The environmental impact of food is a major concern for climate change. This paper estimates the CO2 emissions due to food purchases of French households and analyses the disparities between income classes. To combine environment with health concerns, we consider as well the caloric content of foods and normalize CO2 emissions on a daily 2000kcalories basis. Data on French food purchases come from Kantar 1998-2010. Using Life-Cycle-Analysis from Greenext, we obtain CO2equivalent emissions for different food groups. Then we adjust levels of emissions by linear regression on income and age. We find that CO2 emissions of food purchases amount to 3.9kg/day/household. Lowest-income households emit more CO2 compared to richest households (+14.7%), but less on an adjusted 2000kcal basis (-9.6%). In a public policy perspective, richer households should be the first target of diet change since their consumption favours higher CO2 emitting food groups than lower-income households, at caloric level constant.