Energy for life comes from the oxidative processes that break our food down. This process of “burning” food as fuel for movement or enzymatic processes generates heat.
Body heat is tightly-regulated by our central nervous system since cellular functions are most efficient at 98.6 degrees Fahrenheit. When our bodies are in disarray from illness or infection, we get an elevated temperature (fever).
The rate at which we breakdown macronutrients or stored calories is considered our metabolic rate. The higher our metabolic rate, the faster we burn calories from food or stored fuels, like fat.
We have a “basal metabolic rate”, which is the rate at which we burn calories to keep essential functions like the heart beating and the brain “on”. Our “Resting Metabolic Rate” or RMR is the amount of calories burned during a state of rest, lying down, and inactivity. Sometimes, basal and resting metabolic rate are considered the same, but there are differences that scientists like to point out.
A number of factors may influence our metabolic rate. First, the food we eat affects it. As soon as we start to eat we really aren’t resting. It takes some energy for sitting up, chewing, and shoveling our food. It’s worth bearing in mind however, that not all foods and calories are created equal in their ability to affect our metabolic rate. For instance, a high protein meal results in more energy expenditure than a high carbohydrate meal. This is partly due to what is called the “thermic effect of food.” It is very interesting that just the act of eating protein burns more calories than eating carbohydrate.
Further, the environment affects our metabolic rate. Studies have shown that lowering the room temperature from 70 degrees to 65-67 degrees Fahrenheit may increase your metabolic rate.
Interestingly, ingredients in some thermogenic supplements, such as Beyond Raw® Neuro Shred™ have this ability as well. In particular, capsaicin, a pungent compound of red chili pepper, is a thermogenic ingredient which stimulates energy expenditure. Capsaicin increases fat oxidation, limits appetite, and increases energy expenditure.
Although some of these effects appear to be through SNS stimulation, capsaicin also has little effect on blood pressure. Interestingly, capsaicin supplementation appears to limit the decline in metabolism that occurs with calorie-restricted dieting.
The interactions of our food, our environment, and our hormones make studying metabolic rate very challenging.
The take-home from this discussion is that there are many factors which may affect our metabolic rate. Having a healthy diet focusing on adequate protein intake, use of quality supplements, and care to maintain healthy body temperature may be some of the interventions for maintaining our metabolic rate.
