Caloric Intake ~=~ Body Weight

[Guest guest]

Hi folks:

Here is a little exercise: a while back, when justifying the use of

body weight as a measure on CRON level achieved, I made the statement

that weight loss and reduced caloric intake were simply two sides of

the same coin. This is related to the known fact that mice (and the

same will apply to humans) that are subjected to 40% caloric

restriction weigh 50% less than those fed ad lib. This post takes

these points a little further.

Using the -Benedict (H- equation I calculated how many

calories I 'should' be consuming, when sedentary, at various

different body weights, given my height and age. These data show, of

course, that at heavier weights I would burn off more calories than

if I am lighter. At 170 pounds it says I should be burning off 1,912

calories daily. If I were to drop to 140 pounds my sedentary caloric

expenditure, according to H-B, should drop to 1,690. (We have

previously discussed that actual caloric expenditure may vary

considerably from the H-B prediction from one individual to another,

but presumably NOT for variations of caloric expenditure with weight

for a single individual).

What is a little bit interesting is that at 140 pounds, a weight

17.6% less than 170 pounds, my predicted caloric intake is 11.6% less

than it would be at 170 pounds. Now if we turn this around the other

way, one could say that the H-B equation suggests that if my weight

was stable at 170 pounds, and I then reduced my caloric intake by

11.6%, my weight should decline by 17.6% - my weight declining by

MORE than the reduction in caloric intake. This, of course what the

mouse experiments seem to show.

Taking this one small step further, for me between weights of 140

pounds and 170 pounds, for each percentage change in weight my

caloric expenditure changes by almost exactly two-thirds of one

percent. Or alternatively, for each one percent sustained change in

caloric intake my weight should change by almost exactly 1.5%.

Probably at very high levels of restriction this relationship will

change. But all the same it does seem to suggest that, if the H-B

equations are anywhere close to being accurate for weight variations

in a single individual then, even when initiated in adulthood, 40%

restriction, if attempted, would be associated with HUGE loss of

weight.

Previously I had wondered if the 50% weight loss only occurred when

restriction was started long before full growth stature had been

attained. But these 'H-B generated' data suggest not.

Rodney.