Abstract 21291: Seasonal Fluctuation in Weight is not Associated with Weight Gain
Introduction: Cycles of gain and loss of weight (“weight cycling”) have been associated with later weight gain but results are not consistent. Many physiological measures vary seasonally, yet data for seasonal weight variation is limited. It is not known whether seasonal fluctuation in weight is associated with weight gain.
Hypothesis: Weight will vary seasonally but seasonal weight fluctuation will not be associated with longitudinal weight change.
Methods: Subjects were 69,337 (3,922 female, 5,488 minority race/ethnicity) veterans aged 18 to 100 years enrolled at the Phoenix VA Health Care System with serial measured weights recorded at outpatient visits between January 1999 and February 2006. Random effects mixed models were fitted to sequential weights for 14 age cohorts (18-25, 86-100, and 5-year intervals between 26 and 85). Models included fixed effects for sex, season, and time. Linear and quadratic time allowed for nonlinear change.
Results: Findings for men and women were generally similar and are presented for all. Seasonal weight fluctuation was identified in all 14 cohorts (p<0.005 for all). The magnitude of seasonal weight fluctuation was relatively similar for all 14 age cohorts, ranging from a low of 1.2+0.3 lb to a high of 1.61+0.08 lb. Among the cohorts, the maximum weight was observed in the 24 day period between December 28 and January 20. The magnitude of seasonal weight fluctuation was 1.36+0.23, 1.47+0.07, and 1.40+0.17 lb in 26-30 year olds with the greatest 7-year weight gain (18.1+2.6 lb), 61-65 year olds who were weight stable, and 86 to 100 year olds with the largest weight loss (11.4+1.0 lb), respectively. For these cohorts, the respective times of peak weight were January 16, January 16, and January 20 with corresponding minima 6 months later. Other analyses within age cohorts suggested that the magnitude of seasonal weight fluctuation was not related to BMI or 7-year weight change.
Conclusions: Seasonal weight fluctuation does not seem to be associated with either weight loss or weight gain. Seasonal weight fluctuation may both account in part for seasonal fluctuation in serum lipids and other physiological measures and provide a window of opportunity in which weight loss efforts might be more successful.
- © 2010 by American Heart Association, Inc.