Carotenoid bioavailability from raw vegetables and a moderate amount of oil in human subjects is greatest when the majority of daily vegetables are consumed at one meal.
Goltz SR, Sapper TN, Failla ML, Campbell WW, Ferruzzi MG. Carotenoid bioavailability from raw vegetables and a moderate amount of oil in human subjects is greatest when the majority of daily vegetables are consumed at one meal. Nutr Res. 2013 May; 33(5):358-66.