Green leafy vegetables (GLV) are known for their cardiovascular health benefits. However, the effects of their serving size on delaying carbohydrate and lipid digestion remain unclear. This study investigated the impact of varying MyPlate-recommended GLV serving sizes on the digestibility of carbohydrates and lipids and antioxidant activity during in vitro gastrointestinal digestion. Eight GLV including Asteraceae (cos, green oak, red oak, loose-leaf) and Brassicaceae (cabbage, cauliflower, broccoli, Chinese cabbage) vegetables were incorporated into mixed meals at 0.5, 1.0, and 1.5 times the MyPlate recommendation. The results showed that the total phenolic content (TPC) ranged from 5.77 to 9.46 mg GAE/g extract. Nitrate accumulation exhibited a higher content in Asteraceae (590.90-1155.04 mg NO