Researchers in Iran, Saudi Arabia and China conducted the 12-week trial to test how HIFT and spinach thylakoid supplementation, alone and in combination, affect body composition, metabolic health, and myokine signaling in men with obesity.
They wrote that the “thylakoid supplementation may provide modest, complementary anti-inflammatory benefits” to exercise.
Targeting myokines to reduce obesity
Obesity has risen sharply in recent decades and now drives widespread metabolic and inflammatory disorders.
It involves chronic low-grade inflammation and disruption of the TGF-β signaling pathway, which regulates cellular growth and metabolism. Elevated TGF-β activity can promote pathological fat accumulation.
Key members of the TGF-β family regulate energy homeostasis: Myostatin inhibits muscle growth and promotes fat gain, while follistatin and decorin counteract myostatin, enhance muscle mass, and improve insulin sensitivity. In contrast, Activin A increases under inflammatory conditions and worsens metabolic dysfunction.
Skeletal muscle releases myokines during exercise that can mitigate these obesity-related disturbances. HIFT is known to alter myokine secretion and reduce body fat through intense muscular activation.
Nutritional strategies such as thylakoid supplementation also show anti-obesity potential by delaying fat digestion, increasing satiety hormones, and suppressing ghrelin, the ‘hunger hormone’. However, the researchers of the new study noted evidence for thylakoid efficacy remains mixed, particularly in physically active populations.
Because HIFT targets muscle-derived myokines and thylakoids influence appetite regulation and inflammation, they suggested the combined effects may complement each other.
HIFT and spinach thylakoids boost metabolic health in obese men
The researchers recruited 44 obese sedentary men who were randomized into four groups: placebo (PG), thylakoid supplement (SG), training + placebo (TPG), and training + thylakoid supplement (TSG). The researchers prepared the supplement by blending and filtering fresh baby spinach leaves, treating to separate the thylakoids at a specific acidity (pH 4.7), and freeze-drying into a stable green powder.
The training groups completed supervised HIFT sessions - which followed a standardized CrossFit-based structure - three times per week, while non-training groups maintained their habitual lifestyles. The researchers measured body mass, height, fat mass, and fat-free mass. Participants consumed 5 g/day of spinach-derived thylakoids or a matched placebo 30 minutes before lunch.
Researchers collected fasting blood samples before and after the intervention to assess plasma concentrations of follistatin, myostatin, decorin, activin A, and TGF-β1. They also measured lipid profiles, glucose, insulin, and insulin resistance.
Resulting data indicated HIFT was the main driver of improvement, increasing beneficial myokines like decorin and follistatin, reducing harmful markers like myostatin, TGF-β1, and activin A, lowering body fat, improving lipid profiles, and reducing insulin resistance.
The thylakoid supplementation produced some positive changes, mainly in myokine levels and metabolic markers; however, it did not lead to major changes in body fat, fitness, or metabolic health by itself.
The combination of HIFT and thylakoids produced the greatest overall benefits, leading to the largest improvements in body composition, blood lipids, glucose control, and insulin sensitivity.
Analyses showed that higher decorin and follistatin levels were linked to lower body fat and better metabolic health, while higher myostatin, activin A, and TGF-β1 were associated with obesity, dyslipidemia, and insulin resistance, highlighting a strong link between muscle-derived signals and metabolic health in men with obesity.
“Although thylakoid supplementation did not yield a statistically significant clinical advantage over exercise alone in general markers—such as fat mass and lipid profiles—it induced specific enhancements in the expression of muscular anabolic markers,” the researchers concluded.
“Collectively, these results underscore the centrality of HIFT as the primary interventional pillar, suggesting that supplementation serves merely as an adjunctive approach to bolster specific signaling pathways within skeletal muscle.”
They suggested future studies should include larger and more diverse populations, and in order to better understand mechanisms of action, future work should combine blood measurements with muscle biopsies and gene expression analyses to identify the true tissue sources and mechanisms behind myokine changes.
Journal: Nutrients. “Adipo-Myokine Modulation in Obesity: Integrative Effects of Spinach Thylakoids and Functional Training in Men with Obesity: A Randomized Controlled Clinical Trial.” doi:10.3390/nu18030509; Authors: Razi, O. et al.
