Even many experts consider the debate over good carbs and bad carbs the most confusing aspect of dietary advice. What is a carb? What are good carbs? And why does it matter?
Many people, maybe you, have come to base their diets on eating far fewer carbohydrates. Even further, some separate the carbohydrates they do consume into “good” and “bad.”
To make choices even harder still, there’s the glycemic index (GI), a sort of measurement applied to carbs based on how much and how fast they spike blood sugar and insulin.
What is a carb?
Before you begin to consider the good and the bad, it helps to understand what purpose carbohydrates serve in the human body. Simply put, they provide the energy we need to conduct our everyday lives. You need carbs in your diet. Otherwise, your cells are running on a drained battery.
Your brain, nervous system, and muscles need carbs for nourishment. In your body the predominant carb is glucose. In your blood, glucose is labeled “blood sugar,” a main energy source.
The simplest carbs are sugars such as glucose, fructose, lactose, and sucrose. More complex carbohydrates, such as starches, are made up of strings of sugar molecules bound together.
The debate over good versus bad is essentially one of complex carbs (good?) and simple carbs (bad?). The decision is usually based on how quickly your body processes the carb you’ve just eaten and how much (and quickly) it raises your blood sugar level.
That spike is considered in the context of higher risk for diabetes, heart disease, cancer, and your ability to lose weight. Your weight, in turn, can increase your risk for those diseases.
The effect of the glycemic index
But, according to one study, it’s not as simple as sugar. The researchers found that foods with similar carbohydrate content can “differ in the amount they raise blood glucose.”
“The effects of this property, called the glycemic index, on risk factors for cardiovascular disease and diabetes are not well understood,” the authors wrote.
One report on the GI says using it to decide whether certain foods or combinations of foods can be “misleading,” but it could help you “fine-tune” your diet if you have diabetes.
If you are diabetic, conventional wisdom is that you should carefully monitor the total amount of carbohydrates in what you eat. Second, for “fine-tuning,” you can use before-meal and after-meal glucose testing to customize your own glycemic index.
Plus, when you lower your total amount of carb consumption, you lower cardiovascular risk factors like cholesterol, triglycerides, and blood pressure.
Typical recommendations are that you eat more whole grains, beans, fruits, and vegetables, while cutting back on highly processed and sugary foods and drinks. If you follow that advice, you’ll almost “automatically” lower your glycemic load anyway.
So, in effect, you’re now being told there are indeed good and bad carbs, or those you should consume and those you shouldn’t, but not according to where they fall on the GI.
Confused? You’re not alone. Fad diets and the GI tend to make what you should eat harder to figure out,
Because of the popularity of low-carb diets, which many people automatically adopt without knowing why, some carbs that have been labeled bad are actually good for you. Those include corn, bananas, breakfast cereal, white potatoes, sourdough bread, and green peas.
Good food for diabetes
To wade through all the information out there without feeling like you’re sinking in dietary quicksand, look at “good” carbs as those that have a high natural content of vitamins, minerals, and phytonutrients (typically non-processed foods). They also are high in fiber, boost metabolism, and are filling so your brain’s control center for satiety keeps you from eating more.
Sometimes you eat just to eat, and for Americans that often means readily available and cheap junk foods with little nutrient value. The level of “empty’ carbs or fats in them though, can cause you to gain weight.
There is no debate about obesity. It increases your risk for many diseases.
When it comes down to it, just eat a healthy diet. That naturally increases what could be called “good” carbs and naturally reduces or eliminates what could be called “bad” carbs. Keep it simple, but always be aware of what you’re eating and what’s in it.
February 28, 2020
Christopher Nystuen, MD, MBA