Understanding Carbohydrates
What is a carbohydrate? (this is the boring science part, feel free to skip ahead)
A carbohydrate is a molecule made up entirely of carbon, hydrogen and oxygen atoms. Some carbohydrate molecules are small, containing only 3-7 carbon atoms. These are called monosaccharides. If 2 monosaccharides link up, the new molecule is called a disaccharide. Mono- and disaccharides are found in fruit, root vegetables, milk, sugar, honey and maple syrup. When humans eat these foods they can use the mono- and disaccharides for immediate energy. If energy is not needed at that time, the carbohydrates are typically converted to fat and stored for (potential) future usage.
If more than 2 monosaccharides link up they form a polysaccharide. Plants such as fruits, vegetables, grains, legumes, nuts and seeds store polysaccharides for their own energy needs. When humans eat plants they can break the polysaccharides down into monosaccharides and use them for energy or fat creation. There is, however, one type of polysaccharide that we cannot break down and that is fiber. Fiber remains intact throughout our stomach and intestines and ultimately serves to feed the bacteria that live there as well as provide bulk for our stool.
Do carbohydrates cause weight gain?
The short answer: yes, they definitely can. But not necessarily. It ultimately comes down to your body’s ability to convert carbohydrates into energy, as well as how well your carbohydrate intake matches your body’s energy needs. The doctrine in America for the past 30 years has been that only the latter matters. Energy in, energy out. Eat more food than your body needs and you will store the excess as fat. While that premise is not untrue, it is also not that simple. Yes, hyper-palatable, sugary, fatty, salty foods like fast food, pop, candy and chips have made it easy for people to consume more calories than their body needs. That absolutely plays a role in America’s obesity crisis. But it’s not the whole story.
A lifetime of these nutrient-devoid, hyper-palatable foods does something much worse to the body than just provide extra calories. It causes the onset of a condition called insulin resistance. Insulin is a hormone that allows glucose (a monosaccharide also known as sugar) to enter the cells in our body for use in energy creation. Imagine insulin as your hand unscrewing the gas cap on your car, allowing you to fill up the tank. Now imagine that the gas cap is stuck. Like really, really stuck. There’s nothing wrong with your hand (insulin), but no matter how hard you try, you can’t get the gas cap off. That’s what happens when someone becomes insulin resistant. The body’s first response is to get help. The pancreas tries to help by sending out extra insulin molecules to try to get the cells to open up. This works, but it also causes some problems. High levels of insulin are a sign that your liver should start converting glucose to fat for storage. Hence why weight gain typically occurs before blood sugar levels go up. In a way, weight gain is the body’s desperate attempt to PREVENT diabetes. This is much different than the common narrative that obesity CAUSES diabetes.
The American Medical Association has gone so far as to classify obesity as a “disease,” but I disagree with this entirely. The definition of disease is “a condition of the living animal or plant body or of one of its parts that impairs normal functioning and is typically manifested by distinguishing signs and symptoms.” The disease is insulin resistance. Once a person’s cells become insulin resistant, their ability to use carbohydrate for energy becomes impaired. This is first seen outwardly by weight gain. Thus weight gain is the SIGN/SYMPTOM, insulin resistance is the DISEASE. In my practice I always seek to address the underlying disease, not just the signs and symptoms. And in the case of insulin resistance, that means talking about carbohydrates.
I’m young(ish) and healthy(ish), so I’m probably fine, right?
Well…maybe. Maybe not. We know that approximately 10% of Americans have diabetes and 33% of Americans have pre-diabetes. So that’s almost half of the population that already has elevated blood sugar and is absolutely not fine. But remember, the body can be insulin resistant for DECADES before blood sugar starts to climb. It spends those decades pumping out more and more insulin to help jam glucose into cells. You may notice a slow but steady weight gain during this time, likely just chalking it up to aging. Some people don’t see much weight gain but they notice other signs like chronic fatigue as their body struggles to use carbohydrates for fuel. Again, it’s usually ignored – who isn’t tired in their 30’s and 40’s, right?
It’s time to wake up and smell the [sweetened] coffee folks!
The goal should not be to wait until blood sugar rises to start altering the diet. By balancing your diet NOW, you may be able to tolerate carbohydrates for your whole life. But once you go too far down the insulin resistant path the only true solution is to cut carbs from your diet. A profoundly insulin resistant person is, for all intents and purposes, carbohydrate intolerant. To continue to eat a high carbohydrate diet at that point is illogical and dangerous. Of course we have countless diabetes medications we can throw at them, but diet should always come first. Telling an insulin resistant person to continue eating carbs and just take diabetes medication is akin to telling a person with a peanut allergy to keep on eating peanuts, just inject their EpiPen every time they do.
So what should you do?
My advice varies, as it should, based on your personal insulin sensitivity.
Kids
Generally speaking we can assume that most pre-pubescent kids are still pretty insulin sensitive, though sadly this is not always the case. If a child is overweight, it is possible that they have already lost some insulin sensitivity. But for most kids the focus should be on maintaining their insulin sensitivity by avoiding foods that over-tax the metabolism such as sugar and refined flour. It is so easy to say that they’re kids, they’re active, they’re skinny, it doesn’t matter what they eat. But it DOES matter because the effects of these foods are cumulative. Sure, feed them lots of whole food carbohydrates like fruit (not juice!), potatoes (not chips and fries!), oats (not pre-sweetened and flavored!), corn (not in the form of Fritos!), brown rice (not white!), and 100% whole wheat foods like bread, crackers and pasta. These foods are nutrient dense and provide great fuel. But white flour, white rice and deep fried potatoes should be avoided at home (they are nearly impossibly to avoid at restaurants), sweets should be limited to special treats, and for heaven’s sake, please, please, please do NOT serve kids sweet beverages of any kind (including juice, smoothies, sports drinks and chocolate milk!).
Healthy(ish) Adults
If you are an adult that was raised in a typical American family (or any country with a similar food supply), there is a good chance that you are slightly insulin resistant. I think it is prudent for most adults in today’s world to be judicious about their carbohydrate choices. That’s not to say you should jump on the keto bandwagon, but rather that you can take the same guidelines that apply to kids (whole food sources of carbohydrate) and be a little more careful about portion size. And again, for the cheap seats, STOP DRINKING SWEETENED BEVERAGES!!!
Anyone Diagnosed with Pre-Diabetes, Type 2 Diabetes or Gestational Diabetes
If your blood sugar is already starting to go up, we can say with near certainty that you are insulin resistant. At this point the best thing you can do is reduce your overall carbohydrate intake. Working with a dietitian (such as myself!) can help you to figure out your personal “carbohydrate tolerance.” In other words, the amount of carbohydrate that drives your blood sugar into a dangerous range. A simple glucose meter combined with a food log is the easiest and cheapest way to do this. Talk to your doctor about getting a prescription if you haven’t already. Also, just in case you missed it, please stop drinking sweet beverages. Pretty please?