Nutrition - Weight - Calories - Oh its all just too much..... or is it?

21 to 25 of 25 messages
03/06/2011 at 10:24
Harris and Benedict's original research on energy expenditure, on which a lot of these formulas are based, was done in 1918!  Typical daily activity may have been rather different in those days
03/06/2011 at 10:27
agreed - I have not been down the mines yet today!
03/06/2011 at 21:33
I must be lucky with my metabolism then...
I'm a short small female, and generally have a leisurely swim in the morning - 45-60 mins, and then possibly a short run in the evening once or twice a week...
I also do a long and short bike and also swim at the weekend if not working.
Job is long hours and involves walking about but not any major exertion.
i don't sit still easily though.
I easily get through around 2500-3000 cals per day (more like at least 4000 on a long bike day) and have pretty steady weight of 51kg or so...
I just don't understand how someone as active as the OP can get by on so little cals and not be either knackered or constantly starving.
Doesn't make any sense.
03/06/2011 at 22:34
hey K9 - hows the knees???
meface    pirate
03/06/2011 at 22:39

Mmmmm....... how boring would we like this to get.................. There are numerous pieces of stuff I may be able to chuck in.

Me,,,ermmm 95kg (which is v.light for me). My RMR (resting Metabolic Rate) is somewhere around 2200kcal per day. With daily life something close to 3000kcal per day. With exercise I can get through quite a few more. Like a whole pack of chocolate digestives for instance.

At 1800kcal per day my weight plumets by a about a stone per month. I sometimes calorie count and track all of these things. Hence I beleive my RMR is 2200kcal rather than the predicted 2000kcal. I am big boned (according to a bone density scan) and they are dense as well. I carry quite a bit of muscle mass as well which burns calories.Either that or I burn a very large number of calories when exercising (I estimate running at about 1000kcal/hour)

So a few things to think about:

  • Large/dense bones take maintenance and burn calories
  • Maintaining fat doesn't burn calories (or very few)
  • Maintaining muscle does burn calories

 The following are three different methods for calculating calorie requirements where the latter two use leand body mass

  • Harris Benedict Equation
  • Katch-McArdle
  • Cunningham 

So why such a low BMR, or an exceptionally efficient exercise burn rate?

Your body could have a genetic low calorie requirement. Your body could be in starvation and burning very few calories - potentially caused by long term dieting at below your RMR.

You could be exceptionally fit but not working out that hard or just not working out that hard period. Walking for an hour uses a lot less than running hard for an hour. I am not saying you are or you aren't working out hard - you just said you trained for an hour or two. But you would need to be bloody efficient.

However even low levels of exercise (walking) will burn 250kcal per hour so two hours would be 500kcal. Ths leaves only 1500kcal to run the rest of your body on (based on 2000kcal). At this point I would be suprised if your body is keeping itself in tip top condition and would be surprised if it was willing to put on any muslce mass.

Is this an issue yes/no/maybe.

Can I increase my bodies RMR - probably

The calorie in/calorie out calculation is pretty much understood. However the guff you here about what you eat, when you it is not quite guff. It is true that if you eat more than you burn you gain weight. However eating regularly and healthily will help boost metabolic rate.

If you have been in starvation mode for some time then every time you a little bit too much your body willbe desparate to storeit as fat (quick to put on)ready for the next starve. It will do this ahead of  boosting metabolic rate and going back to normal maintainance. You need to provide your body enough fuel on a regular basis for a long period of time and convince your body their isn't a shortage anymore. Don't put weight on just fuel it carefully and regularly.

Hope this helps the discussion.


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