A 16-ounce cup of brewed coffee can have up to 320 milligrams caffeine -- slightly more than what's considered a moderate dose, according to MedlinePlus.com. The caffeine in coffee and other beverages that contain caffeine, such as tea and diet cola, is said to help you lose weight. However, medical experts say that the benefits of coffee for weight loss are very modest.
Coffee and Caffeine
Caffeine is a natural substance in coffee and cocoa beans, tea leaves and kola nuts; it's also added to certain drugs and weight loss supplements. Caffeine is a stimulant that affects your central nervous system, making you feel awake, mentally alert and energetic. Caffeine in food and beverages is measured in milligrams. An 8-ounce cup of brewed black coffee has between 102 to 200 mg caffeine and only 2 calories.
Coffee may actually contribute to weight gain. According to an article in The Huffington Post, if you add milk, cream or sugar to your coffee, you rack up the calories. If a cup of warm coffee begs you to have a donut or biscotti with it, then you are doing your body more harm than good. Caffeine may slightly boost thermogenesis, the process by which your body burns calories it gets from food and beverages. However, the Center for Science in the Public Interest, or CSPI, notes that caffeine's effect on your weight is both negligible and temporary. Heavy coffee drinkers may experience caffeine's undesirable side effects, such as insomnia, anxiety, shakiness and an upset stomach.
Weight Loss Results
According to CSPI, consuming 100 mg of caffeine may increase your metabolism slightly so that you burn an extra 75 to 100 calories a day. However, people who drink a lot of coffee or who use caffeine in other forms don't see long-term weight loss results. CSPI goes on to note that one possibility is that people who use caffeine consume extra calories to make up for the extra calories burned. Yet another theory is that people develop a tolerance to caffeine; over time, it loses its ability to stimulate your metabolism. Coffee may not help you lose weight at all -- in fact, it might have the opposite effect. Gourmet coffee drinks are laden with added sugar and saturated fat and contain a surprising number of calories.
Calories from Coffee
The drinks at popular chain coffee houses may have the same number of calories as your favorite confection. A 20-ounce white chocolate mocha made with whole milk and topped with whipped cream weighs in at 400 calories. A cafe mocha of the same size has 450 calories. One of these very large drinks can make up more than 20 percent of your daily calories, if you eat a 2,000-calorie diet. A tablespoon of fat-free milk and packet of artificial sweetener gives your cup of coffee only 7 calories.