Most people have probably heard that weight loss or weight gain comes down to “input vs. output”. While most people understand the input side of the equation-the food you eat-many do not appreciate or understand how your body expends calories on a daily basis. By understanding energy expenditure and metabolic rate, meeting and maintaining your weight and body composition goals becomes much more likely.
What makes up your Metabolic Rate?
1. Resting Metabolic Rate (RMR): the energy needed to sustain the body’s most basic functions (heart beat, respiration, all the processes on the cellular level, etc) and is responsible for 50-70% of the calories you burn on a daily basis. Many people don’t understand that even if they were to sit still all day long in a chair, their bodies would still be expending a significant amount of energy. To get a rough estimate of your resting metabolic rate, simply multiply your body weight by 10-11.
RMR is greatly influenced by the amount of lean muscle tissue you have: those who carry and maintain more muscle tissue will expend more calories than someone who has less muscle tissue. Bottom line: if you want to prevent a decline in resting metabolic rate as you age, don’t lose muscle mass. Consistent strength training is the best way to accomplish this.
2. The Thermic Effect of Food (TEF): the amount of calories used by the body while processing, digesting, and absorbing the food you eat. Generally, TEF makes up about 10% of the calories expended by your body daily if you are eating a typical mixed American diet. If you eat a 400 calorie cold cut sandwich, you really only take on about 360 of those calories.
Now, you can use TEF to your advantage when trying to lose weight and fat. Of the 3 macronutrients (protein, carb, and fat) protein has the highest TEF: of the total amount of protein you eat, 20-30% is lost in processing. So, if you look at your total calorie intake, if you increase the percentage of protein you are eating, your body will burn more calories. Over time, this can potentially lead to a few more pounds of weight lost.
3. The Thermic Effect of Activity (TEA): this is all the energy you burn outside of your resting metabolic rate through physical activity. Going to the gym to workout is TEA. Getting up from the couch and walking upstairs is TEA. Doing chores or yard work? This is also is TEA. So, basically, any bodily movement which expends energy. TEA is highly variable depending on the individual. Due to the sedentary nature of our society, and the large number of professional desk jobs, most people don’t burn up a lot of energy through TEA. People who work manual labor jobs burn a lot more calories through TEA: they are burning a lot of energy passively without having to set aside an hour to go to the gym specifically to burn calories.
4. There is also a sub-category of TEA which includes “fidgeting”, and other types of spontaneous movements which don’t really accomplish much (also referred to at NEAT...non exercise activity thermogenesis). We all knew someone in grade school who had “ants in their pants”…this is what I’m talking about here. Those people who can’t sit still, who are always tapping their foot or bouncing their knee, etc. actually can burn very significant amounts of energy, up to 900 calories per day.
I hope this article provided you with a nice overview and better understanding of metabolic rate. Of the four components of metabolic rate outlined above, see which areas you could improve upon or manipulate for better fat loss results...now get to work and apply this information!