PurposeThe purpose of this study is to determine the antecedents of obesity among the younger generation of Indians (Generation Y) from a psychological and lifestyle consumer perspective. The study also investigates the moderating role of demography on the body mass index (BMI) of Indian youths.Design/methodology/approachThe study initially develops a conceptual model, stemming from an extensive theoretical research, and subsequently validates this using structural equation modeling (SEM) technique with a sample size of 1,242 Indian youths.FindingsThe study concludes that consumers' food habits (FH) and physical activity (PA) positively impact consumers' physical health (PH), which influences their BMI levels (BLs). Anxiety (AX), depression (DE), stress (ST), peer pressure (PP) and work pressure (WP) impact individuals' mental health (MH), which also influences their BLs. Finally, there is a significant moderating impact of demographic factors, such as age (AG), gender (GE) and income levels (ILs) on the relationship between individuals' physical and MH and individuals' BLs.Research limitations/implicationsThis study proposes a new model which highlights the issue of youth consumer obesity from the psychological and lifestyle perspectives. The model is effective as it has a high explanative power of 73%. The study investigates consumer obesity from emerging market like India perspective, but the study does not examine consumer food consumption behavior and obesity from developed market perspective.Practical implicationsYouth obesity could be considered a global pandemic, and obesity rates among the Indian youth are also increasing. This study provides valuable inputs and understanding of consumer markets to policy makers, consumer protection institutions, organizations related to the food and beverage industry, healthcare workers and consumers themselves regarding the antecedents of youth obesity (BL) in developing and emerging markets.Originality/valueThe study adds value to the body of literature related to consumer obesity, FH, consumer psychology and lifestyle through findings that are new in terms of findings' specificity, contextual focus and explication. Moreover, the study extends the cognitive theory of DE and the theory of planned behavior (TPB). The research effectively offers significant theoretical and practicable market knowledge to both scholars and marketing practitioners, as well as policy makers and institutions dealing with youth obesity, particularly in emerging markets.