Americans love a morning cup of coffee. Otherwise, Starbucks would never have achieved its iconic status. Who doesn’t recognize that familiar logo? We’re a nation of coffee drinkers. According to the Harvard School of Public Health, 54% of adults drink one or more cups of coffee every day. That’s not necessarily a bad thing. Research suggests coffee has health benefits. With its relatively high caffeine content, you might wonder whether drinking coffee helps with weight loss or weight control. Let’s see what the evidence shows.
Coffee and Weight Control
Research shows coffee drinkers tend to have a lower body weight than those who don’t drink coffee. Just as importantly, regular coffee drinkers seem to enjoy some protection against weight gain. In a study published in the American Journal of Clinical Nutrition, researchers followed almost 60,000 men and women over a 12-year period. Those men and women that consumed more caffeinated coffee over twelve years experienced less weight gain than those that drank less. Interestingly, participants who drank caffeinated tea OR coffee gained less weight than those who didn’t. Decaffeinated coffee didn’t offer the same benefit. In fact, decaf coffee consumption was linked to a slight increase in weight. The benefits of caffeinated coffee were greatest in women with a higher BMI, those that smoked and those who were less physically active.
One way caffeinated coffee may help with weight control is by the effects on thermogenesis. A study published in the American Journal of Clinical Nutrition showed a 100-milligram dose of caffeine increased resting metabolic rate by 3 to 4% in obese and non-obese individuals. The question is whether caffeine increases thermogenesis when you consume it on a regular basis. The activating effects of caffeinated coffee are reduced over time when you drink coffee regularly. That’s why you feel nervous and jittery when you first start drinking coffee and feel less so when you become a regular coffee drinker. Another study also found caffeine increased thermogenesis and energy expenditure. In this small study involving only 20 women, lean women experienced a greater rise in thermogenesis in response to caffeine than obese women did.
Does Coffee Suppress Appetite?
Another way drinking caffeinated coffee may help with weight control is by its effect on appetite control. Evidence suggests that caffeine has an appetite suppressant effect short-term. A recent study carried out in Athens, Greece confirms this. This study showed consuming caffeine prior to an “all-you-can-eat” lunch buffet reduced calorie consumption among overweight and obese participants but not participants of normal weight. The downside is the amount of caffeine that had an appetite-suppressive effect was around 526 milligrams of caffeine, the equivalent of about four 8-ounce cups of brewed coffee.
Caffeine has an effect on a variety of brain chemicals, one way it may reduce appetite. Unfortunately, that much coffee would be enough to cause side effects like palpitations, anxiety, nausea and problems sleeping in a number of people. Some people are more sensitive to the effects of caffeine than others. Drinking that many cups of coffee daily just to suppress appetite isn’t practical for most people.
Coffee, Calories and Chlorogenic Acid
Finally, coffee has no calories. The calories come from what you put into it. If you drink coffee unsweetened or sweetened with a calorie-free sweetener in place of beverages that contain calories, you might expect to experience some weight loss. Of course, many people can’t resist adding a few spoons of sugar and a generous dose of cream.
Coffee contains another chemical called chlorogenic acid that’s most abundant in green coffee beans. Roasted coffee beans have less. Some evidence suggests chlorogenic acid may promote weight loss, although it’s far from proven. One way it may do this is by altering intestinal glucose absorption. According to a meta-analysis of three different studies involving green coffee bean extract, participants lost an average of about 5 pounds taking green coffee bean extract supplement compared to a placebo. Other studies have also shown chlorogenic acid in green coffee bean extract may help with weight loss. Still, the benefits aren’t proven. Plus, the amount of chlorogenic acid in a cup of coffee is less than in a green coffee bean supplement where the beans haven’t been roasted.
Other Health Benefits of Coffee
A number of studies show coffee drinkers enjoy a lower risk for type 2 diabetes. What’s interesting is caffeine seems to temporarily reduce insulin sensitivity, suggesting caffeinated coffee might have a short-term negative impact on glucose control. How can you explain the fact that coffee seems to lower the risk for type 2 diabetes? Coffee may lower the risk of diabetes by its effect on body weight. As other research shows, coffee drinkers tend to have a lower body weight.
Type 2 diabetes isn’t the only disease that coffee may lower the risk of. Preliminary research suggests enjoying a few cups of coffee daily may reduce the risk of Parkinson’s disease, gallbladder disease, certain types of liver disease, and even some types of cancer including prostate cancer, estrogen receptor negative breast cancer and cancer of the uterus.
Contrary to popular belief, drinking moderate amounts of coffee (less than three cups a day) doesn’t increase the risk for heart disease and may actually lower the risk by reducing blood vessel inflammation. Coffee also doesn’t significantly raise your cholesterol either unless you drink unfiltered coffee made with a French press or Turkish coffee. Chlorogenic acid in coffee is also an antioxidant. In fact, coffee is the number one source of antioxidants in the American diet. It would be best to diversify a little and get more antioxidants from fruits and vegetables instead!
The Bottom Line
Drinking coffee may modestly boost your metabolism. In addition, large amounts may help with appetite control. Still, drinking coffee in and of itself probably won’t lead to a significant amount of weight loss, although it may help with weight control. Still, drinking moderate amounts of coffee (2-3 cups a day) may have other health benefits, including lowering your risk for some health problems.
If you drink coffee, do it in moderation. You can enjoy most of the health benefits by sticking to 2-3 cups a day. Drinking more than that increases your risk for side effects like nervousness and problems sleeping. Coffee can be part of a healthy weight control diet – but don’t overdo it.
References:
Harvard School of Public Health. “Coffee By the Numbers”
Am J Clin Nutr March 2006 vol. 83 no. 3 674-680.
Family Practice News. “Can Coffee Reduce Weight?”
Am J Clin Nutr January 1989 vol. 49 no. 1 44-50.
Am J Physiol. 1995 Oct;269(4 Pt 1):E671-8.
Today’s Dietitian. Vol. 16 No. 1 P. 58
Harvard Health Publications. “What is it about coffee?”
Diabetes Care. Jun 2009; 32(6): 1023-1025.
Related Articles By Cathe:
Can Drinking Coffee Boost Your Metabolism?
