Nutrition jargon can get incredibly confusing if you don’t have a lot of time to spend on background research – and the hotter a topic is, the more jargon it typically has. To help you figure it all out, here’s a quick look at some of the carb-related terms you’ll see thrown around: what they mean, where they come from, and whether or not you even need to worry about them at all.
Simple vs. Complex Carbs
“Complex carbs” are the Food Pyramid’s answer to everything. Diabetes? Complex carbs! Heart disease? Complex carbs! Complex carbs! Weight loss? Complex carbs! But are they really all they’ve cracked up to be?
Here’s the background: all carbohydrates break down into simple sugar molecules. Fructose and glucose are two examples of simple sugar molecules. Simple carbs, also called sugars, are made of one or two simple sugar molecules stuck together. An example of a simple carb is table sugar. Complex carbohydrates are made of three or more stuck together. An example of a complex carb is dietary fiber.
That’s the scientific definition. Most whole foods contain both types of carbohydrates, in varying ratios. But in everyday language, people refer to foods as though any given food was either “simple” or “complex” with no in between. And they simplify these technical terms to the point where they lose all meaning – “simple” just becomes a way to say “bad,” and “complex” becomes a way to say “good.”
Some nutritionists refer to anything with nutrients attached as “complex carbohydrates” and anything without nutrients attached as “simple carbohydrates.”
Others call it a “simple carb” if the food contains no fiber, and a “complex carb” if it does – even though fiber is just one type of complex carbohydrate.
Others claim that simple carbs are the carbs that raise your blood sugar, but this is silly: fructose is as simple as carbs can get, and it raises blood sugar a lot less than many complex carbs.
Others simply equate “complex carbohydrate” with “whole grains” without any rationale at all.
Basically, the simple vs. complex distinction has become a way of advertising whatever kind of carbs someone thinks are healthier than others, with no scientific rhyme or reason behind it. And since it’s all based in conventional wisdom, it’s not useful at all from a Paleo standpoint. For one thing, it doesn’t tell you anything about whether the food contains any antinutrients or gut irritants at all. Just ignore it; it’s not worth your worry.
Glycemic Index vs. Glycemic Load
Time to move on to a closely related topic, the glycemic index/glycemic load confusion. Here’s the difference:
Glycemic index (GI): a measure of how much the carbohydrates in a given food spike your blood sugar compared to the same amount of carbohydrates from other foods.
Glycemic load (GL): a measure of how much a typical serving of a given food spikes your blood sugar compared to a typical serving (which may or may not be the same amount) of other foods.
For example, to compare the glycemic index of honey and broccoli, you’d take 50 grams of carbohydrates from each and compare them. To compare the glycemic load of the two foods, you’d take a serving of broccoli (about a cup) and a serving of honey (about a tablespoon) and compare them.
The maximum GI is 100 (that’s pure glucose). Most fruits and vegetables have a very low GI; bananas and most dried fruits have a medium GI, and white bread, processed grains, and similar foods have a high GI. GL measurements use a similar scale; they’re basically just weighted GI measurements. Most foods with a low GI also have a low GL (although there are a few exceptions).
On the face of it, this sounds like a very useful measurement. Who wouldn’t want to pick the carbohydrates that cause the smallest spikes in blood sugar? That’s just logical. But it has some big problems:
The glycemic index/load measurements test the food in isolation, even though the actual effect on blood sugar depends on what you eat the food with. People rarely eat just a random tablespoon of honey by itself; they usually eat it baked into a recipe, or drizzled on ice cream. It’s the GI/GL of the meal that counts, but you can’t tell that just from looking at one ingredient.
Fructose, which has a very low GI of around 19, is bad for you in other ways. So don’t take a low GI as a measure of overall healthiness.
Also, like the simple/complex distinction, the glycemic index tells you nothing about whether a food comes packaged with things you don’t want to eat. For example, most beans have a very low GI, but that doesn’t make them healthy.
The upshot: knowing the Glycemic Index or Glycemic Load of a starchy food is interesting, but it tells you just one thing about its potential health qualities. It doesn’t touch on many other important aspects of the food, like fructose content. And if you’re eating the starchy food in the context of a complete meal, the glycemic index is almost irrelevant. So basing an entire diet off of just this one measurement (yes, there actually is a Glycemic Index Diet!) is silly.
How do Paleo Carbs Stack Up?
By now you know that both the simple/complex distinction and the GI/GL number have some serious limitations. But just for your information, here’s how the “safe starches” of the Paleo world stack up (data from here):
Simple or complex? (Biologically)
Glycemic Index (1-100 scale)
Glycemic Load (1-60 scale)
High (but lower than white potatoes)
There aren’t any precise numbers in this chart because the exact score depends on how you cook the food (e.g. boiled vs. baked potatoes).
Remember: this is not a chart telling you how “healthy” these foods are. Sweet potatoes have a slightly lower GI than white because they have more fructose. If you’re sensitive to fructose, that might be worse than the higher GI. And pumpkin has a remarkably low GL because it’s just not very calorie-dense: in a typical serving of winter squash, you’re not getting many carbs. If you need some carb calories, that might not be an advantage.
What Does it All Mean?
Unfortunately, the big takeaway here is that there are no easy answers. Life would be so simple if we could just look at one number and decide whether a food is good or bad for us! But that’s not the way it works, and oversimplifying a complicated problem won’t do you any good.
So if considering the glycemic index as one piece of information among many helps you make food choices that work for you, go for it! We have the tool; we might as well use it. But the distinction between simple and complex carbs is not very helpful to most people, and there are so many health considerations that aren’t covered just by these simplistic numbers. Use them for what they’re worth, but don’t overestimate them.
Hungry for More?
Did you notice that Paleo Diet Lifestyle now has a brand-new identity as Paleo Leap? And as a user-friendly welcome mat for our new home, we’ve published a carb directory, where you can get answers for any more carb-related questions you might have. You can read all about the name change to Paleo Leap here - and make sure to check out our beautiful new site while you're at it! Or get in touch on Facebook and Google+; we’d love to hear from you!