Is Coffee Good or Bad for Losing Weight?

Coffee drinkers who are trying to lose weight might wonder if that cup of java fits within their goals. While coffee and weight loss might not be directly related, the beverage can have both exercise and fat-burning benefits — as long as you're drinking it the right way.

Here's a look at the ways coffee can be good for losing weight and the mistakes that might hurt your weight-loss efforts.

There's evidence linking coffee to weight loss and weight control. One April 2015 study in the ​International Journal of Epidemiology​ looked at the dietary habits of more than 93,000 people to find patterns between coffee consumption and weight. The authors observed that people who drank more coffee had a lower risk of obesity, as well as a lower risk of type 2 diabetes.

It's important to note that this was just an observational study, so we can't draw any major conclusions from it. But it sets the stage for other research around coffee and weight loss, which has shown the following:

Drinking coffee may help you take in fewer calories by suppressing appetite, according to a December 2017 review in the ​International Journal of Food Sciences and Nutrition​. The reviewers found that drinking coffee a half hour to four hours before a meal led people to eat less.

The effect is only temporary, though: The review noted that drinking coffee three to four and a half hours before a meal didn't have much effect on food intake.

Interestingly, a small June 2013 randomized controlled trial in ​Obesity​ found a similar effect, but only for certain people. Specifically, people with overweight or obesity who drank a cup of coffee ate less at their following meal, but the coffee didn't seem to have the same effect on people who were at a "normal" weight.

Some other studies haven't found a strong link between coffee and lower appetite, so keep in mind that this benefit may not apply to everyone.

Coffee contains the naturally occurring stimulant caffeine, which can — at least briefly — increase your resting metabolic rate (aka your calorie-burning capacity).

Researchers from the Harvard T.H. Chan School of Public Health conducted a 24-week trial on 126 adults with overweight and found that those who drank four cups of coffee a day (compared to a placebo) lost a modest amount of body fat. The researchers said they thought the fat loss was caused by the caffeine increasing the drinkers' metabolism.

Drinking a cup of coffee one hour before hitting the gym can help you work out longer at a higher rate of intensity, so you will burn more calories before getting tired, according to a February 2015 study in the ​International Journal of Sport Nutrition and Exercise Metabolism​. The calorie-burning effect lasts long after you're done working out, too.

Additionally, an October 2014 study in the ​Journal of Applied Physiology​ showed that caffeine can trigger dopamine, the chemical that makes you feel pleasure. This means you might just enjoy your workout more.

A cup of black coffee contains fewer than 3 calories, per the USDA. Therefore, coffee in your diet only becomes harmful to weight loss when it's loaded with sugar, cream or other calorie-laden extras.

A single cup of coffee with 2 teaspoons of sugar and an ounce of half-and-half has 72 calories, according to the USDA. If you're drinking, say, three cups of the stuff daily, that's an extra 216 calories each day and 1,500 calories each week.

For the record, the American Heart Association recommends sugar make up no more than 100 to 150 calories a day (about 6 to 9 teaspoons worth), but according to the FDA, most Americans consume about an extra 270 calories a day in sugar, including in sweetened coffee.

Because caffeine is a stimulant, it has the potential to interfere with your sleep, especially if you drink it too close to bedtime. Drinking coffee in the afternoon might make it harder to fall asleep and also get in the way of the deep sleep you need to feel refreshed.

That's important because quality sleep is crucial for weight loss. Lack of good shut-eye can throw your hunger hormones out of whack, affect your willpower around food and exercise and even prompt your body to store more fat.

While that cup of black coffee comes with a host of health benefits and can give your athletic performance a boost, there are warnings about drinking too much. According to Mayo Clinic, drinking more than about four cups of coffee a day could make you feel nervous and irritable, and it may cause muscle tremors.

While none of these side effects directly impedes weight loss, they can keep you from feeling your best, which can in turn affect your motivation to eat well, exercise and generally stick to your weight-loss plan.