drip-feeding protein along with glucose

12.5: news.health/hormonics/drip-feeding protein along with glucose:
. the addition of essential amino acids to the low-calorie diet
restored egg-laying capacity; but, it also reduced lifespan in the flies.
. adding just the essential amino acid methionine
restored egg-laying without reducing lifespan .
Previously, other researchers had found that reducing methionine
in a normal diet could extend lifespan.
ÒThere's a sort of asymmetry in the relationshipÓ
between methionine levels and calorie counts, Piper says.
ÒWhen food is low, lots of methionine is OK.
When food is high, reducing methionine can lengthen lifespan.Ó
But other researchers who study aging and calorie restriction
aren't so sure that balancing amino acids will have the same effect
in humans and other mammals.
. it really is calorie content that matters for lengthening lifespan .
. previous findings about human response to protein
was that cutting protein could reduce levels of IGF-1, involved in aging
(SN: 10/25/08, p. 17).
. it would be a nearly impossible to experimentally find
the correct amino acid balance for humans,
but human cell investigations are hopeful .