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
2.5. Statistical analysis
The relations between diet-related GHGE and other dietary variables (energy, weight, MAR, MER, DE,
food group intakes) were tested using both simple and partial (adjustment for age, gender and energy intakes)
Pearson’s correlation coefficients. The food group intakes and the diet-related GHGE were estimated among
the 4 nutritional classes. Then, comparisons of means among the 4 classes and tests for linear trends were
performed using regression analysis for sample survey data for men and women separately. In additional
analyses, diet-related GHGE were adjusted for energy intake. An alpha-level of 0.05 was used to determine
statistical significance. Statistical analyses were performed using SAS software version 9.2 (SAS institute,
Cary, NC).
3. Results
3.1. Correlation between diet-related GHGE and nutritional quality indicators
In simple regression analyses, the MAR (R = 0.67, p< 0.0001), the MER (R = 0.80, p< 0.0001), dietary
ED (R = 0.34, p< 0.0001) and diet-related GHGE (R = 0.79, p< 0.0001) were each positively and significantly
correlated with energy intakes. As expected, after energy adjustment, dietary ED was positively correlated
with MER and negatively with MAR; higher MAR scores were associated with lower MER scores.
After energy-adjustment, diet-related GHGE was positively correlated with MAR and negatively with dietary
ED, but no correlation was observed with the MER (data not shown).
3.2. GHGE of food groups and effect of their consumption on total diet-related GHGE
Whatever the calculation basis (per 100g or per 100 kcal of food consumed) the highest GHGE was recorded
for the Meat, Fish, poultry and eggs (MFPE) group and the lowest for starchy foods group (Figure 1).
Among the MFPE group, meat had the highest GHGE, which was more than 10 times higher, on a weight
basis, than that of fruit and vegetables (1387g vs. 121g CO2e/100g respectively, data not shown). The second
lowest GHGE value (after that of starchy foods), was observed for fruit and vegetables when calculated on a
weight basis, but for sweets and salted snacks when calculated on a calorie basis. When expressed per 100
kcal, the GHGE of fruit and vegetables was similar to that of dairy products.
Figure 1. Greenhouse gas emissions (GHGE) related to the consumption of each food group, expressed per
100g and per 100kcal of foods as consumed by adults (n=1918) participating in the INCA2 survey. Values
are means. Bars represent the 95% confidence interval.
After adjustment for age, sex and energy intake, a higher consumption of sweets and salted snacks, and of
mixed dishes and starchy foods was associated with a lower diet-related GHGE (Figure 2). In contrast, increasing
the intake of the other food groups, including that of fruit and vegetables, increased diet-related
GHGE. The strongest positive association was seen for the MFPE group (and within that group, for the meat
category, data not shown).
124
GHGE, g CO 2 eq./d
1000
900
800
700
600
500
400
300
200
100
0
85
46
121
306
Starchy foods Fruit and
vegetables
GHGE/100 g GHGE/100 kcal
202
153
218
95
436
Mixed dishes Sweets and Dairy products Fat Meat, fish,
salted snacks
poultry, eggs
297
859
145
934
505