%0 Journal Article %T Is There a Reversal in the Effect of Obesity on Mortality in Old Age? %A Jiska Cohen-Mansfield %A Rotem Perach %J Journal of Aging Research %D 2011 %I Hindawi Publishing Corporation %R 10.4061/2011/765071 %X Studies of obesity and its relationship with mortality risk in older persons have yielded conflicting results. We aimed to examine the age-related associations between obesity and mortality in older persons. Data were drawn from the Cross-Sectional and Longitudinal Aging Study (CALAS), a national survey of a random sample of older Jewish persons in Israel conducted during 1989每1992. Analyses included 1369 self-respondent participants aged 75每94 from the Cross-Sectional and Longitudinal Aging Study (CALAS). Mortality data at 20-year followup were recorded from the Israeli National Population Registry. Obesity was significantly predictive of higher mortality for persons aged 75每84, but from age 85 onwards, obesity had a protective effect on mortality albeit at a nonsignificant level. Being underweight was consistently predictive of mortality. Findings suggest that the common emphasis on avoiding obesity may not apply to those advancing towards old-old age, at least as far as mortality is concerned. 1. Introduction Increased obesity rates comprise a major public health concern over the world [1, 2]. While obesity was associated with increased mortality risk for young and middle-aged adults [3, 4], studies of older persons have yielded conflicting results. Some indicate higher mortality rates for obese older persons [4每6], while others found no such associations [7每9] or evidence for a reversed relationship, that is, linking decreased mortality with higher Body Mass Index (BMI) values [9每13]. Studies of the relationship between obesity and mortality among older persons suggest the impact of obesity varies according to age. In a study of persons aged 44每101 with 23 years of followup, obesity increased mortality only among persons under 75 years of age [5]. Similarly, a study of adults aged 30 and over with a 12-year followup found higher mortality rates for obese younger persons, but not for those aged 75 and over [14]. In line with that, higher BMI was associated with lower mortality among persons aged 70每88 [9], among older persons aged 70 and older [12], and among persons aged 75每89 [10]. This paper addresses the following question: what are the age-related associations between obesity and mortality in older persons? Accordingly, we examine the impact of obesity on mortality in persons who survived to old-old age, that is, persons over 75 years of age. 2. Methods and Procedures 2.1. Participants and Procedure The sample was part of the Cross-Sectional and Longitudinal Aging Study (CALAS). The CALAS conducted a multidimensional assessment of a random %U http://www.hindawi.com/journals/jar/2011/765071/