Conquering Carbohydrates Part 3: The Complex Carbohydrate Conundrum


A few weeks ago, we posted Carbohydrates For Dummy’s Part 1: Saccharides and Such. 

A week after that we posted Part 2 of the Conquering Carbohydrates story: an introduction to Complex Carbohydrates.

Then came a few distractions and the Annual Fair Foods Blog, but we’re back on track today  with the 3rd and final part of the Conquering Carbohydrates Conundrum.

Glycemic Index and Glycemic Load

If sugar, starch, simple carbs, complex carbs, and ne t carbs weren’t enough to test your meddle, two other sometimes confusing carb-centric terms to contend with are Glycemic Index (GI) and Glycemic Load (GL).

Glycemic Index simply ranks foods on how quickly they affect glucose levels in the blood stream.  Developed in Toronto in the 1980s to help doctors prescribe diets for diabetics, foods that quickly elevate blood sugar levels have a high glycemic index.  Foods that increase blood sugar slowly have lower glycemic indices.

In addition to Diabetics, Athletes also tend to be highly aware of blood glucose levels to both prepare for and recovery from intense exercise.   Regular exercisers can also benefit from an awareness of blood sugar levels, however, because the of the effect cortisol has on glucose metabolism when you are low on blood sugar.

You might think that you’re doing yourself a favor skipping lunch, when in fact, doing so triggers your body to generate more cortisol.

Cortisol … the “your under stress hormone” counteracts Insulin production and reduces the metabolism of glucose.  The result of this is disproportionately more fat storage in anticipation of famine!  Additionally, the increased Cortisol increases appetite so you’re more likely to overeat at your next meal!

It would be great if you could simply categorize carbohydrates into glycemic index groups that fit nicely within some saccharide category, but the truth is, it’s somewhat of a frustrating memorization exercise.

Take roots.  Carrots & yams (both simple carbohydrate foods) have relatively low GIs of 39 and 51, respectively, while potatoes have GIs as high as 85!   The difference here is that potatoes are very starchy.

So, starchy means high GI then?

Not quite. Plenty of other starchy carbs, like Oats, Bran, Rye and Barley are actually quite low in GIs scoring in the 20s and 30s.  Similarly,  wheat and most rices also score fairly low (50s), while brown rice pasta has an exceptional and soaring 91!

And then there’s fruit.  Unless I’ve missed something, no fruits are starchy.   They’re fibrous and watery, but not starchy.  But here’s the rub: some fruits have very low GIs, like grapefruit (25), plums (39), and apples (38); and some fruits have moderate GIs, like mangos (56), apricots (57), and raisins (64).  Why then, does watermelon have a sky high GI of 72?

It makes no sense, and in the end, you must simply memorize or carry GI tables with you to get it right!   Here’s one build for the sometimes-popular South Beach Diet.

Attempting to solve this mystery steps in Glycemic Load.

As it turns out, part of the reason why inconsistencies exist across the simple to complex carbs GI spectrum is related to quantity consumed.   For example, a single piece of hard candy (nearly all sucrose) will trigger a smaller glucose response than a bite of a banana.  But if you consume 2 cups of each, the candy outpaces the banana quite quickly!

What’s more, Net Carbs also have a role.  As mentioned above, the fiber content will affect digestion speed, which, in turn, effects blood sugar fluctuations.  So, in the late ‘90s,  the Glycemic Load became a more popular way to determine food effect on blood sugar, defined as the percentage of GI times Net Carbs:

Glycemic Load = Glycemic Index / 100 x Net Carbs

Got that?  Well, before you start looking for a smart phone app to calculate GL, have no worries, many nutritionists have simply done the math for you with tables they’ve built themselves.  In fact, one of my all time favorite nutrition sites, NutritionData.com doesn’t list GI at all, but instead lists an Estimated Glycemic Load number for most of it’s nutritional listings.  The values are estimated simply because complete data on GI and Net Carb values simply hasn’t yet been compiled for all foods.

What you also need to know about GI vs GL numbers is that a high GL number could be a low GI Number:

Within the heavily debated carbohydrate controversy, exists a separate embedded micro controversy around GI and GL.  As with carbohydrates, many experts propose low GI/GL diets within the weight reduction context, while others staunchly oppose it.  A 2008 German study, for instance, actually found that low GI/L diets actually correlated to higher bodyfat results.

Withstanding GL wizardry, one food category that emerges consistently high in the GI tables is highly refined grains, particularly those in baked goods.  French bread, cookies, cakes, doughnuts, rice cakes, and many breakfast cereals ALL SCORE very high on GI tables.

Refined Grains and Added Sugars

Refined grain products (cookies, cakes, cereals) also suffer from two other significant problems: added sugars and nutrient deficiency.

In fact, according to the  USDA’s 2010 Dietary Guidelines for Americans, the single largest problem with many American diets is, indeed,  these refined grain products.

Not only do they trigger a short, spiky bust in glucose, but they are also reasonably ‘empty’ calories with very few micronutrients (vitamins and minerals).  To make matters worse, they frequently include added sugars to make an already unhealthy food even more caloric.  Sometimes inclusive of saturated and/or hydrogenated fats as well, and well, these products are really quite evil to health and fitness professionals.

The Carbohydrate Conundrum: What to do?

With all of this going on, it’s no wonder the general public is confused about carbohydrates and their dietary relevance.  Here then is my professional recommendation on the topic.

First, if you are diabetic, follow your doctor’s orders, not mine.

For all the rest of us:

  1. The easiest way to defuse most of your concerns about carbohydrates is simply to exercise more!  Not only will you metabolize more calories in doing so, but other hormones involved with exercise and exercise recovery help keep cortisol and insulin balanced.
  2. Recognize that carbohydrates are, above all else, your body’s primary fuel source.   While it’s true that your body always metabolizes a blend of carbohydrates, fats, and protein, carbohydrates are your primary fuel source.  If your engine is just idling, back off on the fuel!
  3. Adjust your complex carbohydrate intake with your anticipated physical activity
    1. If you are sedentary, you need very complex few carbohydrates.  Most of your energy will come from stored energy sources (glycogen and body fat).   Eliminate most complex carbohydrates from your diet to avoid gaining body fat.
    2. If you are active, you need some complex carbohydrates.  Try to get most of your complex carbohydrates early in the day, typically before 2:00 PM.  Switch to mostly simple carbohydrates after that.
    3. If you are regularly exercising, or an athlete, you need a LOT more carbohydrates. Get most of your complex carbs early in the day, but do include moderate quantities later in the day.  Don’t hesitate to include higher amounts in your diet if you have a high intensity exercise event the following morning.
  4. Eat a wide variety of and large quantities of fruits and vegetables.  Follow the seasonally available produce and you’ll get plenty of variety.  Make sure you get at wide variety of color in your diet.   A lot of people miss out on the yellows: squash, yams, yellow peppers.
  5. Try to incorporate more legumes into your diet: green beans, black beans, pinto beans, white beans; etc.
  6. When choosing complex carbohydrates, focus on whole grains, and high fiber sources.  Steel cut oats, whole wheat, and wild rice are good examples.
  7. Always avoid or minimize highly refined grains, particularly those with added sugars.  MOST of the grocery store bakery fits into this category: cookies, cakes, pies (it’s the crust), french bread, muffins, and doughnuts.   What’s worse is that many of these will also include partially hydrogenated fats.
    1. Avoid or eliminate them if you are serious about your health.
    2. Heart disease is still the #1 cause of death for men and women in America and these fats are deadly
Did I Miss Anything?   What’s your burning or unanswered carbohydrate question? 

Carbohydrate Quiz


Conquering Complex Carbohydrates – Part 2 of Carbohydrates for Dummy’s


 Part 2 of a 3 part series on conquering carbohydrates, today, we focus on Complex Carbohydrates: where they’ve fit into diets and dietary conversations.

Last week, we covered Carbohydrate conversational history, and Simple Carbohydrates: Saccharides / Sugar.

Disaccharides

Chaining two saccharides together creates a slightly more complex type of carbohydrate called a DIsaccharide.   Three of the most common disaccharides are Sucrose, Maltose, and Lactose, all formed with a different combination of monosaccharides:

Disaccharide

Monosaccharide + Monosaccharide

Sucrose =

Glucose + Fructose

Maltose =

Glucose + Glucose

Lactose =

Glucose + Galactose

Sucrose naturally occurs in fruits and vegetables and is highly concentrated in cane sugar and sugar beets.    

It is also common table sugar.

NOTE: Some canned fruit and vegetable products will also ADD refined sugar (like high fructose corn syrup and common table sugar) to the processed food, to sweeten the flavor.  You need to be careful of the extra sugar and extra calories.

I also learned this week, courtesy of Breakfast Club Guest Speaker Steve Zeller of Waconia’s Parley Lake Winery that Winemakers sometimes add sucrose to highly acidic wines to improve palitability. 

Polysaccarides

Stringing 3 saccharides together creates, you guessed it, a trisaccharide, while 4 or more saccharides builds a polysaccharide.

And this is where things get really interesting … and controversial. 

Three of the most common polysaccharide carbohydrates are Starch, Glycogen, and Cellulose.

Starch is insoluble in water and must be digested by animals.  It is a glucose reserve for plants (excess plant glucose is converted to starch).  Rice, wheat, and corn are common sources of starch in the human diet.

Glycogen is a reserved form of glucose for animals (not too unlike how starch is a glucose reserve for plants).   It is manufactured by the liver and is stored in the liver and muscle tissues.  It must be converted back to glucose to be used as an energy source.

Cellulose is produced by and forms the primary structure of plants. While technically a polysaccharide carbohydrate like Starch and Glycogen, the cellulose molecular structure makes it indigestible by mammals.  It is therefore considered fiber, and not really an energy source.

Complex vs. Simple Carbs

If you’re observing the carbohydrate reduction battles, these complex carbohydrates are exactly the carbs that tend to be under the most scrutiny.

The easiest way to separate Simple Carbohydrates from Complex carbohydrates is to identify Starch.  Complex Carbohydrates will almost universally contain Starch.

Fruits and Vegetables do not; they consist primarily of water, cellulose (fiber), and fructose.

Complex carbohydrates are then primarily carbohydrates with a starch element.  These include most of the grains (wheat, oats, barley, rice, and corn), some roots (potatoes, yams, turnips), and some legumes (beans).   Most also have significant cellulose content making them high in fiber.

Low and No Carb Diets

While extremely low carb diets like Atkins eliminates nearly all carbohydrates, mono and disaccarides included, some diets, like South Beach allow for most monosaccarhide and disaccaride carbs, but banish the more complex ploysaccarides.

The big difference in these two approaches is that the carbohydrate threshold below which an Atkins style diet places your body in what’s called a state of ketosis whereby glycogen stores are depleted, requiring that energy comes entirely from the metabolism of fatty acids.

Most of the medical community considers this a highly risky and potentially life-threatening taxation on the liver.

Ketosis risks notwithstanding, another at least as significant problem with many low/no carb diets is micronutrient deprivation.  Despite the phenomenal products from many supplement providers, matching natural food vitamin and mineral content is extremely difficult.  Missing out on all of these in the absense of a saccharide smart diet is simply not a healthy, long term way to provide nutrients to your body.

Net Cabohydrates

Net Carbohydrates are an interesting new term in the diet world whereby the diet du jour architects and food manufacturers have decided that the carbohydrate content defined by the USDA isn’t meaningful for the fibrous component in a food product.

So, what they’ve done is created a new value: Net Carbs, defined as the total carbs in a product less the fibrous content.

In no small way, this is merely a ruse to position products in a more favorable light to carb conscious dieter.  

While the Net Carb idea is somewhat honorably used to identify the energy sources relevant to body fat storage (or elimination), disregarding the fibrous (often cellulose) component in this way sidesteps several other metabolic and digestive considerations.

For one, high fiber carbohydrate products digest more slowly, and in some cases much more slowly than a low fiber food.  This results in a slower, and more steadily produced stream of glucose in the blood stream … something highly significant to 25+ million Americans with diabetes.

Second, high fiber diets are healthy!  They reduce the risk of developing certain cancers and heart disease, have a positive effect on cholesterol levels, and help with weight control programs by providing ‘filler’ the body often identifies as food to reduce appetite. 

As a result, the Net Carbs numbers tend to do more clouding than clarifying.

In the end, your time would probably be better spent simply looking at and monitoring the sugar and fat content of a food than bothering with the net carb calculation.

In fact, as an isolated factor, you might actually choose a less healthy product on it’s net carb merits!

For instance, a serving size of McCann’s Steel Cut Irish Oatmeal has 27 grams of carbohydrate.  Of that, 3 g are dietary fiber, while 2 g are Insoluble fiber.  Hence, the net grams of the product are:
27 – 3 – 2 = 22g.

On the flip side, a serving of General Mill’s Cocoa Puff’s has 23 total grams of carbohydrate.  Of that, 1 g. is dietary fiber for total net carbs of 22g as well.

Equivalent products then?  Not even close.  The oatmeal has than 1 g. of sugar while the Cocoa Puffs have a whopping 13 g of sugar!  Further, the serving of oatmeal includes 4 g of protein while the serving of cocoa puffs has just a meager 1 g of protein.

What’s more, the 5 g of dietary fiber in the oatmeal will give it a much lower glycemic index (tune in next week) than that low fiber General Mill’s product, something that will effect hormones in a far more influential way.

Though … from a net carb perspective … the products look equal.   

Unfortunately, a desperate public blindly following the net carb lemmings may make poor, and uninformed decisions.  Don’t let that be you!

Next Week: Glycemic Index and Glycemic Load; Refined Grains; what to do? 

Like last week, leave me a comment and we’ll spot you a free water bottle!