2.1. Life Cycle Assessment

systematically estimate the complete environmental consequences and analyze all the energetic and material exchanges occurring in the environment, and

quantify the various emissions into air, water and land in every life cycle phase, and

detect any significant change in the environmental effects in an objective way, and

estimate the effects of material consumptions and environmental emissions on the health of human beings and on the ecosystem as related to food production. The analysis was performed using the Life Cycle Assessment (LCA), an objective procedure for the evaluation of the energy and environmental impacts of a process or activity. More relevant results stem from the application of the LCA methodology to the total environmental impact of a complete dietary pattern, rather than from its partial application to single steps or single impact subcategories of a production process, or to specific food items. The LCA approach allows to:

Usually, it is carried out through the identification of the energy and raw material consumption and the release of waste into the environment: the assessment includes the whole life cycle of a real process or a real activity, from the extraction and processing of raw materials to the production, transportation, distribution, use, reuse and recycling, and final disposal.

Since the aim of our study was to evaluate the pure food-related impacts, focusing on theoretical diets and keeping other variables fixed ( i.e. , not to compare locally-produced, low-impact foods versus imported, high-impact foods), we did not consider any difference related to geographical zone or transportation; the import-export food fluxes have not been considered, nor related emissions during cooking and storing in the household/in restaurants have been taken into account. The system boundaries included the following steps in the process chain: agricultural production, processing and packaging.

According to ISO 14040 standards for LCA [ 22 ], four phases have been performed: 1, Goal and Scoping; 2, Life Cycle Inventory; 3, Life Cycle Impact Assessment, LCIA; 4, Life Cycle Interpretation.

2.1.1. Goal and Scoping The goal of the study was to compare the environmental impact of the OMN, LOV and VEG dietary patterns proposed in the USDA DG for Americans [ 20 ]. We took into account only food produced by intensive, non-organic farming, both because this is, and is likely to remain, the most widespread method, and because previous research had already shown that the production method (non-organic or organic) [ 16 ] and transportation [ 23 ] have much less influence on the overall environmental impact compared to the source (animal or plant) of the food. The software we selected to carry out the Inventory Analysis and the Impact Assessment was SimaPro 7.3.3 [ 24 ].

2.1.2. Life Cycle Inventory In this phase, which is the core of any LCA, all data were collected, and a model representing the whole life cycle of the products, processes and activities was prepared. In some cases, as stated in the USDA DG, it was necessary to subsume individual foods into overall categories, in order to compare new results with existing databases or previous literature which, sometimes, presented simplified data for “fruit”, “vegetables” and “cheese”. 18,19,25,26,27,28,29,30,31,32,33,34,35,36, Input/output data on processes in the food sector have been collected from a variety of sources. Data on production in agriculture and fishery have been determined by a “top-down” approach, where statistical data on a national level have been broken down to represent specific processes. Specific data collection was performed from textbooks/scientific papers describing specific case-studies [ 16 37 ].

2.1.3. Life Cycle Impact Assessment (LCIA) In the LCIA phase, the collected data were used to evaluate the various environmental impacts, and to quantify the impact of each single process on the overall damage. selection of impact categories (environmental effects) and of the environmental indicators representing them;

attribution of the results of inventory analysis to the selected impact categories (classification), according to the effects they exert or may exert on the environment. The elements necessary to this assessment are: The software assigns to each component of the diet a “weight”, i.e. , an a-dimensional value, which represents the intensity of the effect that each component exerts on the environment. The “total weight” of each diet, called single score, is expressed in points ( Pt ), the unit of measure used by the software to assign a numeric value to the overall environmental impact of the diet. The higher the “score” in Pt , the higher the damage to the environment. In order to obtain a complete analysis, to facilitate comparison with data from other studies, and to minimize bias, the assessment phase has been conducted using all the indicators made available by the SimaPro software. Ecoindicator99 damages to human health (substances which have a negative impact on respiration, organic and inorganic compounds, carcinogenesis, climate change and ozone, ionizing radiations);

damages to ecosystems quality (ecotoxicity, acidification and eutrophication);

damages to resources (use of primary resources—land and water—and of fuel). A damage-oriented indicator that analyses the following impacts, which can be further categorized according to three large damage categories: Ecopoint x , SO x , NH 3 , CO 2 , Metals, COD, DUST PM 10 , etc. ). The Swiss Ecopoints 1997 (environmental scarcity) is an update of the 1990 method, based on actual pollution and critical targets, derived from the Swiss policy for Environment. It comes in 3 versions, with identical evaluation and indicator values but different in the normalization factor; the version number 2 is used in SimaPro [ An indicator designed to evaluate the impacts due to the release of chemicals into the environment (NO, SO, NH, CO, Metals, COD, DUST PM). The Swiss Ecopoints 1997 (environmental scarcity) is an update of the 1990 method, based on actual pollution and critical targets, derived from the Swiss policy for Environment. It comes in 3 versions, with identical evaluation and indicator values but different in the normalization factor; the version number 2 is used in SimaPro [ 38 39 ]. EDIP A method adapted for LCA food database projects, representing the most used and widespread indicator to evaluate different forms of toxicity (global warming, acidification, eutrophication, ecotoxicity, human toxicity). The LCIA was carried out three times, once for each indicator. LCA experts assume a general uncertainty of 10% to 20% in the results [ 40 ].