The terms “starch,” “carbs” and “sugars” seem to get conflated quite frequently into one concept in today’s cacophony of nutritional advice. But this is an oversimplification. Remember your geometry lessons: All squares are rectangles, but not all rectangles are squares. Something similar happens here: All complex carbohydrates (starches) are composed of simple carbohydrates (sugars), but not all sugars combine to form starches. In fact, during the industrial processing of foods, often all that remains of a whole plant is its simple sugar. Let’s chat a little bit about understanding the differences in all these inappropriately consolidated terms.


Plants contain a very strong fiber called cellulose. It is what gives plants their shape, and is what allows them to maintain a barrier between the outside world and their internal cells. It isn’t digestible by humans, it’s that tough. Even grazing mammals require bacteria in their guts to break down the cellulose for them. In nutrition we call cellulose by the name fiber. There are different kinds, but that isn’t the focus right now. What matters is that whole plant foods contain it, and many processed foods do not (or have the natural fiber stripped out, just to have some other source of fiber supplemented back in).

The reason fiber is important to this discussion is because it slows down digestion (it provides many other important benefits as well). Your body has to work harder to more gradually extract the energy and nutrition from whole plant foods. That sheath of cellulose is what causes the body to release less insulin and to do it over a longer period of time, which is what maintains energy levels. This in turn also makes you feel satiated, which encourages you to eat less. There really aren’t any downsides to eating whole foods. And if you are gluten intolerant or gluten sensitive, there are plenty of plant foods that don’t contain it. Quinoa, so long as you aren’t allergic to it, is a fantastic gluten-free source of fiber, starch and complete protein.

Complex Carbohydrates/Starches

I just used the term starch. Starches are comprised of three or more simple sugars that have been joined together at the molecular level to create long chains and coils. When they are accompanied by fiber, they require much more time to be metabolized. These are called “good carbs,” because they have a lower glycemic index, and therefore won’t cause you to have insulin spikes and energy crashes. They also tend to be rich in vitamins and minerals, because the nutrients haven’t been stripped out by chemicals and heat in a factory somewhere. So then, starchy carbs aren’t bad for you unto themselves.

Complex carbs/starches should comprise the largest portion of your calories, because this is the body’s most efficient source of energy. It also supports muscle repair. Vegetables, tubers, nuts, seeds, quinoa and whole grains are all sources of complex carbohydrates.

What you do not need much of is simple carbohydrates.

Simple Carbohydrates/Sugars

Simple carbohydrates are one or two sugars on their own, often served to us without any fiber accompanying them. Thus they dissolve very quickly, are generally devoid of vitamins and minerals and hit your blood stream almost immediately. Without cellulose/fiber encasing them, there is no barrier between them and your intestinal acids and enzymes. This sudden onset of a huge amount of energy elicits a panic response in your body, a much larger amount of insulin is released to absorb all the sugar, most of it gets stored as fat, and then you have an energy crash. You will also become hungry again, because simple sugars have no real mass to them. A great example of making a nutritious whole food into a dangerous sugar is orange juice.

Whole fruit vs. drinking juice

When you eat an entire orange, you get its succulent juice along with all the fleshy cellulose. Although fruit is nature’s candy and should be limited in your diet, a whole fruit will practically always be better than its juice alone.

Consider this: Even if you hand press an orange thoroughly, your glass will have hardly any juice in it. You will therefore need to squeeze anywhere from 6-12 oranges to fill the glass. Think about that: You have just vastly increased your number of calories in the form of sugar, and you haven’t gotten any of the fiber from those oranges.

You will not get full. You will have to eat other foods along with the juice to make a meal (increasing your calories even more) and you will have an insulin spike to contend with all the food. The same is true of other juices, the skins and flesh contain fiber and minerals in addition to the nutrition of the juice. Eat your potatoes with their skins! Avoid fruit juices, limit whole fruits (especially dried fruits) and focus on vegetables and other sources of complex carbohydrates that are accompanied with fiber.

info: Jack Kirven completed the MFA in Dance at UCLA, and earned certification as a personal trainer through NASM. His wellness philosophy is founded upon integrated lifestyles as opposed to isolated workouts. Visit him at and