If you have seen any diet advertisements or watched the news you have undoubtedly heard about carbohydrates. Carbohydrates have been vital to the diet industry since the low-fat push in the 1990s. Carbohydrates have experienced a great swing in popularity, from the best nutrient for diet success to the reason for all the diet failures. This is a silly concept since one nutrient alone cannot make or break diet success.
What Are Carbohydrates?
Carbohydrates are one of the macronutrients that make up the foods we eat. They are commonly found in plants and plant products. Chemically, carbohydrates are simply organic compounds formed of carbon and hydroxyl groups. They form the structure of plants (cellulose) and animals (chitin and cartilage.) They also serve as energy stores (starch in plants and glycogen in animals.)
Carbohydrates are also called saccharides. The simplest form of carbohydrates are called monosaccharides. These include glucose, fructose, and galactose. Two of these monosaccharides together form disaccharides. Sucrose and lactose are examples of disaccharides. Oligosaccharides and polysaccharides have more monsaccharides bonded together. Oligosaccharides are chains of two to nine monosaccharides, while polysaccharides contain ten or more. Starch, cellulose, glycogen, and chitin are all examples of polysaccharides. Polysaccharides are also referred to as complex carbohyrates, while mono- and disaccharides are often called simple carbohydrates.
Carbohydrates are the most common energy source in the diet. They are easily digested and processed. While they are the fuel of choice for the body, especially the brain, many researchers have concluded that carbohydrates are not essential nutrients. The body can use fats, and to some degree proteins, for energy. Carbohydrates are not used in the repair and building of new tissue. They do however provide energy for storage in glycogen stores.
Carbohydrates are the energy source of choice for the brain. It requires glucose to function properly. The muscles also prefer glycogen for energy production, especially during short duration, higher intensity work. The body must break all carbohydrates down into monosaccharides (more specifically, glucose) to be used for energy production and storage. Insulin is required to transport glucose throughout the body and open receptor sites to accept the glucose. High levels of glucose in the blood triggers sensors to produce extra insulin to remove the glucose and shuffle it to areas where it is needed. First it goes to actively working areas that need energy, then to any glycogen stores that might be depleted, then any excess is shuffled into fat stores for future energy needs.
Complex Carbohydrates and Energy
While all carbohydrates are broken down into their simplest form for use in the body, they are not all equal. Simple carbohydrates, such as glucose, sucrose, fructose, and others, cause a rapid rise in blood sugar levels. This causes a spike in insulin production. The body will be able to produce a lot of energy at once, but the insulin quickly shuffles the glucose into storage to maintain an even level, but because so much is burned for energy while this is happening there is very little left for long term energy. So the sharp spike in energy after a sugary meal is followed by a drastic low.
Complex carbohydrates require more processing to break down into the simple glucose molecules. This means the glucose gets released into the blood stream at a slower rate. Insulin production does not need to increase and the energy levels stay the same. The glucose can be used as it is released and shuffled into glycogen and fat stores only if it is in excess. These complex carbohydrates provide energy for the long haul because they will be digested over a longer period of time.
Carbohydrates and Muscle
As stated earlier, carbohydrates have no direct function in repairing or building muscle. However, the energy they provide is essential for the repair and building process. And, as also stated earlier, carbohydrates are the energy source of choice for short duration, high intensity work. Weight training is certainly that. Carbohydrates are stored in the muscles as glycogen for just that purpose. When energy is needed for muscle contractions the glycogen stores can be used, after the ATP system is used up, to produce longer duration contractions.
Carbohydrates do not require oxygen to be used for energy, as is the case fat. They can be broken down and processed in the absence of oxygen, so they are an anaerobic energy source, well suited for strength training. The muscles appear flat and depleted when the glycogen stores are low. These stores pull water into the muscle giving it a fuller, rounder appearance.
Carbohydrates and Fat/Weight Gain
Carbohydrates in abundance can lead to increased fat stores. As explained, insulin is the transporter and key for glucose in the blood. It first takes that glucose to serve the immediate energy needs, then it is used to replenish lost glycogen in the muscles and liver, and finally, any excess left over is sent to the fat stores. So, high carbohydrate intake, above energy needs, results in excess calories being stored as fat.
Simple carbohydrates are the biggest culprit when it comes to fat storage. The resulting insulin spike causes much of the free floating glucose to be quickly shuffled to fat storage. Glucose, and insulin, has a high affinity for fat stores and is easily accepted in those stores. Insulin has to work a little harder to get the glycogen stores to open up for the extra glucose.
Slower digesting carbohydrates are a better choice for those trying to lose body fat. The even energy, and insulin, release results in less of the glucose being passed off to the fat stores. Fiber, soluble and insoluble, also aid in the digestion of other foods, while slowing the digestion of the carbohydrates, further helping reduce the amount shuffled to fat.
Carbohydrates, by nature, are neither good nor bad. They simply are. The good or bad part comes into play when discussing over-consumption, simple versus complex carbohydrates and timing, and overall energy needs. Insulin spikes, excess calories, and reduced energy needs can all result in the carbohydrates being moved to fat storage. Increased energy needs, even release of energy and insulin, and depleted glycogen stores will result in more of the carbohydrates being used and less going to fat stores. Carbohydrates are the preferred energy source of the body due to their easy digestion and processing. Don’t shun carbohydrates completely, but remember, “all good things in moderation.”