Energy and protein requirements

[Guest guest]

There have been some recent discussions about protein restriction.

The following report has a section dealing with this topic.

Tony

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Energy and protein requirements.

A report from the World Health Organization, the Food and Agriculture

Organization of the United Nations, and the United Nations University

http://www.fao.org/DOCREP/003/AA040E/AA040E00.htm#TOC

The section 5.2 " Adaptation to low protein intakes " :

http://www.fao.org/DOCREP/003/AA040E/AA040E05.htm#ch5.2

When an adult man is transferred from a higher than customary N intake

to one that is close to the physiological minimum, e.g., from 14 to 4

g N per day, a level of excretion close to a new steady state is

reached in about 7 days (14), and over this period there is a

cumulative N loss equivalent to about 1.5% of total body N. In similar

studies on children the new steady state was reached more rapidly,

with a total loss estimated at 1% of body N (15). In experimental

animals the losses on passing from a customary to a lower protein

intake are relatively greater. From such experiments it is known that

initially most of the N is lost preferentially from the liver and gut

(16, 17). Later, because of the recycling discussed above, it is the N

content of muscle and skin that is mainly reduced (18).

Nigerian farmers could achieve [nitrogen] balance with an intake that

was apparently inadequate for North American men, several short-term

balances that have been carried out since 1971 reveal no striking

differences in the estimates of maintenance requirement in relation to

body cell mass obtained in studies of well-nourished subjects in

different countries. However, the question of long-term adaptation

cannot be answered definitively without further research.

Given the evidence currently available, it must be concluded that

there is probably only limited scope for metabolic adaptation to N

intakes below the physiological minimum for N balance found in

subjects with " normal " intakes. The important question that remains is

whether the degree of adaptation that does occur, consistent with the

maintenance of nitrogen equilibrium, represents a metabolic adjustment

without functional significance, or whether it is detrimental to

health and long-term survival.

[Guest guest]

Hi Tony:

Funny isn't it, that they were unable to consider the possibility

that restricted protein might be associated with benefits! Probably

it isn't, but that wording discloses a clear bias.

'More is better' is ingrained.

Rodney.

> The important question that remains is whether the degree of

> adaptation that does occur, consistent with the maintenance of

> nitrogen equilibrium, represents a metabolic adjustment without

> functional significance, or whether it is detrimental to health and

> long-term survival.

[Guest guest]

Hi Tony:

Funny isn't it, that they were unable to consider the possibility

that restricted protein might be associated with benefits! Probably

it isn't, but that wording discloses a clear bias.

'More is better' is ingrained.

Rodney.

> The important question that remains is whether the degree of

> adaptation that does occur, consistent with the maintenance of

> nitrogen equilibrium, represents a metabolic adjustment without

> functional significance, or whether it is detrimental to health and

> long-term survival.