Study on the effect of the Mediterranean diet on obesity

The Mediterranean diet is a rich source of polyphenols, which have various positive effects on body fat distribution. This study led by Hila Zelicha investigated the effect of the so-called green Mediterranean diet, which contains twice as many polyphenols and includes less red/processed meat, on visceral adipose tissue.

In the 18-month diet program, 294 participants were randomized into three groups: (A) General healthy diet, (B) Mediterranean diet, (C) Green Mediterranean diet.

All groups combined their diet with physical activity. The two isocaloric Mediterranean diets included 28 g of walnuts daily. In addition, the Green Mediterranean Diet group consumed 3-4 cups of green tea and a shake of Wolffia globosa daily and reduced their meat consumption. Magnetic resonance imaging (MRI) was used to measure visceral adipose tissue.

Participants showed high study adherence (89.8%) and 79.3% performed a usable MRI. While both Mediterranean diets achieved moderate weight loss and waist circumference was similarly reduced, visceral fat loss doubled on the Green Mediterranean Diet.

Higher consumption of green tea, walnuts and Wolffia globosa, lower meat consumption, higher total plasma polyphenol levels (especially hippuric acid) and increased urinary levels of urolithin A were significantly associated with greater loss of visceral adipose tissue.

The green Mediterranean diet, enriched with plant polyphenols and reduced meat consumption, could be an effective dietary strategy to reduce visceral adipose tissue.