The Confusing Link Between Caffeine and Weight Loss

Drinking coffee can help you feel more alert, boost workout performance, contribute to a longer lifespan and reduce the risk of certain diseases like Alzheimer’s and Type 2 diabetes. However you get your caffeine fix — whether you’re a regular at the cafe, an at-home barista or enjoy other sources like tea and chocolate — you probably know some of the benefits of a caffeine pick-me-up. New research shows caffeine might also increase metabolism and help slow weight gain, even on higher-carb, higher-fat diets.

In a study published in the Journal of Functional Foods, researchers found rodents gained 16% less weight and accumulated 22% less body fat when their diets included caffeine extract from mate tea, which is equivalent to humans drinking four cups of coffee per day, the recommended maximum. In addition to the caffeine supplements, the rats consumed a higher-carb, higher-fat diet, with 45% of their calories coming from carbs, 40% from fat and 15% from protein.

Consuming caffeine could help alleviate the negative impact of a high-fat, high-sucrose diet on body composition thanks to the modulation of certain enzymes responsible for fat storage, says study co-author Elvira Gonzalez de Mejia, PhD, director of the division of nutritional sciences at the University of Illinois.

Other recent research also found people who drank four cups of coffee per day for 24 weeks experienced a 4% decrease in body fat. Caffeine might stimulate a thermogenic effect that heats brown fat, boosting metabolic rates and burning more calories, according to a study published in the journal Nature.

Some research shows drinking the equivalent of 8 ounces (1 cup) of coffee first thing in the morning was linked with consuming 10% fewer calories at breakfast. However, “the reduction was only a difference of 70 calories and the effect was not sustained,” notes study co-author Leah M. Panek-Shirley, PhD, assistant professor at SUNY Buffalo State College. Researchers concluded there was no significant decrease in BMI. Panek-Shirely believes “this study demonstrates the limitations of caffeine as a weight-loss supplement.”

More research is needed to determine whether caffeine can promote weight loss on its own, adds Michael Symonds, PhD, co-author of the Nature study and professor emeritus at the University of Nottingham. Symonds notes it would likely take “quite a lot of coffee and well beyond more than the normal amount [people drink] on a daily basis,” to trigger weight loss.

Though multiple studies have found associations between coffee and weight loss, others warn guzzling caffeinated beverages might have the opposite effect. Researchers at Cornell University found caffeine may increase sugar cravings because it changes how you perceive sweetness. In animal studies, drinking more than five cups of coffee per day was associated with weight gain and a higher risk of metabolic syndrome, a group of risk factors such as high blood pressure, high cholesterol and obesity.

What’s more, if you don’t enjoy the taste of black coffee and tend to add creamers, syrups and other add-ons, your coffee can easily become a sneaky calorie-bomb. What’s more, caffeine could cause gastrointestinal issues and headaches and is harder to metabolize for some people.

Coffee and other caffeine-containing drinks like tea can still be part of a healthy diet but shouldn’t be viewed as a magic bullet for weight loss. “Enjoy caffeinated substances in moderation and limit use before bed time,” advises Panek-Shirley. If you drink coffee, avoid sweetened lattes or mochachinos topped with whipped cream. Try to drink it black or add a small amount of milk. Remember to look at your diet as a whole and to also prioritize regular movement to ensure healthy, weight loss success.