ObjectivesIndia, a major contributor to the global diabetes burden, is witnessing a simultaneous epidemic of obesity leading to rise in diabesity. Diabesity, the coexistence of diabetes and obesity in an individual, has emerged as a risk factor for other morbidities and hence, multimorbidity. Although diabesity has long been recognised, still, there is a poor understanding of its social determinants in India, necessary for its control. We aimed to estimate and compare the prevalence and identify social determinants of obesity, diabetes and diabesity; explore their association with other selected non-communicable diseases (NCDs) multimorbidity; and assess its outcomes among adults aged ≥45 years.Design and settingWe undertook an observational analyses employing nationally representative data from Longitudinal Ageing Study in India, 2017–2018.ParticipantsThis study was conducted among n=59 073 respondents.Outcome measuresDescriptive analysis was conducted among n=59 073 respondents to determine prevalence of diabetes, obesity and diabesity. The social determinants were assessed using multinomial regression, reported as adjusted relative risk ratio (RRR). A multiple correspondence analysis generated life satisfaction.ResultsThe prevalence of obesity, diabetes, and diabesity was 21.2%, 6%, and 5.8%, respectively. We identified women (RRR: 2.16 (1.72 to 2.71)), urban residents (RRR: 3.73 (3.07 to 4.54)) and affluent groups (RRR: 3.60 (2.46 to 4.58)) had a higher likelihood of having diabesity. The association with various NCDs showed multimorbidity to be akin to the diabesity group. We observed inferior life satisfaction and significantly higher healthcare utilisation among participants with diabesity as compared with other two groups.ConclusionIncreased obesity prevalence has led to the rise in diabesity in India. Additionally, the level of multimorbidity in this group cannot be overlooked. Rather than focusing on individual conditions, an in toto approach to multimorbidity is warranted.