Preparation of spinach thylakoids and placebo
Fresh baby spinach leaves (Spinacia oleracea) were used to prepare of thylakoid membranes according to previously registered protocols (Powder samples were packed in identical sachets with each sachet containing 5 g of thylakoid or 5 g of cornstarch powder. The contents of the sachets were dissolved in a glass of water and consumed by participants 30 min before lunch. Packages were coded and distributed monthly by a third person who was not involved in any other aspects of the study. A supplement consumption chart, which was provided to remind participants to consume their daily supplements, was returned at each visit to ensure compliance. Participants also received daily text messages and weekly phone call reminders to consume the supplements. The participants were asked to return the remaining sachets at each visit to allow monitoring of; compliance. Adherence was deemed acceptable when ≥80% of the supplements were consumed.