We included all 7,447 participants (4,282 women and 3,165 men) in the PREDIMED trial. The mean (± SD) of the 14-item score was 8.6±2.0. Mean values (± SD) for the 14-item score were 8.5±2.0 for women and 8.7±2.0 for men. More men than women were at or above 10 points in the 14-item score (). No differences in average age, prevalence of hypertension or prevalence of dyslipidemia were found across categories of adherence to the Mediterranean diet. The prevalence of diabetes and current smoking were lower among participants with higher adherence to the Mediterranean diet, whereas the prevalence of family history of coronary heart disease was higher in participants scoring ≥10. Adherence to the Mediterranean diet was directly associated with physical activity, total energy intake, alcohol consumption, and educational level. Married subjects exhibited a greater adherence to the Mediterranean diet than did subjects in other categories of marital status.
Characteristics of participants by adherence to the Mediterranean diet (14-item score).
For all the three indexes of obesity, we found an apparent inverse association with the 14-item Mediterranean diet score both for women and men in the crude analyses (p<0.001 for all comparisons, with the exception of p
0.001 for BMI among men) (). However, the correlation coefficient was strongest for the WHtR, both among women and men (). Specifically, the inverse correlation coefficient between the 14-point score and WHtR (r
–0.121 for men and women considered together) was greater than the inverse correlation for WC (r
–0.095) or BMI (r
–0.080). This was also true when the non-parametric Spearmańs rho was used (rho
–0.124 for WHtR, rho
–0.097 for WC and rho
–0.092 for BMI). Partial correlations controlling for total energy intake between the 14-point score and adiposity indexes rendered similar results with rpartial
–0.118 for WHtR, –0.101 for WC and –0.084 for BMI.
Means (95% confidence intervals) for Indexes of general obesity and abdominal obesity by adherence to the Mediterranean diet.
The inverse association between the score of adherence to the Mediterranean diet and the three indexes of obesity remained statistically significant in multivariable analyses (). For each 2 additional points in the 14-item Mediterranean diet score, the WHtR was 0.0066 lower (95% CI, –0.0088 to –0.0049) in women and 0.0059 lower (–0.0079 to –0.0038) in men. These estimates did not appreciably change after adjustment for total energy intake obtained from the FFQ.
Multivariable-adjusted differences (95% confidence intervals) in indexes of general obesity and abdominal obesity by adherence to the Mediterranean diet.
We also found an inverse association between adherence to the Mediterranean diet and both general obesity and abdominal obesity. The OR of abdominal obesity (WHtR>0.6) for each 2 additional points in the score, was 0.85 among women (95% CI, 0.79 to 0.92) and 0.84 among men (0.88 to 0.91) in fully-adjusted models ().
Prevalence of obesity and multivariable-adjusted odds ratios (OR, 95% confidence intervals) for abdominal obesity and general obesity by adherence to the Mediterranean diet.
When both men and women were considered together, a monotonic inverse association between the 14-item score and the odds of abdominal obesity (WHtR>0.6) was apparent (). Taking as reference 9 points (OR
1.00), significantly lower odds for abdominal obesity (WHtR>0.6) were found for participants scoring either 10 points (OR 0.83; CI 0.71 to 0.98) or ≥11 points (OR 0.74; 0.62 to 0.87), whereas significantly higher odds were found for those scoring 6–7 points (OR 1.19; 1.02 to 1.40), or ≤5 points (OR 1.51; 1.17 to 1.94).
Multivariable-adjusted odds ratios (OR, 95% confidence intervals) for abdominal obesity (waist-to-height>0.6) by adherence to the Mediterranean diet.
With the exception of one item (butter/cream/margarine), all the odds ratios for the individual items included in the 14-item Mediterranean diet score showed point estimates suggesting inverse associations with the odds of abdominal obesity (). Changes in these point estimates before and after additional adjustments for other potential confounders were small. In any case, the results were not statistically significant for four items: the second of the two items for olive oil consumption (p
0.35), low consumption of red/processed meats (p
0.18), low use of commercial bakery (p
0.10) and preference for poultry instead of red meats (p
0.57). The strongest inverse association was found for the consumption of nuts (OR 0.67; 0.61 to 0.75, p<0.001). With slight differences for some items, the results were basically the same when we estimated the OR for general obesity (). Contrary to expectations, we found a significantly direct, instead of inverse, association of the item combining margarine, butter and cream with obesity and average BMI, i.e., participants with a higher consumption of margarine, butter or cream exhibited a lower
BMI (adjusted difference: 0.44 kg/m2
; CI, 0.15 to 0.73, after adjusting for potential confounders and all the other items in the score). Participants answering ≥1 to the question How many servings of butter, margarine, or cream do you consume per day? (1 serving: 12 g)
had mainly a higher consumption of margarine (6 g/d), with minor consumptions of butter (2.6 g/d) or cream (0.6 g/d). Therefore, this item was mainly related to margarine consumption. When we used the FFQ to assess the association between consuming ≥1 serving/d of margarine, an inverse association with obesity was found with OR
0.84 (95% CI: 0.68–1.03, p
0.09) after adjusting for age, sex, centre and smoking. This inverse association between margarine and adiposity was weaker and statistically non-significant for abdominal obesity (WHtR>0.6) with OR
0.93 (0.74–1.17). No association was observed for butter or cream.
Multivariable-adjusted1 odds ratios (OR, 95% confidence intervals) for abdominal obesity and general obesity according to the fulfilment of each item included in the 14-point screener of adherence to the Mediterranean diet.
When we introduced separately all the 14 items in a model with BMI as the dependent variable, also adjusted for age, sex, smoking and center, we found that higher consumptions of red meat, soda drinks, and commercial bakery/sweets/cakes were significantly associated with higher average BMI, whereas higher consumption of wine, use of olive oil as the main culinary lipid, vegetables, and nuts were associated with lower average BMI (). High fruit consumption did not show a significant independent association with BMI (p
0.76). Similar associations were found when we used WHtR instead of BMI as the dependent variable (). In this analysis the association between high fruit consumption and lower WHtR approached the limit of statistical significance (p
Adjusted differences in BMI for 7 selected items in the 14-point score of adherence to the Mediterranean diet independently associated with BMI.
Adjusted differences in % waist-to-height ratio (95% confidence intervals)1 for selected items in the 14-point score of adherence to the Mediterranean diet independently associated with the waist-to-height ratio.