Bloating, carbohydrates, and calories
Carbohydrates, commonly referred to as carbs, are combinations of an assortment of sugars that may or may not benefit your body.
It’s impossible to go very long before you hear someone talk about high fructose corn syrup, no matter which side of the argument they embrace. It’s also impossible to escape television advertisements about prescription and over-the-counter medications to relieve bloating, gas and other gastrointestinal (GI)or gut discomforts. Because, pharmaceutical companies would like us to believe that “there’s a drug for that”, along the lines of what Apple trademarked back in 2010 — “There’s an app for that”. Indeed, there are drugs that do alleviate some GI discomforts, but perhaps it would be helpful to look at some of the reasons that might cause these discomforts.
All living cells, whether plant, animal, yeast or bacteria, are essentially bags of water that contain an amazing mix of molecules each one as important as the next. These bags sometimes have smaller bags inside them, each also containing a mix of molecules.
Biochemists and chemists have made our lives easier by a broad classification of these molecules into categories, some of which are protein, lipid, carbohydrates, and nucleic acids. Nucleic acids are what make up your genetic material, and at a very basic level carry the instructions needed for a cell to stay alive. Proteins, perhaps the most versatile molecules in a cell, wear many hats — from helping your genetic material do the right thing, to keeping track of the traffic into and out of a cell. Lipids, colloquially referred to as fats, depending on their chemical nature are sometimes reserves of energy, sometimes molecules that carry signals from one molecule to another, or even simply mark another molecule so that it’s function is now specialized; they also help to maintain the integrity of the boundaries of the aforementioned big and small bags. Carbohydrates come in many varieties and while also being reserves of energy, like lipids they too can mark other molecules so that now with these marks there is twice as much diversity, and therefore twice as much functional capacity: sometimes these “marks” act like on/off switches.
These basic generalizations apply to all living species. Since all these molecules are primarily made up of atoms of carbon [C], hydrogen [H], oxygen [O], nitrogen [N], sulphur [S], or phosphorus [P] in a range of viable combinations, there can be variations in how they appear in different species; and each species has biological mechanisms to handle their specific form of these molecules.
What are calories and what do they mean on a food label?
Calories on food labels tell us how much energy that food provides in the indicated serving. The word “calories” is used as a shorthand by many to indicate something that contributes to body weight, as in: “soda has too many calories, it will increase my weight.” Indeed, food that can be stored as energy reserves in your body — one reserve being fat — can contribute to increased weight.
In the US, food labels have the word “Calories”; in other parts of the world, the label might indicate “kcal” — they are equivalent— 1 Calorie=1 kcal (1 kilocalorie). A Calorie (also called a large or big calorie) is the amount of energy required to raise the temperature of one kilogram of water one degree Celsius and is equal to 1000 small calories. [Note that most US companies in the food business, and even recipe book publishers, buck scientific guidelines when they use a lowercase “c”, confusing consumers who take the time to read labels and understand them. So if a recipe/label says a serving has 70 calories, it should really read “70 Calories”, or if there is a deep attachment to a lowercase “c”, it should read “70 kcal”.]
A food source’s calories can come from more than one component in the food. In other words, Calories in a piece of chicken can come from the carbohydrates, fats and proteins in that piece of chicken. While 1 gram of protein contributes 4 Calories (or incorrectly denoted as 4 calories) as does a gram of carbohydrate; a gram of fat contributes 9 Calories (or incorrectly denoted as 9 calories). What this really means is that when you eat a gram of protein, it is digested and then stored in the body in a different form; that form has the potential to provide 4 Calories of energy. Carbohydrate digestion begins right in your mouth, and continues through the intestine; protein digestion is primarily in the stomach; and digestion of fats occurs mainly in the intestines.
Now, about those carbohydrates
The most common simple carbohydrate we consume is sugar or sucrose, which is a combination of two simple sugars — glucose and fructose — if you put a teaspoon of sugar in your tea or coffee, it’s equivalent to half a teaspoon of glucose and half a teaspoon of fructose. Sucralose (sold as Splenda and other trademarked products) is a modified version of sucrose, where three of the hydroxyl groups (denoted by OH in the figure below) are replaced by chlorine (Cl) atoms (marked with red asterisks in the figure), through a series of chemical reactions.
Both glucose and fructose have the same number of carbons, hydrogens and oxygens, yet the atoms are arranged differently, where glucose ends up in a hexagonal form, and fructose in a pentagonal form. It’s said that in architecture form follows function; in biology the two are inextricably linked. Consequently, there are some places in your body that glucose can reach much faster than fructose.
Also, because their shapes are different, when glucose and fructose are broken down in the body, they yield different products. Further, because of the slower movement of fructose through the digestive tract, it has a greater possibility of being acted upon by normal gut bacteria which produce a variety of different gases that can contribute to feeling bloated.
The story of fructose is complicated by the fact that fructose can also exist as a polymer — several units of fructose strung together with one end usually a unit of glucose. This polymer is called fructan, and humans have a limited ability to digest fructans. Of course, the fraction that is digested leads to free fructose which as described earlier, can contribute to bloating. Fructans are found in a number of common foods like leeks, garlic, onions, wheat, artichokes and asparagus, to varying degrees. There have been a number of research reports that correlate bloating with high consumption of fructans and not just gluten, resulting in the recognition of fructan intolerance. In fact, patients with mild irritable bowel syndrome (IBS) sometimes find relief when reducing or eliminating consumption of fructan-rich foods. If fructan-rich foods are really ones you’d like to have every so often even in the face of fructan intolerance, cooking/sauteeing them extensively in oil before adding water is sometimes helpful: fructans are water-soluble and will not leach out in oil.
And then there are the FODMAPs
FODMAPs are Fermentable Oligo-, Di-, Mono-saccharides And Polyols. “Saccharides” are sugars — this includes the monosaccharides like glucose and fructose; disaccharides like sucrose; and polysaccharides like starch. Polyols include substances like PEG (polyethylene glycol) that you might find as an additive in some medicines, and xylitol found in many packaged foods. Foods high in FODMAPs can promote bloating because of the reasons described earlier, so if you’ve got an issue with bloating don’t ignore the labels of packaged products and medicines, but also seek out low FODMAP foods.
Although there is a slow but perceptible change in eating habits, where consumers are more aware of what goes on their plates than ever before, we are often woefully lacking in our understanding and appreciation of the science behind some of our food-related discomforts. Certainly, what you ingest might not be the only reason you experience bloating, so seeking medical attention for persistent bloating is a good idea. Because there’s probably a remedy for that!
