What happens to Carbs after we eat them?
I was thinking about what topic to write about this month and I figured in continuation with our digestion discussion last month, I will discuss how our body actually digests carbs and how that can be related to unwanted weight or even health problems down the road.
Remember digestion occurs in the mouth, stomach, small intestine and large intestine. So, lets dive into what happens in each, that’s specific for carbohydrates:
Mouth: The enzymes in your mouth actually begin to break down carbs into smaller pieces. However, because food only spends a few seconds in your mouth, this is short lived. This is why the longer your chew (especially with starchy, or bready foods), the better. Gives your digestion a head start. Then it travels into your
Stomach: The acid in your stomach actually shuts off these enzymes from your mouth, preventing them from working further. This means, that carbs are not digested at all in your stomach (boring!). They just wait there until they enter your
Small Intestine: Enzymes (lots of them!) are released here to really break down all the carbs you have just eaten. How fast this occurs depends on the type of carbs you just ate. I think most people have heard of simple vs complex carbohydrates. But what does this actually mean? Actually, it goes back to molecular chemistry (yay chemistry!) So get ready for some science talk real quick:
Technically all carbs you eat contain a small sugar molecule called glucose. It doesn’t matter if its a candy bar, an apple or a piece of bread. They all contain glucose. What differs between them is the amount of glucose and how glucose is arranged.
It can be just 1 or 2 glucose molecules together, or glucose can be with another sugar, like fructose. These tiny sugar molecules are what are classified as Simple sugars. Because they are only a few of them with only 1 or 2 bonded together, they are “simple.”
Table sugar (sucrose) for example, is 1 glucose molecule attached to 1 fructose molecule. Or lactose (like in milk products) are 1 glucose molecule and 1 galactose molecule (another type of sugar) bonded together. Since, these are small molecules, it doesn’t take any effort to digest them. Your body absorbs these little guys very fast, since they are already small.
What has simple sugars in them? Anything with table sugar (sucrose), high fructose corn syrup, maple syrup, honey, agave…..basically anything we would classify as “sugar.” It doesn’t take a lot of effort to digest these things because they are already small. So, the sugar gets absorbed into your blood stream very fast (high blood sugar).
Now imagine you have 1000’s of glucose molecules attached to one another. That’s a lot of glucose! These are your complex carbs. Much bigger molecules, compared to the simple ones that only have like 1 or 2 sugars, hence why they are “complex.”
These complex carbs are found in your starchy foods (like wheat flours, bread products, potatoes, rice, etc). The enzymes can still break these down into tiny sugars because they are still technically sugar, just more of it. However, it will take longer to break down, because the molecules are bigger, but it still will happen. Once, they are broken down small enough, all these tiny sugars are also absorbed into your blood (high blood sugar).
This is why if you were ever to measure your blood sugar after eating a candy bar vs. pasta, your blood sugar will be high. It doesn’t matter the source of the sugar, its all sugar and your body treats it the same way.
But if it doesn’t get broken down in the small intestine, the carbs end up going into the
Large Intestine: If you have eaten too much carby foods that your small intestine can’t break down, it is all is up the bacteria in your large intestine to handle. This is why people complain about bloating when they eat too much bread or pasta. That’s the bacteria having to eat all the leftover sugars, causing gas and discomfort (not fun!).
Now what about fiber?
Fiber is technically a complex carb too. It contains 1000’s of glucose sugars (and maybe some other things too). However, the way the glucose molecules are attached is very different than they are for starches. The enzymes in your small intestine cannot break these molecules down because their bonds are too strong.
This is why we like fiber. Fiber doesn’t get broken down into tiny sugars, but just keeps moving through your digestive system. Because of this, it actually helps slow the process down, and gives your body a chance to break down other things more effectively, so they can be absorbed at slower pace (avoiding that high blood sugar spike!). It also attracts water to your intestines, helping things move along too. This is why you are told to eat fiber to help your digestion. It just helps to “keep things moving.” Which, is what you want.
So, eating an apple vs. a candy bar is different because an apple contains fiber (and vitamins and other good stuff too!). The fiber in the apple slows the body’s ability to absorb sugar, delaying it from entering your blood. However, the sugar from the candy bar just absorbs directly into your blood (blood sugar spike!), plus it has no other nutrients. Yes, you are still getting sugar from both, but since an apple has other helpful things in it, its actually better for you.
The same principle applies to white bread vs. whole grain brain. The whole grains still have their fiber intact (plus other nutrients!), and the white bread does not.
All the sugar you eat, whether its from a simple (sugar) form or a complex (starch) form, enters your liver. Your liver than decides on what to do with it. It sends some to your bloodstream to be used by your body for energy. It stores some of it (for when you need energy later), or it converts it to fat.
You body only needs so much for energy purposes. And your body will never waste anything, it thinks it can use later. It loves to store fat. That is why any extra sugar you eat, will get converted to fat. That’s just your body’s survival mechanism. Unfortunately, this fat (too much of it over time), can lead to problems, like obesity, heart disease and diabetes. This is why we need to be careful.
So, how do you know if you are eating enough carbs, or too much? Well, first: Are you gaining excess weight (or having trouble losing excess weight)? Do you feel bloated or uncomfortable after eating something that is too sugary or carby? Do you get “sugar highs” and then “sugar crashes?” Another symptom, I’ve noticed is heart palpitations after eating too much sugar. Too much sugar can also wreck havoc with your hormones (leading to acne, or even fertility problems overtime). Brain fog, poor sleep, and just lack of energy are also signs of too much sugar. Basically, you need to watch your physical symptoms after you eat. Everyone is different and there isn’t a one size fits all. The best way is really to just pay attention to your body’s cues. If you think you are eating too much, cut back and see what happens. (Be careful because your body can literally go through a sugar detox, which can take some days to work through). Also, if you cut back on carbs, your body will be looking for an energy source: healthy fats or protein need to be added to compensate.
If you still are unsure, let me know! That’s my job is to help. Unfortunately our society makes eating healthy very difficult. It’s also a very sugary world out there. I can help you navigate it.
What’s your experience with eating carbohydrates or sugar? Do you feel low carb is better for you? How do you navigate this sugar world? I’d love to hear your experience!