Background & Aim: Frailty is a syndrome characterised by multisystem physiological dysfunction, making older adults vulnerable to stressors. Frailty is often considered as a wasting disorder however there is increasing evidence that many overweight and obese people are also frail. The broad aim of the thesis was to explore whether anthropometric indicators of adiposity and obesity are linked with an increased susceptibility to frailty in middle aged and older European men.Methods: 3,369 men aged 40-79 years were recruited from population registers in eight European centres for participation in the European Male Ageing Study (EMAS) a prospective study of male ageing. Subjects were invited by letter to attend for an interviewer-assisted questionnaire, functional assessments and anthropometric measurements including height (m), weight (Kg), waist (cm) and hip circumference (cm), from which body mass index (BMI) (Kg/m2), and waist hip ratio (WHR) were calculated. Subjects were assessed again after a median of 4.5 years, using the same study instruments. They were asked also about occurrence of falls in the past year. Frailty was assessed using adaptations (because of availability of data) of two established methods, the frailty phenotype (FP) and the Frail Scale (FS), both comprising 5 domains, and also a Frailty Index (FI) a ratio based on observed over a range of potential deficits. Incident frailty was defined as the new occurrence of frailty in those who were not frail at baseline.Results: 3369 men, mean age 60yrs contributed data to this analysis. Using data from the study the prevalence of frailty at baseline was 2.6% using the FP method and 2.7% using the FS and the mean Frailty Index was 0.13 (IQR=0.05-0.18). The prevalence of frailty increased with age. Those who were frail, using either definition had a significantly increased waist circumference (WC) and also WHR. The FI was higher and also correlated with these anthropometric measures. During follow-up there were 193 deaths. Compared to those who were not frail at baseline those who were frail had an increased risk of mortality and also were more likely to experience falls. Of those who were not frail at baseline and who completed the follow-up assessments the incidence of frailty ranged from 2.1% to 3.5% depending on the definition. Mean Frailty Index increased from 0.12 to 0.13, in men who returned at follow-up. An increase in baseline adiposity measures WC & WHR was significantly associated with frailty incidence, at follow-up using both (FP & FS) models, while there was no association with BMI and % body fat. An increase in all baseline adiposity measure was significantly associated with frailty incidence defined by the FI and also a change in the Frailty Index. Conclusion: Frailty models adapted to EMAS predicted adverse outcomes. Obesity was associated with frailty and predicted frailty incidence at follow-up. Interventions to combat obesity in the elderly may help in preventing and reducing the occurrence of frailty.