Your body absorbs caffeine quickly, but it also expels it nearly as fast: within five to seven hours, 50 percent of it is gone from your system and 75 percent is gone after 10 hours. Drinking coffee later in the day can keep you up, but if you down your afternoon latte at least six hours before bedtime, you should sleep just fine. Keep in mind, however, that everyone is different, so some people may be more sensitive to caffeine’s effects than others.
On the surface, caffeine can come across as just another stimulant. But dig deeper and you’ll discover this psychoactive drug actually has some very real benefits. According to V. Wendy Setiawan, associate professor at the Keck School of Medicine, the high levels of antioxidants and other compounds in coffee "have been related to better insulin sensitivity, liver function, and reduced chronic inflammation." Further, when used correctly, caffeine can be a useful supplement, helping to improve memory and fitness and even reducing heart disease and stroke risks. Best of all, caffeine comes in many different forms, so you have endless choices on how to enjoy its perks.
Have you ever put butter in your coffee? It's a great way to optimize a high-fat diet.