The quick and short answer is our bodies burn fat when we expend more calories than we consume, but as you know I don’t focus on calories. Rather, I focus on the macronutrients. Nevertheless, let’s take a look at what really happens inside when fat-burning is taking place.
Glycogen versus Fat
When we eat and the food is digested, carbohydrates are converted into glycogen and stored in the liver. Our bodies use glycogen for energy, and the liver releases glycogen into the bloodstream as needed. If the body does not have glycogen to burn, the body uses fat for energy. Burning fat as energy is referred to as ketosis. The liver will also convert protein into glycogen, however, it does it in a way that it has little or no immediate impact on your blood sugar.
Fat Activated for Energy
In the fat tissue, there is an enzyme called lipase. When there is no glycogen to use as energy, hormones that regulate blood sugar activate lipase to release triglycerides in the fat cells into the bloodstream. Triglycerides are what make fat cells, well…fat. The liver extracts glycerol from the triglycerides released into the bloodstream and converts them to energy. If triglycerides sound familiar, that’s because an abundance of them can lead to Metabolic Syndrome which increases your risk for heart disease, diabetes, and strokes. This process of breaking down the triglycerides is called lipolysis. It is the release of the triglycerides from the fat cells that reduces fat in our bodies.
How Do You Activate Fat for Energy?
It’s a simple, but not an easy solution:
Studies continue to show that resistance or weight training is the fastest way to burn fat. The more muscle you have, the more effectively your body can burn fat.
Sprint Interval Training
In a 20 week study comparing HIIT versus a more traditional endurance training (ET) where all participants used a recumbent bike, those in the HIIT group lost 3 times as much fat as the ET group while expending less than 1/2 the calories.
Low Glycemic Diet
Our bodies have a hormonal response to food. Getting your macronutrients (proteins, carbohydrates, and fats) from good sources is the key to effective weight loss. In particular, eating foods that don’t cause an immediate spike in insulin such as refined sugars that are prevalent in many processed foods and liquids will motivate your metabolism to burn fat. Getting your carbs from low glycemic sources, like vegetables and fruits, trigger a much slower insulin production and release.
As always, I encourage you to join the conversation by posting a comment below or sharing this with someone.
Good health to you,
- Fat Burning Secrets – Richard Webb
- Glycemic Index of Proteins – Livestrong.com
- What are Triglycerides? – WebMD
- Impact of Exercise Intensity on Body Fatness and Skeletal Muscle Metabolism – ExRx.net
- Metabolic Syndrome – Mayoclinic.org