Metabolic Flexibility: Why It’s Important by Jerry Brainum 8/23

 

Metabolic Flexibility in simple terms refers to an ability to switch to different fuel sources as needed. Having a high degree of metabolic flexibility (MF) provides the advantage of being able to maintain maximal energy during either caloric restriction or excess and also maintaining maximal energy production during exercise and sports. Clearly, the importance of MF is obvious for anyone involved in exercise or athletic activity. Another way of viewing MF is having the ability to match energy needs with activity. At its most elemental level, MF refers to a rapid ability to switch from using carbohydrates as a major fuel source to tapping into fat stores. This should be the norm in how the body works, but because of bad habits such as lack of physical activity and poor nutrition, MF is lost, which can lead to various serious health problems. From the viewpoint of exercise, lacking MF means an inability to burn stored fat efficiently. A person with MF will rely more on carbohydrates, and while carbs are a readily used fuel source, once they are depleted, energy will decline significantly. With a high degree of MF, a person can eat healthy carbohydrate foods without worrying about the carbs converting into body fat, and the same is true for fat. While dietary fat is often characterized as the most fattening source of calories at 9 per gram, with MF fat is readily used as a fuel and is far less likely to be stored as body fat.

Having MF offers the ability to eat a greater variety of food without having to worry about body fat gains. Consuming a greater variety of food ensures better nutrition and health because of the provision of more available nutrients in the food. While many diets focus on a reduction of either fat or carbohydrates, having greater metabolic flexibility means that the macronutrient content of the diet is less important because you can more efficiently use any type of nutrient, both fat and carbs. This doesn't mean that you can eat as much food as you want with impunity. While increased metabolic flexibility does mean less risk of obesity because of an increased ability to switch to fuels as needed, overeating or consuming far more food in relation to physical activity will still lead to an increased risk for added body fat. Ironically, eating too much also produces metabolic inflexibility, which makes the situation even worse.

One great advantage of metabolic flexibility is that food cravings are greatly decreased. That makes staying on any type of diet far easier. One of the causes of metabolic inflexibility is insulin resistance. As the name implies, insulin resistance involves a decreased efficiency of insulin to process carbohydrates and promote their entry into cells. Insulin resistance is widespread, with millions of . . .