Enjoy Caffeine in Moderation

Q: What is your take on caffeine — is it good or bad? Should I skip it altogether, or maybe just stick to a daily limit?

A: 

Caffeine in moderation is a good thing. It improves cognitive function, inhibits insulin resistance, and speeds up your metabolism. The trick is not to overdo it! Too much caffeine can actually make us gain weight by burning out our adrenal glands and releasing stress hormones. For this reason, 400 milligrams (mg) a day should be the limit. (That’s the equivalent of one to two large cups of coffee, depending on how strongly it’s brewed.)

Some sources of caffeine are better than others. Organic, filtered coffee (not doctored up with sugar, artificial sweeteners, or cream) is okay. Green tea is a better a choice because it promotes fat oxidation and is believed to improve insulin sensitivity. Limit your intake of caffeinated beverages to one or two a day — and because caffeine is a diuretic, you should drink one glass of water for every caffeinated drink. Also, you should have your last caffeinated drink before noon so that it doesn’t interfere with your sleep.

Get more fitness tips from Jillian Michaels.

Last Updated: 10/31/2011

Often called "TV’s toughest fitness trainer," Jillian Michaels has appeared on the U.S. and Australian versions of The Biggest Loser. Jillian is also the author of three books, Master Your Metabolism, Winning by Losing and Making the Cut, and the creator of the online weight-loss program www.jillianmichaels.com.