Why You Crave Carbohydrates
- September 6, 2017
- Last Updated: September 18, 2021
- 9 Comments
- Nutrition
Hi friends! Today’s Wellness Wednesday post is all about carbohydrate cravings. This has come up in a few client sessions this week so I thought best to address is here, since other people probably have questions about it also.
First off, I will say that craving carbohydrates are not an inherently bad thing. In fact, most of our food supply is carbohydrates. Grains, fruits, vegetables, legumes, and dairy products all have carbohydrates in them. Plus, carbohydrates break down into our body’s most usable form of energy, glucose.
When clients or readers ask me wanting carbohydrates is normal, yes it is. Now, if you’re craving sweets 24/7, we probably would need to uncover some other parts of your eating style – past history, any food rules, forbidden foods, etc. But, craving carbohydrate foods makes the most sense biologically, because these foods are high sources of vitamins, nutrients and fiber. We can’t live without carbohydrates.
Let’s review how smart our bodies are. There can be reasons behind food cravings and aversions, sometimes. Our bodies do their best to communicate to us, but we’re not always listening or aware (read: We’re overly stressed, not sleeping enough and not in tune with our body).
NPY
Our brains have a chemical called Neuropeptide Y (NPY). While it is involved in many regulatory systems, including stress and and cardiovascular regulation, one of its main functions is appetite regulation. It is one (of many) chemicals responsible for our body’s drive to eat carbohydrates. Again, remember that carbohydrates are our body’s primary and preferable source of energy, so NPY is a good thing.
Our body will always do its best to maintain homeostasis, its normal, balanced idea of home. So, you can imagine if you try to override homeostasis, your body will try to resist and bring you to safety. For example, maybe you’ve sworn off all sweets or you decide to embark on a low carbohydrate diet. Well, food deprivation or any type of under-fueling will trigger NPY’s effect. In other words, these actions will cause the body to seek out more carbohydrates.
It’s kind of like the binge-restrict cycle that so many of my clients have been through.
You try your best to resist certain foods and end up craving them more. Well, here’s why.
If you’ve been restricting food (or carbohydrates in general), your body will attempt to catch up at the next eating event. This often results in a high carbohydrate binge (we rarely binge on fruits/veggies, or meat itself). It’s important to understand that this is not a failure or lack of willpower at work, it’s your body’s way of protecting you. It knows you need quick, instant energy. It also knows that for hunger, carbohydrates will satisfy you quickest.
When Does NPY increase?
We already mentioned how NPY increases after carbohydrate or food restriction. NPY also increases after an overnight fast. Therefore, levels of NPY are naturally highest in the morning because of the short term food deprivation. This is one of many reasons why you want to eat breakfast in the morning. If you ignore eating, NPY will continue to rise, which can lead to larger scale meals and binges (with less mindful choices) later in the day.
Consider a hard or long bout of exercise. You’re most likely relying on burning carbohydrates (and some fat) to fuel that exercise. As your carbohydrate stores decrease after exercise, NPY will rise. Because it is dependent on energy availability, it is upregulated with food deprivation or restriction, and returns to baseline levels after eating.
So, when we eat carbohydrates, we in effect turn off that NPY signal. Carbohydrates also increase the production of serotonin, which can also translate to a lesser craving or desire for carbohydrates. So basically, we’ll continue to crave carbohydrates until we know we have enough fuel or actually give our bodies carbohydrates.
Why Do We Need Carbohydrates?
I also think it’s important to talk a little bit about the biology and physiology of our body. So, glucose, which our bodies form from breaking down carbohydrates, is the main fuel for many of our cells. Specifically, red blood cells, the brain and our nervous system rely exclusively on glucose. We store some carbohydrates as glycogen in our muscles, but only our muscles can use that fuel.
So, if we’re in a fasted state or waking up from an overnight fast, we don’t have access to muscle glycogen. We store a limited amount of glucose in our livers, which is our main reservoir for fuel. When we run out of liver glycogen, that’s when our body has to find creative ways to make fuel. We can make glucose from breaking down muscle protein and amino acids in a process called gluconeogenesis, but it’s not very efficient. Plus, you don’t want to break down muscle, there’s many more devastating consequences that come with that. Your body doesn’t preferentially choose which muscles are broken down first. And your heart is a muscle – so if your body starts breaking that down, that can lead to death. That should be a last resort to situations when we really are starving.
Carbohydrates should be a part of every meal and snack you eat. I like to talk to clients about snack pairing. For example, string cheese and an orange, or nuts and raisins or pretzels. When you consume carbohydrates with something else, it helps better stabilize your blood sugar, leading to more energy, less highs and lows throughout the day, and longer satiety (lower NPY).
So, rather than swearing off carbohydrates, maybe you need to change the way in which you eat them. If you’re including them consistently and giving your body enough glucose to fuel until your next food meeting, you’re on the right track. But, if you’re avoiding carbohydrates and “saving up” until dinner, you’re likely to continue craving them because your body needs the energy. Or, you’ll go overboard at the next eating event. You’re not failing in willpower, your body is biologically hungry and is asking for fuel. Those are two totally different things.
I hope I’ve conveyed that our bodies rely on carbohydrates, and any craving for them is usually a sign that we’re running low or don’t have enough. Remember, undereating is a form of stress on the body, too.
I hope that helps bring some clarity. Feel free to send along any further questions.
Favorite snack? Lately, mine has been this bread with peanut butter.
Yasssss! I tell people this all the time. Of course, diet is personal… but I really don’t see how it an be healthy for one to stay in the “keto” state for months and months. It’s all about balance!
I hate that carbs always get a bad rep, because as you said, carbohydrates are in a lot of healthy foods, too… it just depends on WHAT you eat and that you get the complex carbs!
I loved how you explained all this.
Thank you for reading, San!
Great article Sarah, I learned so much 🙂 My favorite snack is usually a clifbar. Or PB with banana, classic.
Thanks Ellie! Both are classics 🙂
Wow this is fascinating; I didn’t know that this is why we crave carbohydrates, but that makes so much sense. I now know why I really want them especially in the morning, and I’m thankful that our bodies thrive on a balance of all the nutrients.
Our bodies are so smart. They never cease to amaze me.
Its very interesting that when any sort of binge occurs – its really never with meat or dairy or other type of fat or protein. Its always the pretzels and breads and chips.
Yes, very interesting. Our brains respond differently to palatable carbohydrate/fat foods.