Can coffee reduce weight?

Caffeine in the form of tea and coffee is the most widely consumed, socially acceptable stimulant around the globe. More than 150 million people in the United States drink coffee daily, with an average intake of two cups (which contains about 280 mg of caffeine).

Caffeine results in the release of excitatory neurotransmitters. Caffeine may increase energy expenditure and has been associated with reduced body mass. Studies have observed lower body mass index (BMI) in coffee consumers, compared with individuals who don’t consume coffee. Coffee may reduce appetite and dietary intake.

Greek researchers at Harokopio University, Athens, conducted a crossover study to evaluate the effects of caffeinated coffee on appetite and dietary intake. Sixteen normal weight and 17 overweight/obese habitual coffee consumers (at least one cup of coffee/day) were enrolled. Each participant took part in three trials at least one week apart. Participants were required to abstain from caffeine from 24 hours and then reported to the lab to consume a breakfast and 200mL of one of three experimental beverages: instant coffee with three mg caffeine /kg body weight (Coffee 3); instant coffee with six mg caffeine/kg (Coffee 6); or water. Participants had to consume the breakfast and the beverage within five minutes.

During a three-hour period following beverage consumption, appetite feelings and participants’ dietary intake the day before the experiment were assessed. After this three-hour period, participants were offered an ad libitum lunch buffet. The following day, participants reported by telephone their food and fluid intake for the rest of the experiment day.

Normal  weight participants consumed comparable energy in the ad libitum meal and in their total daily intake in the three interventions. However, among weight/obese individuals, Coffee 6 resulted in significantly reduced energy intake during the ad libitum meal, compared with both water and Coffee 3.

Doses used in this study for participants were somewhat staggering. The average caffeine content of the beverage in the Coffee 6 group equaled roughly four 8-ounce cups of brewed coffee. We need to be cautious about the use of this dosing in the clinical setting. But as part of comprehensive weight-management strategy, caffeinated coffee may be helpful for reducing energy intake.