Your Metabolic Health is Important

Metabolic health means having minimal belly fat, normal blood sugar, normal blood pressure, stable appetite and energy, and muscles, bones and joints that let you be active.  And all of this with no medication required.  It means optimal functioning of the conversion of food and drink into energy.  A metabolically healthy body is effectively regulating three primary systems, blood sugar, blood lipids (fats), and blood pressure. When these systems are operating smoothly, the body can easily extract energy from foods, store that energy appropriately and use it when it is needed.  Being metabolically healthy means reaching a level of wellness that goes beyond simply the absence of disease. (1)

Metabolic health can be tracked with five clinical measurements. (1)

• Fasting blood sugar – A reading of 5.5 mmol/L or more reveals a reduced ability to regulate blood sugar
• Triglycerides – This type of fat should be below 1.7 mmol/L
• HDL (High-Density Lipoprotein) cholesterol) – This type of fat should be above 1 mmol/L for men and above 1.3 mmol/L for women. HDL cholesterol helps to remove excess cholesterol from the body.
• Blood Pressure – This is the force that blood exerts on the walls of arteries. A level of 130/80 mmHg or higher denotes high blood pressure.
• Waist Circumference – This measures the amount of fat stored around the abdomen (aka visceral fat). This type of fat is linked to increased metabolic risk. Waist circumference measurements should be less than 101 cm (40”) for men and less than 89 cm (35”) for women.

Failure to maintain healthy levels of three or more of these levels is called Metabolic Syndrome.  This is not a disease in itself but a cluster of risk factors that significantly increase the likelihood of developing serious chronic illnesses. (1)

 

Research on Metabolic Health (2)

In an ongoing study, investigators are looking into the effects on aging of a Mediterranean diet that is rich in plants, including seeds, and low in processed and red meats, specifically beginning in middle age when weight begins to creep up, cognitive function starts to decline and cardiovascular and metabolic risks rise.  They hypothesized that long-term intake of a Mediterranean diet along with physical activity would be able to halt or even reverse some of the usual declines in health with age, and further, that such a lifestyle could modify the health of the gut microbiome.  This analysis followed participants using magnetic resonance imaging (MRI) to examine fat in the abdomen and around the liver and heart and for brain assessments.  They also used cognitive tests and measured changes in the gut microbiome.

The trial was looking specifically for metabolically unhealthy participants.  They were recruited from among the workers at the Nuclear Research Center in the Negev Desert near Dimona, Israel.  294 participants were found who had excess abdominal fat (indicated by waist circumference over 102 cm for men and over 88 cm for women) and had elevated triglycerides and/or low HDL cholesterol.  This isolated research center was able to provide a daily free lunch conforming to the dietary assignment of each participant.  Also on site were medical facilities and a fitness centre.

Participants were randomly placed into one of three different intervention groups;

• Group 1: These participants received free gym memberships and education sessions along with a workout program for moderate-intensity physical activity which included both aerobic and strength training.  They also received general guidelines on healthy eating.
• Group 2: These participants received the same physical activity program as Group 1 with the addition of adopting a Mediterranean diet (MED diet) that was “rich in vegetables and legumes and low in red meat, with poultry and fish replacing beef and lamb”. They were also provided with a daily ounce (28 grams) of walnuts to add to their diet.
• Group 3: These participants received the same programs and the walnuts as did Group 2 with the additions of greens and an intensification of their Mediterranean diet into a green-MED diet, one even lower in poultry, red and processed meat and higher in fish. They were also instructed to drink three to four cups of green tea per day and to add 100 grams of frozen cubes of Mankai (a high-fiber, high-protein aquatic plant, part of the family of plants known commonly as duckweeds) to a green smoothie which was to take the place of some of the animal protein intake at their meal.  These additions would significantly raise the amount of polyphenols in their diet.  Polyphenols are plant compounds with antioxidant and anti-inflammatory properties that may lower blood sugar, blood pressure, and heart disease risk and are thought to be behind the health benefits associated with the Mediterranean diet.

All three groups received a similar number of group sessions and level of personal guidance during the study.

Many findings from this study have been published.  Here are some of their results. (3,4,5,6,7,8,9,10)

• After 6 months on the program, participants in Group 3 had lost an average of 6.3 kg, while those in Group 2 lost an average of 5.4 kg and those in Group 1 lost an average of 1.5 kg.
• Those in Group 3 had a larger reduction in all of the following evaluations: waist circumference (indicating more loss of visceral fat), low-density lipoprotein cholesterol (LDL-C) levels, diastolic blood pressure, insulin resistance and Hs-CRP (a measure of inflammation).
• Participants in Group 3 lost 38.9% of the excess fat in their livers which was almost double the loss experienced by Group 2 participants at 19.6% and more than three times the loss of Group 1 participants which was 12.3%. Loss of liver fat was also linked to more diversity in the gut microbiome.
• Group 3 participants also had more than double the loss of visceral fat at 14.1% compared to 6% in those in Group 2 and 4.2% in those in Group 1. Visceral fat, fat stored around the organs in the abdomen, is the most dangerous type of fat.  This positive result was attributed to higher consumption of green tea, walnuts and duckweed, and lower red meat intake.
• Ghrelin is a hormone associated with hunger. Lower levels of ghrelin are linked to obesity and metabolic syndrome. Group 3 participants had the greatest increase in ghrelin levels at 10.5% compared to 5.4% in those in Group 2 and 1.3% in those in Group 1.
• Group 3 participants had the most significant increase in the healthiness of the gut microbiome. This is attributed to higher intake of polyphenol-rich plants and lower intake of red and processed meats.  This change was also associated with better cardiometabolic health such as loss of weight, healthy blood pressure levels and improvements in insulin sensitivity.
• The brain loses volume during aging and it is those with the greatest loss of brain volume who experience the largest loss of cognitive function. Participants underwent baseline brain MRI scans at the start of the study and again after 18 months on the study. The changes in brain volume in the brains of both Group 2 and Group 3 participants were significantly improved compared with those of Group 1 with the best outcomes in the green-MED group. Greater intake of Mankai, green tea and walnuts and less red and processed meat consumption were associated with reduced brain loss.

 

The Takeaway

In summary, a green-MED Mediterranean diet rich in plants, including green tea and leafy greens like Mankai (all of which offer an abundance of dietary polyphenols), and are low in processed and red meats, along with regular moderate-intensity physical activity promote better metabolic health.  This means blood pressure levels in the healthy range, optimal lipid levels, lower waist circumference, less fat around the abdomen and in the liver, slower aging of the brain, higher insulin sensitivity and a healthy well-functioning gut microbiome.

You can easily create these conditions for yourself.

• Plan your meals around whole fruits and vegetables, legumes, whole grains, nuts and seeds.
• Enjoy two or three cups of green tea daily. Green tea can be an acquired taste but, if you start with small amounts you’ll soon come to appreciate its subtle fresh flavour.
• Don’t worry about trying to find Mankai, a plant traditionally consumed in Southeast Asia. There are many other leafy greens available to take its place. Try them out and find your favourites.  Choose from kale, spinach, Swiss chard, arugula, bok choy, beet greens, collard greens, turnip greens, watercress, cabbage and Romaine lettuce.  Mix them up for different tastes and textures.
• Make a handful of walnuts a daily snack.

Almost as important as emphasizing healthy fruits and vegetables is to cut back on foods sourced from animals.  Your stomach can only hold so much.  If you are filling it with processed foods, red meats, eggs and dairy products there won’t be much room left for foods that offer optimal health.

As you progress on your journey towards a healthier body, you’ll be rewarded by more than just the knowledge that you are lowering your risk of chronic diseases and increasing the well-being of your whole body.  You’ll have more energy.  Your sleep will improve.  You’ll likely lose weight.  Your skin health will be enhanced.  You’ll reduce your impact on the environment.  You’ll add years to your life.  Even your mood will lift.  And you’ll discover that plant-based eating is delicious.

 

SOURCES;

1 https://scienceinsights.org/what-is-the-definition-of-metabolic-health/

2   https://clinicaltrials.gov/study/NCT03020186#publications; Effects of Green-MED Diet Via the Gut-fat-brain Axis (DIRECT-PLUS)

3  Yaskolka Meir A, Rinott E, Tsaban G, et al. Effect of green-Mediterranean diet on intrahepatic fat: the DIRECT PLUS randomised controlled trial. Gut 2021;70:2085-2095.

4  Kaplan, A., Zelicha, H., Yaskolka, Meir A., Rinott, E., Tsaban, G., Levakov, G., Prager, O., Salti, M., Yovell, Y. et al.  The effect of a high-polyphenol Mediterranean diet (Green-MED) combined with physical activity on age-related brain atrophy: the Dietary Intervention Randomized Controlled Trial Polyphenols Unprocessed Study (DIRECT PLUS). Am J Clin Nutr. 2022 May 1;115(5):1270-1281. Doi: 10.1093/ajcn/nqac001.

5  Zelicha, H., Kloting, N., Kaplan, A. et al. The effect of high-polyphenol Mediterranean diet on visceral adiposity: the DIRECT PLUS randomized controlled trial. BMC Med 20, 327 (2022). https://doi.org/10.1186/s12916-022-02525-8

6  Yaskolka, Meir A., Keller, M., Hoffmann, A., Rinott, E., Tsaban, G., Kaplan, A., Zelicha, H., Hagemann, T., et al.  The effect of polyphenols on DNA methylation-assessed biological age attenuation: the DIRECT PLUS randomized controlled trial. BMC Med. 2023 Sep 25;21(1):364. Doi: 10.1186/s12916-023-03067-3.

7  Zelicha, H., Kaplan, A., Yaskolka, Meir A, et al. Altered proteome profiles related to visceral adiposity may mediate the favorable effect of green Mediterranean diet: the DIRECT-PLUS trial. Obesity (Silver Spring). 2024;32(7):1245-1256. Doi:10.1002/oby.24036.

8  Pachter, D., Kaplan, A., Tsaban, G., Zelicha, H., Meir, A.Y., Rinott, E., Levakov, G., Salti, M., Yovell, Y., et al.  Glycemic control contributes to the neuroprotective effects of Mediterranean and green-Mediterranean diets on brain age: the DIRECT PLUS brain-magnetic resonance imaging randomized controlled trial. Am J Clin Nutr. 2024 Nov;120(5):1029-1036. Doi: 10.1016/j.ajcnut.2024.09.013. Epub 2024 Sep 14.

9  Klein, H., Zelicha, H., Yaskolka, Meir A., Rinott, E., Tsaban, G., Kaplan, A., Chassidim, Y. et al.  Visceral adipose tissue area and proportion provide distinct reflections of cardiometabolic outcomes in weight loss; pooled analysis of MRI-assessed CENTRAL and DIRECT PLUS dietary randomized controlled trials. BMC Med. 2025 Feb 4;23(1):57. Doi: 10.1186/s12916-025-03891-9.

10  Pachter, D., Yaskolka, Meir A., Kaplan, A., Tsaban, G., Zelicha, H., Rinott, E., Levakov, G., Finkelstein, O., et al.  Serum Galectin-9 and Decorin in relation to brain aging and the green-Mediterranean diet: A secondary analysis of the DIRECT PLUS randomized trial. Clin Nutr. 2025 Oct;53:99-108. Doi: 10.1016/j.clnu.2025.08.021. Epub 2025 Aug 23.