The global food system is estimated to contribute to 30% of total Greenhouse gas emissions. The issue of how to incentivize consumers modifying their diet is crucial. We consider here food taxation scenarios aiming at reducing environmental emissions through different CO2tax options. Data proceed from Kantar purchases for food-at-home of French households on the 1998-2010 period. Our main result is that a uniform tax scenario, set at a 20% rate, induces a greater emissions reduction than a proportional to emissions tax scenario, based on a 50€/tCO2 carbon cost. Therefore a 20% tax scenario on targeted foods could result in a better incentive to consumer choices in an environmental perspective. Moreover, the implementation of a VAT increase is probably easier than any other tax regulation.