Table 2.

Population–intervention–comparison–outcome (PICOS) criteria for study inclusion and exclusion.

Criteria category	Inclusion	Exclusion
Population	Overweight and obese adults with or without type 2 diabetes	Normal weight adults Children/animals
Intervention	Polyphenols	The intervention is not polyphenols
Comparators	Overweight and obese adults with or without type 2 diabetes not treated with polyphenols	Normal weight adults Children/animals
Outcome measure	Primary outcome is lipid profile and secondary outcomes are blood glucose, HbA1c (%), HOMA-IR, weight and body mass index	Lipid profile not assessed
Study design	Randomised control trials	Observational studies, review studies, case reports, pilot studies