I observed a conversation regarding whether a higher fat or a higher carbohydrate diet was better. The one has had great success in maintaining a low body fat percentage and having good energy throughout the day by eating a high fat diet. The other has had great success in achieving strength gains and having high energy during high intensity workouts by having a higher carbohydrate diet. This conversation got me interested in the different energy pathways the body uses and how to find a balance between what these two were saying in order to help people achieve their best results with the goals that they have.
Carbohydrate and fat are both food energy sources. In order for your body to use carbs or fat for energy, however, it must be converted to ATP, which is the energy currency of the cells. There are three primary energy pathways that the human body will use to convert our food energy into ATP depending on how quickly we need the energy.
The Phosphagen System is the fastest of the energy systems, used during short-term high-intensity activities such as a max effort deadlift or a short sprint. The phosphagen system uses creatine phosphate. Your body produces creatine phosphate using amino acids and can store a small amount in the muscles. Because there is a limited amount in the muscles, this system can get depleted very quickly. You might supplement with creatine in your post workout shake in order to more quickly replenish and even increase your creatine storages so you don’t fatigue as quickly.
The Anaerobic System is also used during high-intensity activities, but in those that are slightly longer, lasting between 30 seconds and three minutes. The anaerobic system requires carbohydrate and can replenish itself very quickly, assuming there is enough carbohydrate available in your system.
The Aerobic System is used during low intensity exercise and it can utilize either carbohydrate or fat. This is the system we’re most likely to spend the most amount of time in during every day life.
Carbohydrates are the preferred source of energy for your brain and your muscles. It’s important to note that after high intensity exercise, muscle cells are very insulin sensitive, which means your muscles will be likely to take up the carbohydrates consumed shortly after your workout. Outside of this exercise window, it’s typically the fat cells that are the most insulin sensitive, so they would take up the extra carbohydrate consumed throughout the day.
If your everyday life is more sedentary, it might be wise to consume most of your carbohydrate dense foods such as fruits and grains around the time you workout and have primarily vegetables, fats, and proteins the rest of the day. If you are very sedentary, vegetables should give you enough carbohydrate during the day to adequately fuel your brain and muscles and would help you to avoid fat storage.
If you are very active during the day, eating some slowly digesting carbohydrates might be more beneficial to you as following a higher fat, lower carb diet might leave you feeling pretty fatigued.
Overall, listen to your body. Monitor your intake. Be mindful of what foods you are eating have carbohydrates and which have fats. Pay attention to what your weight is doing from week to week (if that’s important to you). Make sure you are eating enough to support your energy needs but not eating so much that your body can’t use all the energy and ends up storing it as fat.