The Green Mediterranean diet can deliver significant reduction in body fat, study finds

Reducing visceral fat is considered the true goal of weight loss as it is a more important indicator than a person’s weight

[Oct. 24, 2023: Ehud Zion Waldoks, Ben-Gurion University of the Negev]

Subsequent analysis found that the green Med diet reduced visceral fat by 14%, the Med diet by 7% and the healthy diet by 4.5%. (CREDIT: Creative Commons)

The green Mediterranean diet (MED) significantly reduces visceral adipose tissue, a type of fat around internal organs that is much more dangerous than the extra "tire" around your waist. The green Mediterranean diet was pitted against the Mediterranean diet and a healthy diet in a large-scale clinical interventional trial- the DIRECT PLUS. Subsequent analysis found that the green Med diet reduced visceral fat by 14%, the Med diet by 7% and the healthy diet by 4.5%. The study was published in BMC Medicine.

Reducing visceral fat is considered the true goal of weight loss as it is a more important indicator than a person's weight or the circumference of their waist. Visceral fat aggregates over time between organs and produces hormones and poisons linked to heart disease, diabetes, dementia and premature death.

The research was led by Prof. Iris Shai of Ben-Gurion University of the Negev, Israel, an adjunct Professor from the Harvard School of Public Health, and an Honorary Professor, University of Leipzig, Germany, together with her doctoral student Dr. Hila Zelicha and Italian, German, and American colleagues.

The DIRECT-PLUS trial research team was the first to introduce the concept of the green-Mediterranean diet. This modified MED diet is further enriched with dietary polyphenols and lower in red/processed meat than the traditional healthy MED diet.

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On top of a daily intake of walnuts (28 grams), the participants consumed 3-4 cups of green tea/day and 100 grams (frozen cubes) of duckweed green shake/day. The aquatic green plant duckweed is high in bioavailable protein, iron, B12, vitamins, minerals, and polyphenols and substituted meat intake.

The team has shown in previous studies that the green MED diet has a variety of salutary effects ranging from the microbiome to age-related degenerative diseases.

Two hundred and ninety four participants took part in the 18-month long trial.

"A healthy lifestyle is a strong basis for any weight loss program. We learned from the results of our experiment that the quality of food is no less important than the number of calories consumed and the goal today is to understand the mechanisms of various nutrients, for example, positive ones such as the polyphenols, and negative ones such as empty carbohydrates and processed red meat, on the pace of fat cell differentiation and their aggregation in the viscera," says Prof. Shai.

Prof. Iris Shai (pictured above) of Ben-Gurion University of the Negev, Israel

"A 14% reduction in visceral fat is a dramatic achievement for making simple changes to your diet and lifestyle. Weight loss is an important goal only if it is accompanied by impressive results in reducing adipose tissue," notes Dr. Hila Zelicha.

This work was funded by grants from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Project number 209933838- SFB 1052; the Rosetrees trust (grant A2623); Israel Ministry of Health grant 87472511; Israel Ministry of Science and Technology grant 3-13604; and the California Walnuts Commission.

Eighteen-month changes in abdominal adipose tissues (mean (SE)) between the intervention groups (n = 286). After 18 months of intervention, all groups reduced all three abdominal adipose tissues significantly. Significant differences in VAT% change between the green-MED group and MED, as well as HDG groups, were observed after adjustment for age, sex, and waist circumference change. Deep SAT, deep subcutaneous; superficial SAT, superficial subcutaneous; HDG, healthy dietary guidelines; MED, Mediterranean; VAT, visceral adipose tissue. *Significant within-group change vs. baseline at the 0.05 level. **Significant differences between the groups at the 0.05 level. (CREDIT: BMC Medicine)

None of the funding providers was involved in any stage of the design, conduct, or analysis of the study and they had no access to the study results before publication.

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

Multivariate models for the assessment of the associations between nutritional components of the green-MED diet with changes in VAT% adjusted for age and sex. Mankai consumption was adjusted for age and referred to the green-MED group only. (CREDIT: BMC Medicine)

Researchers include: Hila Zelicha1, Nora Kloting2, Alon Kaplan1, Anat Yaskolka Meir1, Ehud Rinott1, Gal Tsaban1, Yoash Chassidim3, Matthias Bluher4, Uta Ceglarek2, Berend Isermann2, Michael Stumvoll2, Rita Nana Quayson2, Martin von Bergen2, Beatrice Engelmann2, Ulrike E. Rolle‑Kampczyk2, Sven‑Bastiaan Haange2, Kieran M. Tuohy5, Camilla Diotallevi5, Ilan Shelef6, Frank B. Hu7,8,9, Meir J. Stampfer7,8,9 and Iris Shai1,9*

  • Faculty of Health Sciences, The Health & Nutrition Innovative InternationalResearch Center, Ben-Gurion University of the Negev, P.O. Box 653, 84105 Be’er Sheva, Israel.

  • Department of Medicine, University of Leipzig, Leipzig, Germany.

  • Department of Engineering, Sapir Academic College, Ashkelon, Israel.

  • Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Leipzig, Germany.

  • Department of Food Quality and Nutrition, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all’Adige, Trentino, Italy.

  • Soroka University Medical Center, Be’er Sheva, Israel.

  • Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA.

  • Harvard Channing Division of Network Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, MA, USA.

  • Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA.

Note: Materials provided by Ben-Gurion University of the Negev. Content may be edited for style and length.

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Joseph Shavit
Joseph ShavitSpace, Technology and Medical News Writer
Joseph Shavit is the head science news writer with a passion for communicating complex scientific discoveries to a broad audience. With a strong background in both science, business, product management, media leadership and entrepreneurship, Joseph possesses the unique ability to bridge the gap between business and technology, making intricate scientific concepts accessible and engaging to readers of all backgrounds.