolism during short-term starvation in humans. Journal of Cerebral Blood Flow and Metabolism (1994) 14 (1): 125–31.
  8. Felig, P, Wahren, J. Fuel homeostasis in exercise. N Engl J Med 293(21): 1078-84, 1975.
  9. Well FA, Buzby JC. Dietary Assessment of Major Trends in U.S. Food Consumption, 1970-2005. United States Department of Agriculture. Economic Information Bulletin No. (EIB-33) 27 pp, March 2008
  10. Ervin RB, et al. Consumption of Added Sugar Among U.S. Children and Adolescents, 2005–2008. Centers for Disease Control and Prevention. Number 87, February 2012
  11. King, B.J. Fat Wars: 45 days to Transform Your Body. Toronto: Macmillan, 2002.
  12. Patterson, C.R. Essentials of Biochemistry. London: Pittman, 1983.
  13. Taskinen, M.R., and E. Nikkila. “Lipoprotein Lipase of Adipose Tissue and Skeletal Muscle in Human Obesity” Metabolism 30 (1981): 810–17.