The effect of high-polyphenol Mediterranean diet on visceral adiposity: the DIRECT PLUS randomized controlled trial

  • Iris Shai (Owner)
  • Hila Zelicha Peer (Creator)
  • Nora Kloting (Other)
  • Alon Kaplan (Creator)
  • Anat Yaskolka Meir (Creator)
  • Ehud Rinott (Creator)
  • Gal Tsaban (Creator)
  • Yoash Chassidim (Sapir College) (Data Collector)
  • Matthias Blüher (Other)
  • Uta Ceglarek (Other)
  • Berend Isermann (Other)
  • Michael Stumvoll (Other)
  • Rita Nana Quayson (Creator)
  • Martin Von Bergen (Creator)
  • Beatrice Engelmann (Other)
  • Ulrike E. Rolle-Kampczyk (Other)
  • Sven Bastiaan Haange (Other)
  • Kieran M. Tuohy (Other)
  • Camilla Diotallevi (Other)
  • Ilan Shelef (Other)
  • Frank B. Hu (Other)
  • Meir J. Stampfer (Contributor)



Mediterranean (MED) diet is a rich source of polyphenols, which benefit adiposity by several mechanisms. We explored the effect of the green-MED diet, twice fortified in dietary polyphenols and lower in red/processed meat, on visceral adipose tissue (VAT). Methods In the 18-month Dietary Intervention Randomized Controlled Trial PoLyphenols UnproceSsed (DIRECT-PLUS) weight-loss trial, 294 participants were randomized to (A) healthy dietary guidelines (HDG), (B) MED, or (C) green-MED diets, all combined with physical activity. Both isocaloric MED groups consumed 28 g/day of walnuts (+ 440 mg/day polyphenols). The green-MED group further consumed green tea (3–4 cups/day) and Wolffia globosa (duckweed strain) plant green shake (100 g frozen cubes/day) (+ 800mg/day polyphenols) and reduced red meat intake. We used magnetic resonance imaging (MRI) to quantify the abdominal adipose tissues. Results Participants (age = 51 years; 88% men; body mass index = 31.2 kg/m2; 29% VAT) had an 89.8% retention rate and 79.3% completed eligible MRIs. While both MED diets reached similar moderate weight (MED: − 2.7%, green-MED: − 3.9%) and waist circumference (MED: − 4.7%, green-MED: − 5.7%) loss, the green-MED dieters doubled the VAT loss (HDG: − 4.2%, MED: − 6.0%, green-MED: − 14.1%; p < 0.05, independent of age, sex, waist circumference, or weight loss). Higher dietary consumption of green tea, walnuts, and Wolffia globosa; lower red meat intake; higher total plasma polyphenols (mainly hippuric acid), and elevated urine urolithin A polyphenol were significantly related to greater VAT loss (p < 0.05, multivariate models). Conclusions A green-MED diet, enriched with plant-based polyphenols and lower in red/processed meat, may be a potent intervention to promote visceral adiposity regression. Trial registration , NCT03020186
Date made available30 Sep 2022

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