PurposeThe purpose of this research is to measure changes in food habits of first‐generation immigrants in Montreal (Quebec, Canada), as well as their self‐declared state of health and physical activity level. A subset of the sample was found to be in a state of food insecurity (FI).Design/methodology/approachA supervised questionnaire was administered to 506 adult allophone immigrants attending French‐language courses, autumn 2011. A FI indicator was developed and applied to this sample. The authors discuss the concept of FI and issues about measurements of FI.FindingsIn total, 10 per cent of the sample was found to suffer from FI, which has a negative impact on fruit, vegetables, dairy product, fish and red meat consumption, and diet quality in general. FI shows a positive correlation with changes in state of health and lifestyle and the development of chronic disease such as type 2 diabetes and coronary heart disease. Results also show that certain groups are more at risk, that FI prevalence decreases with the years of residence and that FI is a deep source of anxiety.Originality/valueFI should be monitored in a more systematic manner in recent immigrant populations and be specifically addressed in immigrant integration policies. The authors also stress that problems occurring because of FI are rooted in the incapacity and the failure of the social programs to protect very low income families from harmful consequences of poverty.