What does eating carbs do to your body?

Carbs have been vilified for decades, but the rise in popularity of the feared Atkins diet in the early 2000s made “You eat carbs!” the insult of choice among shallow teenagers everywhere. But when something is made bad, people start to misunderstand it. For example, many people now think that carbs are things like bread, cake, and rice. So, what are carbs and how do they affect your body?

In the TED-Ed episode linked above, the first lesson is that you can avoid white bread all you want, but if you drink soda or eat salads, you’ve been in Carb Town the whole time. In fact, a whole loaf of bread, a bowl of rice, and a can of soda all have about the same amount of carbohydrates, and important fruits and vegetables like tomatoes, avocados, and carrots are all high in them. Does that mean you need to cut out a lot more than you thought from your diet to stay at a healthy weight?

First, let’s make sure everyone knows what we mean when we say “carbs.” Carbohydrates are a type of nutrient that includes sugars and the molecules that your body breaks down to make sugars. Depending on how they are built, they can be simple or complex. As the video explains, when we talk about simple sugars, or monosaccharides, we mean glucose, fructose, and galactose. Glucose is found in all foods with carbohydrates, and fructose and galactose are found in fruits and milk, respectively. Two of these sugars can be combined to make more complex disaccharides, such as lactose, maltose, and sucrose.

Complex carbohydrates, on the other hand, are made up of three to ten linked sugars that our small intestines can break down into energy.

So why does eating a doughnut not have the same effect as eating broccoli? Both are high in complex carbohydrates, which means they give us a good boost of energy. So why can’t I just empty my fridge and live off a crate of pastries for the rest of my life? Even though both starch (found in doughnuts) and fiber (found in broccoli) are high in complex carbohydrates, the way the simple sugars are linked affects how your body uses them.

Basically, your body can easily break apart the links in starch to get to all that sweet, sweet energy. This is the biological reason why you crave sugar so much around 3 p.m. Foods with a lot of fiber, like apples, whole grains, and vegetables, are much harder to break down and release energy more slowly. The Glycemic Index (GI) is the rate at which your body breaks down complex carbohydrates into simple sugars like glucose, which raises your blood-sugar levels. Meat, cheese, and eggs have the lowest GI, according to TED-Ed.

Even foods that start out with a high GI can be made healthier by the way they are prepared, as a 2015 study on rice showed. It turns out that if you cook rice in a certain way, you can cut its calories by half. This is because of what happens to those sugar bonds when you heat and cool them.

So, do carbohydrates make you fat? Yes, and they can lead to health problems like high blood pressure, heart disease, and type 2 diabetes. I’ll let the video above tell you how to avoid that, but let’s just say it has something to do with how you decide to eat that pasta-sushi-burrito-doughnut-burger, which is available for a limited time only at the Worst Restaurant Ever.