I did not say meat free.
The Mediterranean diet includes meat and fish, but it seems the key is a varied diet with plenty of grains and legumes and free of processed foods with high sugar content, antibiotics, hormones etc. along with daily physical effort and the social interaction of traditional family structure.
This as opposed to the modern western diet. The emerging microbiome studies and understanding seems to underpin the importance of a predominantly, but exclusively, plant based diet free of processed foods.