Nutritional Equilibrium

[Guest guest]

wrote an insightful message about CR and the process of

achieving nutritional equilibrium. I have tried to crunch some

numbers in a spreadsheet in order to get a better perspective of what

is in store for us.

>>>===Message 15853

From: " " <crjohnr@b...>

Date: Thu Oct 28, 2004 1:05 pm

Subject: RE: Osteoporosis in CRON

.... If we accept as a given that CR involves energy restriction below

some poorly defined prior equilibrium point ( " set-point " ), a sustained

energy deficit will consume energy stores typically adipose. CR

involving significant " R " and of adequate duration will not only

deplete such energy stores, but at some point also consume LBM. We are

aware of cases where improper dieting led to dangerous loss of heart

muscle, even properly executed there is expectation that adult onset

of significant CR will result in remodeling of LBM.

.... I would be surprised if low, but adequate %BF is not one such

mechanism. While it also appears obvious that adequate raw materials

must be ingested to support LBM at whatever equilibrium level after

remodeling. If we don't support maintenance and we can't remodel

lower, we will suffer systemic failures in bone integrity, organ

function, or in extremis life. I recall one CR'd individual who

reports losing inches of height.

JR 55YO/22BMI/10%BF

>>>

In Message 14169 I posted equations to predict Lean Mass gain and

loss. The equations are important to bodybuilders because they want

to maximize muscle growth and decrease the percentage of body fat.

The equations are applicable to people practicing CR because they

provide some perspective on the weight-loss process. Notice that the

formula requires weights in Kg). In my spreadsheet I converted the

formulas to pounds.

Lean Mass Gain/Weight Gain = 10.4/(10.4 + initial fat weight (kg))

Lean Mass Loss/Weight Loss = 10.4/(10.4 + initial fat weight (kg))

If your initial weight is 140 lb, and you lose ten pounds, the amount

of lean body mass that you lose increases as your percentage of body

fat decreases.

At 15% Body Fat, over half of the weight that you lose is lean body

mass (~52%).

At 10% Body Fat, 62% of the weight that you lose is LBM.

%BF . . . . lb LBM loss (%)

30 . . . . . 3.53 (35.3%)

25 . . . . . 3.95 (39.5%)

20 . . . . . 4.50 (45.0%)

15 . . . . . 5.21 (52.1%)

10 . . . . . 6.20 (62.0%)

5 . . . . . 7.66 (76.6%)

When I compared these percentages with my own losses in body weight

and %BF calculated by the Navy method, the results were within a few

percent of the actual numbers.

It is beneficial to know that once you get down to 15 percent

body fat, any further weight losses will start to affect your muscles,

although I recognize that not all lean body mass is muscle.

Seniors who exercise build muscle and strength that enable them to

live more independent lives. But wouldn't it be better to conserve

the muscles that we have by not dieting too agressively?

Tony

http://nihseniorhealth.gov/exercise/benefitsofexercise/03.html

Transcript: " Why Older Adults Should Exercise "

J. Hodes, M.D.

Director, National Institute on Aging:

It's much more than okay for older people to exercise. And

importantly, that is a conviction that is based not just on intuition

but as a result of a good deal of research over the past years. It was

judged that exercise was too dangerous, too vigorous and that older

people, because of frailty, were more likely to be injured or damaged

by exercise. However, a number of well-conducted, controlled studies

have shown that a variety of exercises are not only safe for older

people but have enormous advantage. This includes aerobic exercise

that is good for conditioning of heart and lungs as well as rather

vigorous weight training, (Hodes does bicep curls) which has shown the

ability in people in their sixties, seventies, eighties, and even

nineties, to significantly increase muscle mass, most importantly,

muscle strength, and most importantly of all, to translate that

increase in strength into the ability to carry out functions of daily

living; to climb stairs, to shop, to carry packages. Things that are

important to maintaining independence and health throughout the

lifespan.