![]() |
|
|
The Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC 27516
3To whom correspondence should be addressed. E-mail: jstookey{at}email.unc.edu.
Studies describing patterns of long-term change in body composition
are lacking. Using longitudinal data on 608 healthy, nonobese Chinese
(aged 5070 y) from the 1993 and 1997 China Health and Nutrition
Surveys, this article describes the prevalence, sociodemographic and
lifestyle correlates of patterns of long-term change in midarm
muscle area (MAMA) and body fat (waist circumference). All patterns of
change (loss, maintenance [
< 1.3 cm2], or gain
of MAMA with concurrent loss, maintenance [
< 2
cm2] or gain of body fat), were observed for this sample.
After controlling for sex, baseline age, urban residence, height,
weight, income, MAMA, waist circumference, smoking status, activity
level, mean daily energy and protein intakes (from three 24-h recalls),
and change in height, it was determined that subjects who lost both arm
muscle and body fat were distinguished from subjects who lost arm
muscle but gained body fat by lower income and energy intake at
baseline. Although protein intakes at baseline did not differ between
the groups that lost arm muscle, protein intakes were significantly
higher for subjects who gained both muscle and fat. Patterns of change
involving gains in arm muscle were associated with increased protein
intake, urban residence, as well as moderate or heavy levels of
physical activity at baseline. Variation in protein intake, physical
activity, and urban residence also differentiated between the groups
that gained fat. Patterns of age-related change in body composition
appear associated with modifiable variables, including income, urban
residence, activity and protein and energy intake.
KEY WORDS: body composition sarcopenia diet activity aging