value of a metabolic test

Today I had my first metabolic test done at the gym to figure out my BMR, and to figure out my maintenance calories based on my daily activity level. My BMR was determined to be 1443 calories, which is close to MFP's calculation of 1383. On the other hand, the maintenance calories were way off, and I found out I should be eating ~200 calories more every day. Each person has a unique BMR so I think it's worthwhile to get a metabolic test done. I received a printout afterwards which provided a lot of useful info, and the main points are written out below (references are provided at the end):

--Most equations to calculate BMR use basic demographics (including weight, age, height, and gender), and assume that everyone has a similar metabolic rate. They do not factor in physiological changes such as hormones, genetics, and improvements in lean muscle mass.

--Studies have shown that there can be up to 35% variance between estimated and actual. The best equation used is incorrect 70% of the time, and it can be off by as much as 10%. What does this mean? If your predicted (calculated) daily intake is 1500 calories, 10% error means eating 150 more calories. In one month, this adds up to 4,500 calories. So you can anticipate weight gain of about 12 pounds/year.

--In a study by Foster et al., predicted and actual BMRs were determined for 80 people of the same height and weight. The predicted value was around 1743 for everyone. For the 5 people who were featured in my printout, the actual BMRs ranged from 1263-2152. That study was really convincing for me. If your actual BMR is considerably higher than MFP's predicted value, then you will eat less than you should, and with this sustained pattern, your body will probably hold onto the fat and start burning muscle

--The gold standard that can accurately establish individual energy intake levels is by measuring oxygen consumption (VO2) and oxygen expression (VCO2) (this is the test that i did today - where you wear a mask that hooks up to a machine, and breathe in and out through your mouth)

--The American College of Sports Medicine has written in its position paper "Appropriate Interventions for Weight Loss" that "It is recommended that an individual level of energy intake be established."

Admittedly, there are a lot of estimates involved in weight loss: our BMRs, daily activity level, calories eaten, exercise calories burned, etc. But I think that finding out your actual BMR is probably the most important info you will need, and it helps set the stage for everything else. It's just something to consider, but either way, happy metabolizing, everyone!


*References*

--Foster GD et al. Resting energy expenditure, body composition, and excess weight in obese. Metabolism 37(5):467-72, 1988
--Frankenfield DC et al. Validation of several established equations for resting metabolic rate in obese and nonobese people. Journal of the American Dietetic Association 103(9):1152-9, 2003
--Jackicic JM et al. American College of Sports Medicine position stand. Appropriate intervention strategies for weight loss and prevention of weight regain for adults. Medicine and Science in Sports and Exercise 33(12):2145-56, 2001
--Weir J. New methods for calculating metabolic rate with special reference to protein metabolism. Journal of Physiology 101:1-9, 1949
--ACSM's Guidelines for Exercise Testing and Prescription, 6th edition, 2000; p 215-6