Carbohydrates are a collection of molecules. There are a variety of interesting facts and statistics about this nutrient category.
While there are still many uncertainties about carbohydrates, at the same time there are also many well-known facts.
Most of the findings below are relatively certain but with the surveys and polls you need to keep in mind that these are estimations from a smaller group of people.
Additionally, remember that due to individual differences like genes, two people can eat the same carbohydrate-rich foods but experience different consequences.
1. What are carbohydrates
Carbohydrates are the name for a collection of molecules with certain properties. More specifically, molecules that consist of carbon (C), hydrogen (H), and oxygen (O).
This term is so popular because carbohydrates are extremely common in a typical human diet. The research around these nutrients is also not entirely clear yet so carbohydrates are still a widely discussed topic that gets a lot of attention.
One of the things that complicate this topic even more is the fact that two different people can react differently to the exact same foods.
2. One of the three macronutrients
Macronutrients are certain nutrients that people consume a lot of and are a source of energy. The three main ones include carbohydrates, protein, and fats.
1 gram of carbohydrates contains about 4 calories, 1 gram of protein contains about 4 calories, and 1 gram of fat contains about 9 calories (1).
The main function of most carbohydrates in the human diet is to provide energy. Fiber, a certain form of carbohydrates, has other important functions as well.
Protein and fat can also provide energy but are also important for things like creating muscle and hormones.
3. Different ways to categorize carbohydrates
Within this big category of molecules it is possible to make different subcategories. For the average person this is an important fact since different types of carbohydrates have different effects on human health.
The first way you can divide up carbohydrates is into sugars, starches, and cellulose (includes fiber).
Next, carbohydrates are commonly divided into monosaccharides, disaccharides, oligosaccharides, and polysaccharides with these names indicating what the chemical formula is.
For the average person a simpler way to categorize carbohydrates on a spectrum from complex to simple.
Complex indicates that the carbohydrates are harder to break down. Examples include fiber and some of the other long-chain carbohydrates. These are generally found in vegetables and whole grains.
Examples of simple carbohydrates are white sugar and refined grains.
For optimal health, most people generally want to choose the more complex carbohydrates.
4. Recommended carbohydrate intake
The Dietary Guidelines for Americans for 2020-2025 recommends certain foods with carbohydrates. For an individual on a 2000-calorie diet they recommend the following quantities (2):
- Vegetables (includes leafy greens, legumes, starchy vegetables, etc.): 2.5 cups per day
- Fruits: 2 cups per day
- Grains: 6 ounces per day (at least 3 ounces of whole grains)
Additionally, they recommend keeping the number of calories from added sugars less than 10% of total calories.
Keep in mind that these are very rough recommendations. In reality, the best diet for you personally will depend on a lot of different factors.
5. Trends in carbohydrate intakes USA
The negative health effects of excess sugar intake are becoming more and more well-known. You may wonder if this also leads to less carbohydrate consumption in the general population.
One report based on surveys with U.S. participants looked at the percentage of daily calories that were consumed in carbohydrates from 1988-2016.
They concluded that from 1988 – 1994 this was about 49.8%. In the period of 2013-2016, the estimations are 47.3% (3).
In 2013-2016 the percentage of calories from protein was estimated to be 16%, for fat 34.8%.
The obvious downside of this report is that it does not include any statistics about the types of carbohydrates, protein, and fats. These facts are very relevant when it comes to health.
6. Glucose tolerance is better in the morning
Glucose tolerance can be described as how well your body can return your blood glucose levels to normal levels after eating foods with carbohydrates.
Interestingly enough, this capability is one of the processes in the human body that is influenced by circadian rhythms. In simple words, influenced by how late in the day it is and how late your body thinks it is.
The human body has better glucose tolerance in the morning. This difference is so relevant that an individual with “normal” glucose tolerance in the morning is metabolically equivalent to being prediabetic in the evening in some cases (4).
Having blood glucose levels that are too high can lead to a variety of negative effects on your health.
So if you don’t care about the difference in timing, you would preferably eat your foods high in simple carbohydrates in the morning, not in the evening (or even better not at all!).
7. Your body can make carbohydrates
Many people like to use that some processes in your body require glucose as a reason low-carb diets could never work. However, your body is actually able to make glucose (=carbohydrates) from other substances.
This process is called gluconeogenesis and uses substances like amino acids (from protein), lactate, glycerol, and odd chain fatty acids (5).
Even with that fact in mind, most people still benefit in terms of health from carbohydrates like fiber that can not be made by the human body.
Because of this and other reasons most people want to consume at least some amount of carbohydrates for optimal health.
8. There are foods without carbohydrates
Many foods in a typical human diet contain at least some form of carbohydrates. That being said, there are also a good amount of options without carbohydrates.
The main food group examples of this are oils, meat, seafood, and a few zero-calorie drinks.
More specifically, some examples include olive oils, coconut oil, salmon, beef, tuna, lamb, sardines, chicken, shrimp pork, eggs, oils, coffee, green tea, etc.
The opposite, foods without protein or without fat, is a lot rarer. One example is pure sugar.
9. Whole grains vs refined grains
You may have heard that you should focus on eating whole grains, not refined grains and the products made from them, to improve your health.
Whole grains still have all of their parts which include the bran, endosperm, and germ. Refined grains are processed in a way where the bran and germ have been removed. All that is left is the endosperm.
In terms of health benefits, this is unfortunate since the bran and germ contain valuable nutrients like fiber, phytochemicals, vitamins, and minerals.
The endosperm that is left is relatively high in short-chain carbohydrates and not that high in protein, vitamins, minerals, and fiber. This adds a lot of calories and raises your blood sugar a lot without offering many benefits.
Compare that to whole grains and the choice is clear if you want to pick the healthiest option.
10. Worldwide production of sugar
Sugar is one of the carbohydrates with the shortest chemical chains. This can be helpful for goals like getting some short-lived energy but is in general not good for your health.
Even so, the human body tends to crave these simple sugars a lot. The result of this is that sugar is widely produced and consumed.
One source estimates that the total worldwide annual sugar production is 179.86 million metric tons (6). To emphasize how much this is, this is equal to 179.86 million x 1,000 kg (2,205 pounds).
The same source estimates the United States produced 8.4 million metric tons of sugar in 2020.
Important to note about these statistics is that this sugar is not all for human consumption. Even so, that is still a lot of simple carbohydrates.
11. Your body can store carbohydrates
When you eat foods that contain carbohydrates, your body breaks these carbohydrates down to glucose. However, too much glucose is not good for you either.
Luckily the human body can convert excess glucose into a substance called glycogen. When/if needed the human body can then convert this glycogen back into glucose.
One publication estimates that a fasted, healthy 70-kg (154.3-pound) human can store between 100g and 400g of glycogen (7).
12. Carbohydrates increase water weight
Low-carb diets can definitely help you lose fat too but a part of the initial weight loss of these diets is water loss. This is because carbohydrates, more specifically glycogen stores, increase the amount of water your body holds on to.
In general, 1 gram of glycogen is bound to 3 grams of water (8). If a person has glycogen stores of 400 grams that would lead to an extra 1.2 kg of water.
If you consume even more carbohydrates without reducing your glycogen stores, the excess glucose gets turned into fat. That means there is a limit to the extra water weight.
This works the other way too. You can only reduce your glycogen stores, and thus the water weight related to this, a certain amount.
13. You can estimate blood sugar increases
With all these differences between complex carbohydrates, simple carbohydrates, different chemical chain lengths, etc. the impact these foods have on your body can feel unpredictable.
And while there are still many unknowns when it comes to nutrition, there are at least ways to estimate how much certain foods with carbohydrates raise your blood sugar compared to other foods.
The first way is the glycemic index. This is a collection of foods with how much this food raises your blood sugar 2 hours after eating (after a 12-hour fast) a certain quantity (50 grams of carbs in total).
Each food gets a “score” from 0 – 100 with 100 being the effect of pure glucose.
Secondly, there is the glycemic load which takes the typical portion sizes into account. This glycemic load is calculated by multiplying the grams of the food x the food’s glycemic index and then dividing by 100.
This second estimation method is generally more realistic. For example, watermelon has a glycemic index of 80 but in normal portions, this food does not raise your blood sugar that much.
Lastly, there is the insulin index. This is similar to the glycemic index but uses food in portions of a certain calorie count (240 calories) and measures how much foods raise the hormone insulin.
14. Carbs can improve explosive workout performance
While the health effects of the different macronutrients are not entirely clear yet (and likely vary a lot between individuals), many people agree about the functions of these nutrients in workouts.
Carbohydrates tend to be the best fuel for performance in high-intensity workouts (9). Fats tend to be thought of as a helpful fuel source for lower-intensity exercise for longer durations. Protein is important in both cases.
15. Percent of your body that is carbohydrates
Similar to other animals, only a small, negligible amount of your body is made of carbohydrates. Encyclopaedia Britannica estimates less than 1 percent (10).
About 4 grams of glucose circulates in the blood of a healthy person weighing 70 kg (154.3 pounds) (11). By now it is clear that this can vary but that typically the human body is hard at work to keep it around this level.
