When it comes to weight loss, caffeine can be a mixed bag—and it’s certainly no magic bullet. While it may be tempting to ramp up your caffeine intake as school and work ramp up this fall, it may not be the best thing for you or your medical weight loss program.

While some herbal and over-the-counter products say that the caffeine and other ingredients they contain can suppress appetite and increase metabolism, the scientific evidence for such claims is shaky at best. These so-called “weight loss enhancers” are not recommended because it’s often unclear what ingredients they contain, or at what potency. Worse, they could possibly interact in a negative way with other over-the-counter or prescription medications or cause complications for those with certain health conditions. We’ve mentioned this before, in our story on mall “nutrition supplements”. In short, save your money (and possibly your health) and steer clear of them.

Nobody is saying that you should quit caffeine altogether, but more study is needed to see if caffeine itself has any thermogenic (metabolism boosting) effect or if it can suppress appetite or cravings. What is  currently well known is that too much caffeine can lead to jitters, nervousness, and insomnia, among other negative side effects.

Caffeine is also a mild diuretic, which means it can cause water loss. On the medical weight loss program, we advocate the exact opposite—that our patients stay well hydrated because it helps lower a person’s overall fat percentage during weight loss, which is the real goal. Because any beverage containing caffeine may lead to a dehydrating effect, it’s important to balance that out by following up with an extra glass or two of water to compensate.

If someone wants a cup or two of coffee, green tea, or regular tea a day, that is completely reasonable. It’s no secret that caffeine can give one an energy boost, which is exactly why so many people drink it. The big problem with caffeine is that those beverages are often accompanied by extra calories. Coffee loaded up with sugar and cream, for example. Or a latte or mocha drink from a coffee stand that contains several servings of whole milk, plenty of flavored syrup, and whipped cream—all adding up to 500 calories or more!

So if you are a coffee or tea drinker, try to drink your beverages “straight” without all of the extra bells and whistles. When you do, the drinks weigh in at zero calories. If you absolutely must doctor them up, stick to skim milk and a measured amount of real cane sugar and make sure to factor those calories into your daily intake. Also, be sure to ask in the office for our low-calorie coffee module that can help you select the best beverage options.

One quick and easy tip: if you’re going to make a single substitution, substituting green tea for your usual coffee or black tea would be a wise move. It has a naturally sweet taste and is a good source of antioxidants. Preliminary studies show this beverage does seem to promote weight loss beyond the simple caffeine effect. With or without caffeine, you still need to eat a balanced diet, get regular exercise, and address and overcome any behavioral factors that might be playing a role. We’re here to help, but it’s important to remember that weight loss is a process, a journey, and it can take some time to get it right.