Carbohydrates contribute a major part to the diet of most Americans.
The recommended intake of carbohydrates varies with lifestyle, depending on daily energy demands of each individual. Consuming excessive amounts of carbohydrates for those with a sedentary lifestyle, for example, can lead to increased fat storage. On the other hand, an athlete who is likely to have higher energy demands from exercise will benefit from the extra carbs.
Carbohydrates represent a major source of quick and latent energy for the body. Fermentation of carbohydrates, for example, is the preferred energetic pathway of skeletal muscle when in need of quick energy to meet physical demands. During heavy weight lifting, one forces muscle fibers to quickly ferment carbohydrates available to fuel mechanical work. Carbs also help maintain homeostatic points such as body temperature and blood sugar over extended periods of time.
Consuming too much or too little carbohydrates can have adverse effects on health. To help better understand why carbohydrate intake is so relevant, one must consider the body’s demand for carbs and how these demands change.
What are carbohydrates?
Carbohydrates are part of the four macromolecules in biology, along with protein, fat, and nucleic acids (like DNA and RNA). Simpler units compose the macromolecules which are far larger. These simpler units help define their shape and function. Carbohydrates are made of longer (sometimes branched) chains of sugar, which the body stores or consumes for energy.
When consumed, carbohydrates contribute to the generation of the energy molecule ATP (Adenosine Triphosphate) via energetic pathways both aerobic (oxygen dependent) and anaerobic (oxygen independent). Cells of different tissues throughout the body generate ATP. Mechanical work, as well as physiological function, require the use of ATP. For example, tissues found in skeletal muscle generate a significant amount of ATP in response to exercise.
How are carbohydrates used?
When digested, carbohydrates are broken down into simpler units to be used for energy or be stored away. Blood sugar is elevated after carbohydrate consumption and it is brought back down by a release of insulin by the pancreas. Insulin, in turn, promotes the storage of glucose in the form of glycogen in skeletal muscle and liver. Insulin also stops fatty acids released from adipose tissue to be used for the generation of ATP while promoting fat storage by activating lipoproteins (Acheson,1988). Liver glycogen is later used by the body when blood sugar drops below a desirable level. Glycogen stored in skeletal muscle is used to fuel and maintain physical activity for long periods of time.
Lifestyle Energy Demands
Modern lifestyles are predominantly sedentary and high in energy intake. Most diets consist of high levels of animal protein, carbohydrates, and processed high-energy foods and drinks. Consuming excess carbs for someone that doesn’t meet their energetic demands will result in weight gain and decreased glucose sensitivity. Due to this lifestyle, the incidence of obesity, heart problems, and metabolic diseases like type 2 diabetes is increasing. Over time, the progression of such conditions can end up in the loss of organ function and even death.
For those who have an active lifestyle, like athletes, consuming too little carbs can also present a problem. Exercise, for instance, requires a significant amount of energy to fuel movement and maintain it. Muscle glycogen, liver glycogen, as well as blood glucose all contribute to meet the energy demands of exercise on skeletal muscle. Low carbohydrate and glycogen levels are associated with fatigue during exercise and can affect performance. In such cases, sports drinks which are typically infused with electrolytes and carbohydrates can help replenish glycogen storages and sustain exercise for longer periods of time.
What To Do
Take lifestyle into account when thinking about carbohydrates and consume accordingly. If problems already exist due to an imbalance between lifestyle and diet, learn about it, consult an expert and begin making appropriate changes. Exercise, for example, has been found to be beneficial for individuals with type 2 diabetes as it promotes the movement of blood glucose into skeletal muscle to be used and increases glucose sensitivity (Mul, 2015).
If you would like to learn more about the effect of carbs in your diet, consult one our Nutritionists. If you want to increase your exercise to balance your carbohydrate intake to that our your energy needs, stop by CORE for one of our many fitness services!
Mul, Joram D, et al. “Exercise and Regulation of Carbohydrate Metabolism.” National Center for Biotechnology Information, 20 Aug. 2015, www.ncbi.nlm.nih.gov/pmc/articles/PMC4727532/#R5.
Acheson, K J, et al. “Glycogen Storage Capacity and De Novo Lipogenesis during Massive Carbohydrate Overfeeding in Man.” National Center for Biotechnology Information, Aug. 1988, www.ncbi.nlm.nih.gov/pubmed/3165600.