Originally Posted by Duathiel
in the activity log, when i customise an activity, what is the Mifflin method and what is the Harris-Benedict method? Does it matter which one i choose? Also what IS baseline metabolism?
Great question! I had it too a while back, so did some research. The methods listed are actually Predictive Equations, which means they are mathematic estimates used to figure metabolic rates, instead of hooking someone up to various machines during sleep and exercise to determine how that specific body is using energy. Maybe you have seen pictures of people on exercise treadmills, with heart monitor leads and breathing equipment that look more like vacuum cleaner hoses?
The Harris-Benedict was developed in 1919, and others have done their own version of the calculations they believe are more accurate. There is the Adjusted Harris-Benedict, and the Owen, and the Mifflin, among others. To determine overall accuracy in predicting metabolic rate, the calculation is done, then compared to actual maeasurements with the metabolic equipment for many different people.
The Miffin is believed in some circles to be the most accurate, especially for people who are considered obese (Body Mass Index BMI=30 and higher). The reason for this is that the calculations themselves do not take body composition into account--they only ask gender, age, weight & height. To say this more simply, a body type with more muscle will burn more calories just to stay alive, than will a body with a higher amount of fat stores. The mathematic calculations have no way of having you input the % of your body weight that is muscle, and the % that is fat. The calculations will show a lower number of calories used (than is actually needed) for someone with alot of muscle and very little fat. And the reverse is true, that someone with alot of fat will see a calculated BMR with an inflated number of calories needed to stay alive, when the actual number is lower (because fat doesn't use calories).
The best way to use these numbers for weightloss IMO, is to use the Miffin method, then increase it with general activity level (sedentary up to very active) without regard to any exercise done...just reflecting life in general. Don't eat more than this amount of calories, and you will not gain weight...but you won't lose either. Then as long as you exercise, and eat as though you are NOT doing the added exercise, you will lose consistently and safely. Strength training, instead of just cardio, is important here because strength training makes the body use more calories just to stay alive in order to repair muscle tissue after the workout, in addition to the calories used during the workout itself.
If you are unable to work out for that day, you have not eaten calories already that will cause you to gain...just stay the same. Also, you are not eating dangerously low numbers of calories that your body will see as insufficient for life to continue, which will damage your metabolism if done very long. The body is very smart, and knows what to do to support life--it's called reduce metabolism, sacrifice muscle tissue, and hold onto as much fat as possible. Resources seem to agree that a woman should not go below 1200 calories per day without direct medical supervision to keep her body from shutting down.
Remember, this is just my opinion, based upon my own research. It's working for me. Do what your doctor or other health professional suggests for you specifically.