If you’re having trouble with sleep, try eliminating caffeine from your diet by lunchtime, says Andrea Dunn, RD, LD, CDE, advanced practice dietitian for the Cleveland Clinic. As a natural central nervous system stimulant, caffeine can rev you up, sometimes for hours. “Caffeine has a half-life of three to four hours,” Dunn says. “That means that half the amount of caffeine you have at lunch is still in your system three to four hours later.” One study found that poor sleepers metabolize caffeine at a slower rate.
"You know that you are drinking too much coffee when Juan Valdez names his donkey after you."