The development of dietary preferences of adolescents involves a complex interplay of individual behaviours and environmental factors. Interpersonal factors-such as peer influences and unpleasant school experiences-and institutional factors-such as school rules and policies-are closely associated with unhealthy eating of adolescents. Family support and guidance are also crucial in influencing adolescents' eating habits. However, the low social status, low educational levels, and low household incomes of disadvantaged parents can markedly prevent their children from establishing healthy eating habits. Therefore, adolescents from low-income families are more likely to engage in unhealthy dietary behaviours and hence to be more susceptible to diet-related health problems. However, few studies have addressed the difficulties associated with inculcating healthy eating habits among adolescents from low-income families. Therefore, to investigate the barriers to adopting healthy eating habits, this study adopted a qualitative research approach and conducted five focus-group semistructured interviews with 30 junior- and senior-form students of a secondary school in Hong Kong, all of whom were from low-income families. The results revealed skipping meals because of poverty, following irregular meal patterns on school holidays, receiving poor guidance from family and peers, perceiving healthy eating as expensive and unappealing, and geographical inaccessibility to healthy food all prevented these students from healthy eating. These mutually reinforcing factors were interlocking with the economic strain that was experienced by the participants and their families. In particular, the stereotype of "healthful food is expensive" was strong. Therefore, we suggest students from low-income families should be enabled to understand that healthy eating is not necessarily expensive. The participants' stereotypes about healthy food was handed down by their parents. Such stereotypes, together with the low health literacy, influence the food preparation habits of the parents. Therefore, parents should be made to aware that healthful food can also be affordable.