Does green tea catechin enhance weight-loss effect of exercise training in overweight and obese individuals? a systematic review and meta-analysis of randomized trials.

Farhad Gholami, Jose Antonio, Mohadeseh Iranpour, Jason Curtis, Flavia Pereira

Journal: Journal of the International Society of Sports Nutrition 2024;21(1):2411029

PMID: 39350601

Plain Language Summary

Obesity is marked by excessive fat accumulation due to an imbalance between energy intake and expenditure and is a major risk factor for metabolic and non-metabolic diseases. This study aimed to assess whether green tea supplementation combined with exercise training offers greater benefits for weight loss and lipid profile improvements compared to exercise alone in overweight and obese individuals. This systematic review and meta-analysis included ten randomised controlled trials involving 476 participants, with 199 assigned to the exercise plus green tea (EX+GT) group, 196 to the exercise plus placebo (EX+P) group, and the remainder to other study arms. Results indicated that green tea supplementation alongside exercise training produced a small but consistent reduction in weight-related measures. However, it did not confer additional benefits on lipid profiles, including triglycerides, low-density lipoprotein, high-density lipoprotein, or total cholesterol. Authors concluded that green tea catechin intake, when combined with exercise, has a modest but consistent effect on weight reduction compared to exercise alone, but no effect on blood lipid levels.

Abstract

BACKGROUND

Green tea (GT) is a common component of supplements known as fat burners. It has gained popularity as an ergogenic aid for weight reduction to assist with obesity management. This systematic review and meta-analysis aim to explore the effect of green tea ingestion coupled with exercise training (EX) on body composition and lipid profile in overweight and obese individuals.

METHODS

Two independent researchers systematically searched the electronic databases of PubMed, Web of Science, and Scopus. Studies with a randomized-controlled design to compare the effect of green tea in conjunction with exercise training (EX+GT) versus exercise training alone (EX+P) in overweight or obese participants were included.

RESULTS

Of the 1,015 retrieved studies, 24 were identified to undergo full-text review, out of which 10 randomized trials met the inclusion criteria. EX+GT versus EX+P had a small and consistent effect on weight [Standardized mean difference (SMD) = -0.30, CI: -0.53 to -0.07], BMI [SMD = -0.33 CI: -0.64 to -0.02] and fat reduction [SMD = -0.29, CI: -0.57 to -0.01] and there was no evidence of heterogeneity across the trials. When compared to EX+P, EX+GT had no greater effect on lipid profile improvement [triglyceride: SMD = -0.92, CI: -1.30 to 0.49; LDL: SMD = -1.44, CI: -0.73 to 0.82; HDL: SMD = 0.56, CI -0.71 to 0.46; and total cholesterol SMD = -0.54, CI -0.85 to 0.13].

CONCLUSIONS

Current evidence suggests that green tea could have quite minimal additive benefit over exercise-induced weight loss. However, incorporation of green tea into exercise training does not seem to exert additional benefits on lipid profile and it warrants further investigations in the future.

Address: Shahrood University of Technology, Department of Physical Education and Sport Sciences, Faculty of Physical Education, Shahrood, Iran.; Nova Southeastern University, Department of Health and Human Performance, Davie, FL, USA.; Keiser University, Department of Exercise and Sport Science, West Palm Beach, FL, USA.

DOI: 10.1080/15502783.2024.2411029