Understanding nutrition can be quite complex depending on your eating habits, fitness/health goals, hormone balance, and more. Simplifying the process by following basic rules, such as eating more vegetables at lunch, are a good start. However, some of you want to know exactly what you should be consuming for your goals. How many calories? Macros? Meal timing? It can become quite daunting. I’m a fan of using small steps to make big results. For those of you wishing to take your nutrition to the next level this means keeping it simple and not overcomplicating things. So, calories, the most important aspect of any diet IMO, should be known. Specifically, how many calories you burn while at rest (RMR) is important and simple.
HOW DO I DETERMINE MY RMR?
Find your RQ (respiratory quotient). The good news, you don’t have to do any work except breathe. The bad news, you have to find a facility that has a machine that can perform indirect calorimetry. If you live in a major city this will be easier to find than you expect (DEXAFIT has these machines throughout the country).
What happens when you get there? You sit in a dark room and bite down on a mouthpiece (attached to a computerized measurement device) with your nose pinched closed. The process takes about 15 min. During that time the machine is calibrating how much oxygen you consume and carbon dioxide you expend. The result is your RMR (assuming you’re sitting and relaxed à the system can be used for performance testing as well if you’re physically moving). The end result is your RMR.
WHAT IF I DON’T HAVE ACCESS TO AN RMR MACHINE?
The good news, you can figure it out for free! The bad news, you have to do some math. There are several formulas that can be used but the most accurate (with 70-80% accuracy) is the Mifflin-St. Jeor method:
RMR (kcal/day) = 10(body weight in kilograms) + 6.25(height in centimeters) – 5(age in years) + 5
Here’s my example:
RMR = 10(91kg) + 6.25(185cm) -5(33) + 5
RMR = 910 + 1,156 – 165 + 5
RMR = 1,906 kcal/day
See? The math wasn’t that hard. In order to be as accurate as possible with this formula is to remember your score can be off by an average of 20% (both up or down). When we factor in this error range my RMR can be as low as 1,520 or as high as 2,280/day. If you plan on using your RMR to help aid in fat loss or muscle gain then start with your RMR. Adjust your diet to fit these calorie amounts. As time passes you’ll notice if the amount you’re eating is helping or hindering your goals (as well as the quality of food).
STAY FIT MY FRIENDS!