Get the Skinny on Carbs
When it comes to nutrition, the topic of carbohydrates is one of the most often discussed… and one of the most confusing. Should you avoid carbs and go “paleo”? Do carbs make you gain weight? How does the body use carbs? What foods count as carbs anyway?
The carbohydrates we eat get broken down into glucose, which is essential to life. Once glucose enters the bloodstream, the hormone insulin is primarily responsible for transporting glucose into the cells where it is used for energy. Glucose is the preferred fuel source for the brain and central nervous system.
Carbohydrates encompass a wide variety of foods including vegetables, fruits, grains, beans and legumes, pastas, breads, cereals, sugar etc. Looking at that list, it’s probably obvious that some of these foods will affect your body differently than others. The rate at which carbs are digested and absorbed influences body composition and health.
Refined carbohydrates such as sugar, pastas, potatoes, bread, and processed grains like packaged oats and white rice are broken down very quickly, and cause blood glucose (aka blood sugar) levels to spike fast. This is important to understand because your body prefers blood sugar levels to remain relatively stable. If excess glucose is present, the muscles and the liver are able to store some of it for later use. However, when this storage is full, additional glucose can be transformed into body fat. In addition, diets high in these types of refined carbs can lead to higher blood triglyceride levels, higher LDL cholesterol levels, and increased insulin resistance.
Carbohydrates that are digested and absorbed more slowly can help to control blood sugar and insulin concentrations, as well body composition. These types of carbohydrates are found in vegetables, fruits, legumes, and unprocessed whole grains. These types of carbs are the most important to eat daily, as they contain important vitamins, can help you feel fuller, and can help control energy levels. In addition, they also contain fiber which is important for digestive health, can lower cholesterol and can reduce your risk for certain cancers.
While legumes and whole grains fall into the “healthier” carbohydrate list, it is important to note that they do raise blood sugar levels more quickly than vegetables, and it’s pretty easy to eat a much bigger serving of these than you should. If you have a fat loss goal, eating these foods is best timed for after you do an intense workout (about 60 minutes of training where your heart rate is elevated and you are sweating). A serving size is about a cupped hand, or slightly more post-workout.
Speaking of workouts, let’s talk about how exercise affects the way your body processes carbs. After a training session, those storage supplies of glucose we talked about earlier could be depleted, and your body will prioritize using glucose broken down from the carbs you eat to replenish those supplies. Also, the muscle contraction that happens during and immediately following exercise facilitates the transfer of glucose into the cells even without insulin. This means your body has to use less insulin to transfer glucose, and is able to get the energy out of your bloodstream and into your cells more quickly, so there is less chance of excess glucose being stored as body fat.
So, keep it simple, and keep most of your carbohydrates coming from veggies, fruits, whole grains and legumes. If you have fat to lose, be mindful of the portion size of whole grains and beans, and ideally eat these 1-3 hours following a workout. Refined carbs like desserts, breads, pastas and crackers have their place – what would life be without pizza! Just keep these foods as a “splurge” 10% of the time, and if you can enjoy them following a hard training session, even better 🙂
Strength and love, Kati