Why do i get tired when i eat? ADVERTISEMENT 675 viewsJanuary 31, 2013 0 Patricia January 31, 2013 0 Comments 8 Answers ActiveVotedNewestOldest 0 Joanne0 Posted 0 Comments Digestion takes up a lot of energy. Blood is shunted away of larger muscles and shunted towards the part of the body that requires the energy. That’s why it is so important to leave heavy meals for when one doesn’t need to engage in labor-intensive or cognitive intensive activities. Best! You are viewing 1 out of 8 answers, click here to view all answers. Register or Login