RT Journal
A1 Hankinson AL, Bouchard C, Liu K
T1 PHysical activity and weight gain over 20 years—reply
JF JAMA
JO JAMA
YR 2011
FD April 6
VO 305
IS 13
SP 1297
OP 1298
DO 10.1001/jama.2011.398
UL http://dx.doi.org/10.1001/jama.2011.398
AB 
In Reply: Noting that our study showed that increases in BMI and waist circumference occurred even with habitual high activity over 20 years, Dr Jolley and colleagues ask whether an activity level associated with no increase in BMI or waist circumference, ie, with weight maintenance or weight stability, was found. Since weight varies in free-living adults even when fat stores are relatively constant, weight fluctuation within a reasonable range is still defined as weight stable in the literature.1 Although no consensus exists in establishing this range, previous work in the CARDIA cohort has defined weight maintenance as ±2 BMI units of baseline BMI (calculated as weight in kilograms divided by height in meters squared) or ±5 pounds of baseline weight.1- 2 Young adults maintaining stable BMI had minimal progression of cardiovascular disease risk factors.2