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Duathiel 01-15-2010 01:31 AM

Baseline Metabolism
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?

missmaggieelizabeth 01-15-2010 01:41 AM

Duathiel So glad you asked. I have been wondering the same thing.

Duathiel 01-15-2010 03:35 AM

and still no one knows....

showmenow 01-15-2010 05:56 AM

To my knowledge your baseline metabolism is/are the calories you burn from just being alive, to keep your organs functioning and to perform your normal daily activities. For instance if you get up, go to work and sit at a desk all day, come home, cook dinner, watch tv and go to bed. Nothing extra- just what you normally do in a day.

I don't know if there is a difference in the methods. I think I used the second one. It asked what kind of lifestyle I have. I sit at a desk all day so it was very sedentary. I don't burn near the calories that someone does who works in say a retail position, standing and walking all day. I was always envious of mailmen, ups etc. Can you imagine the exercise they get in a day??

Hope this helps!

missmaggieelizabeth 01-15-2010 06:05 AM

Thank you Showmenow. Makes sense.

pattyruns 01-15-2010 08:48 PM

I'm not sure the difference between the methods but I used the one that gave me the least and then went and customized it anyway. I went to a 'bodpod' which measures your muscle mass, baseline metabolism and body fat because I was not losing weight (you can google it for one in your area- about $70). I WAS losing inches however. I see a nutritonist who is also a doc and she recommended it to me.

Turns out I don't burn nearly the calories they gave me ( surprise!) so I customized it.

missmaggieelizabeth 01-16-2010 12:20 PM

That is me. Not loosing weight but I am loosing inches. Seems 14 inches over all should show some weight loss. AND I am NOT working out or lifting weights. Scratching my head over all of this. Not complaining I have lost inches. It just all seems so odd.I am confused.


sunrosa 01-23-2010 03:12 PM

There is a very slight different in the two methods of baseline metabolic calculation. My trainer used some method last year to calculate mine and came up with baseline of 1240 cals per day. So I do a custom here at Fitday and use her number for me.

Showmenow is correct. Your baseline is what your body uses just to stay alive with your normal, regular level of activity. So even if you work out hard at a gym in the evenings, or walk every afternoon, if you are sitting down at a desk all day (like me unfortunately - how did I end up here???), your baseline is lower than someone who is waiting on tables for example.

From what I read online, the differences between the two methods of calculation are insignificant for the general population. Only matters for hospitalized patients in nutrition calculation.

rockymtnsavvy 03-11-2010 01:16 AM


Originally Posted by Duathiel (Post 949)
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.

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