Have you noticed how some people can drink coffee after dinner and have no problem sleeping, while others sip the same amount and are up all night, ordering all kinds of stuff from infomercials?
According to Ruth Frechman, R.D., a spokesperson for the American Dietetic Association, tolerance for caffeine could be due to your genes, among other things.Here’s what she said in the August ’11 Prevention:
“The more you drink over time, the less it stimulates you. Age, weight and even your genes can make you more or less susceptible to caffeine’s effects as well.”
Remember that the main ingredient in most fat burners—not to mention all of the popular energy drinks—is caffeine.
If you use them or coffee regularly for a boost, you may want to take occasional cold-turkey breaks for a few days to rejuvenate the caffeine—and fat-burning—kick.