Low Body Weight and CR -- Both Help You

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The following study -- by Dr. Walford's best known student,

Dr. Weindruch -- identified the percent contribution

of two different factors that increase longevity:

*** (1) Maintaining a low body weight

*** (2) following a CR diet

The results showed the following:

" The reductions in BW (body weight) appeared to account for

approximately 11% of the effect of CR. " (very bottom, text below)

This hints that if you you are going to pursue a CR diet,

staying on the thin side will gain you an extra 11% beyond

the benefit of simply reducing calories. -- Warren

=======================

International Journal of Obesity (2004) Mar 28(3):357-62, pp 357-362;

Caloric Restriction and Body Weight Independently Affect Longevity

in Wistar Rats.

Wang C, Weindruch R, Fernandez JR, Coffey CS, Patel P, DB.

[1] Section on Statistical Genetics, Department of Biostatistics,

Univ of Alabama at Birmingham, Birmingham, AL, USA

[2] Clinical Nutrition Research Center, University of Alabama at

Birmingham, Birmingham, AL, USA.

OBJECTIVE:: To evaluate the independent effects of caloric

restriction (CR) and body weight (BW) on mortality rate (MR) and

the extent to which BW may mediate the effect of CR on MR. DESIGN

AND SUBJECTS:: Data were from the Biosure Study, a randomized,

controlled, prospective intervention study of diet regimens in

1200 Wistar rats. Animals were followed until they died

spontaneously, were euthanized because of illness, or reached age

30 months. STATISTICAL ANALYSIS:: regression was performed to

evaluate the effects of CR and BW on MR. Bootstrap procedures

were used to test the contribution of BW to the effect of CR on

MR. RESULTS:: CR initiated after age 13 weeks decreased the rate

of subsequent mortality. The MR increased with higher BW in early

adulthood (21 weeks) and this effect persisted even after

adjustment for CR. After adjustment for BW in early adulthood, we

did not find a similar relation between mortality and BW in late

adulthood (105 weeks). Mediation analysis indicated that low BW

associated with CR appeared to mediate some of the mortality-

reducing effects of CR, but CR clearly had effects independent of

BW. The reductions in BW appeared to account for approximately

11% of the effect of CR. CONCLUSION:: CR and BW have independent

effects on MR in Wistar rats. BW may mediate a small part of the

CR effects on MR. International Journal of Obesity (2004) 28, 357-

362. doi:10.1038/sj.ijo.0802518 Published online 13 January 2004

PMID: 14724654 [PubMed - in process]