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:
- America: Drowning in Sugar” Experts Call for Food Labels to Disclose Added Sugars. Center For Science in The Public Interest issue date (1999).
- Eaton, S.B, et al. “An Evolutionary Perspective Enhances Understanding of Human Nutritional Requirements.” J of Nutrition 126 (1996): 1732–40.
- 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.
- 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
- Yudkin, J. “Evolutionary and Historical Changes in Dietary Carbohydrates.” Am J Clin Nutr 20, No. 2 (1967): 108–15.
- King, MW. Oxidation of Fatty Acids. themedicalbiochemistrypage.org, LLC. 2013
- Hasselbalch, SG, et al. “Brain metabolism during short-term starvation in humans. Journal of Cerebral Blood Flow and Metabolism (1994) 14 (1): 125–31.
- Felig, P, Wahren, J. Fuel homeostasis in exercise. N Engl J Med 293(21): 1078-84, 1975.
- 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
- 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
- King, B.J. Fat Wars: 45 days to Transform Your Body. Toronto: Macmillan, 2002.
- Patterson, C.R. Essentials of Biochemistry. London: Pittman, 1983.
- Taskinen, M.R., and E. Nikkila. “Lipoprotein Lipase of Adipose Tissue and Skeletal Muscle in Human Obesity” Metabolism 30 (1981): 810–17.