Energy and carbon footprints of food: Investigating the effect of cooking

Abstract

Energy and carbon footprints of foods are of much concern, since food systems account for nearly one third of energy use and Greenhouse Gas (GHG) emissions worldwide. Due to the complexity of mass variations in food processing and the diversity of appliances used in household cooking, most studies on energy and carbon footprints were performed from cradle to farm gate or wholesale stages. However, life cycle studies considering food preparation are important to assess environmental impacts related to both consumer practices and food characteristics. In the present work, we performed an experimental study that involved cooking of 18 foods consumed in Argentina; we report the energy consumption, GHG emissions and mass changes associated with the process. We also defined a nutritional footprint indicator, which allowed us to obtain the energy use and GHG emissions per unit of nutrient content instead of per unit of weight (e.g. per kg of food). We studied the cases of beef, wheat-based bread and soybeans, which represent the three analyzed food groups, to assess the impact of cooking on the cradle-to-table energy and carbon footprint. Our results showed that the relative impact of including the cooking stage in the energy and carbon footprints depends on the analyzed food item, with the impact being more important for plant-based than for meat products. Thus, a reduction in the footprint gap between plant-based and animal-based foods was found.