There are many different types of environmental impact to consider in your food choices. Imagine you are trying to be a responsible consumer.
Start with your shopping habits. Walking, bicycling, or taking public transit to a store lowers the environmental impact of shopping by comparison with taking a car.
First, you might think about the social cost of food. Are you buying directly from local small farmers or stores that source their food from small farms, or are you supporting big agribusiness? Are you buying food from producers who treat their workers well or ones which exploit their workers, paying starvation wages and having bad working conditions? Also, the less distance food travels the lower the carbon footprint.
Next, look at packaging. Bulk bins, loose fruits and vegetables, and recyclable packages have a lower environmental cost and lots of unneeded packaging that just gets thrown away. Make sure to use your own reusable shopping bags to reduce environmental cost.
In general, animal products, especially meat, have a larger environmental footprint than plant products, and organic food a lower footprint than conventional.