LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

PLENARY SESSION 1: FOOD 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
and beverages, including water) were listed in a survey-associated food database giving the nutritional composition
of each food item. Total diet weight, total energy intakes, intake of food groups and nutrient intakes
were calculated on a daily basis for each participant, based on the list of foods and beverages he/she recorded,
and the energy and nutrient content of the items consumed.
2.2. Three indicators of nutritional quality
The Mean Adequacy Ratio (MAR), the Mean Excess Ratio (MER) and the dietary Energy Density (ED)
were used as nutritional quality indicators and were estimated without taking into account the nutrients from
alcoholic beverages.
The MAR was used as an indicator of good nutritional quality, as it has been repeatedly shown to be positively
associated with other indices of dietary quality (Cox et al., 1997;Dubois et al., 2000;Krebs-Smith et
al., 1987;Torheim et al., 2004) and with health indicators (Ferland and O'Brien, 2003;Keller et al., 1997). In
the present study, the MAR was calculated for the diet of each individual, as the mean percentage of French
Recommended Dietary Allowance (Martin, 2001) for 20 key nutrients (namely proteins, fibre, retinol-eq,
thiamin, riboflavin, niacin, vitamin B6, folates, vitamin B12, ascorbic acid, vitamin E, vitamin D, calcium,
potassium, iron, magnesium, zinc, copper, iodine and selenium).
We developed the MER by analogy with the MAR, and used it as an indicator of bad nutritional quality.
The MER was calculated for each diet as the mean daily percent of maximal recommended values (MRV)
for three harmful nutrients, namely saturated fatty acids (SFA), sodium and free sugars. The term "free sugars"
refers to added sugars plus sugars naturally present in honey, syrups and fruit juices (Joint WHO/FAO
expert consultation, 2003).
Dietary ED was used as an indicator of bad nutritional quality because diets with a low energy density
have been shown to have a good overall nutritional quality (Ledikwe et al., 2006;Schroder et al., 2008) and
because decreasing the energy density of the diet is recommended by several public health authorities to
prevent obesity and obesity-associated disease conditions (WHO, ;World Cancer Research Fund International/
Association Institute of Cancer Research, 2007). Dietary ED (in kcal/100g of diet) was calculated by
dividing the energy intake by diet weight of each individual. As proposed by Ledikwe et al., (Ledikwe et al.,
2005), items typically consumed as beverages, such as milk, juices, and soft drinks, were excluded of the
calculation of energy density.
2.3. Four classes of nutritional quality
A method for classifying individuals based on the nutritional quality of their diets was specifically developed
for this study. The three indicators of nutritional quality described above were calculated for each diet.
Individuals were then ranked according to the values taken by each indicator compared to its observed median
in the populations of men and women separately. A class 1 nutritional quality diet was defined as a diet
complying with the three following nutritional objectives: having a MAR above the median, a MER below
the median and a dietary ED below the median. Diets complying with only 2, 1 or 0 of these objectives were
allocated to class 2, class 3 and class 4 nutritional quality, respectively.
2.4. Estimation of diet-related GHGE
As described elsewhere (Supkova et al., 2011;Vieux et al., 2012), the estimation of diet-related GHGE
was based on a selection of 73 widely-consumed food items for which a series of assumptions were made.
We assumed that the selected food items were all obtained through the conventional and most frequent production
and distribution processes in France. The food-related GHGE values covered the stages of agricultural
production, processing, packaging and transportation to retail outlets but the stages that occur after purchase
(transportation from store to home, storage, preparation and cooking at home, management of end-oflife
phases) were not recovered due to a lack of data. Data were expressed as g CO2 equivalent per 100g of
edible portion (g CO2e /100g). As previously described (Vieux et al., 2012), a Monte-Carlo simulation was
run in order to introduce variability of a GHGE food item and a weighting factor was calculated for each
representative food item selected within each category to allow us to estimate the GHGE associated with the
food category.
123