Adults who drank at least five cups of coffee a day had less visceral fat, lower overall body fat and greater muscle mass than non-coffee drinkers in a Finnish study, though researchers cautioned that the findings do not prove coffee caused the differences.
By yourNEWS Media Newsroom.
People who regularly drink five or more cups of coffee a day may have a leaner body composition than those who avoid the beverage, according to research examining more than 2,200 middle-aged adults in Finland.
The study, published in the European Journal of Nutrition, found that the heaviest coffee drinkers carried less visceral fat and had more muscle mass even though their body mass index was essentially the same as participants who consumed little or no coffee.
Researchers from the University of Oulu analyzed 2,264 members of the Northern Finland Birth Cohort 1966. Participants were 46 years old when the measurements used in the analysis were collected.
“Coffee is consumed by millions of people every day, yet we still know surprisingly little about how it relates to our metabolism and hormones,” said Luca Verroest, a doctoral researcher at the University of Oulu and the study’s lead author.
Participants were divided into four groups according to their self-reported coffee consumption, ranging from no coffee to five or more cups per day.
Researchers assessed weight, body mass index, waist circumference, body fat percentage, muscle mass and blood pressure. Blood samples were also used to examine cholesterol, insulin, amino acids and sex hormone levels.
The differences were most pronounced among those reporting the highest coffee consumption.
Participants drinking five or more cups each day had an average body fat percentage of approximately 27%, compared with about 29% among people who did not drink coffee. The highest-consumption group also had approximately 6% less visceral fat and the greatest amount of muscle mass.
Visceral fat is stored deep within the abdominal cavity around internal organs. Unlike fat located immediately beneath the skin, excessive visceral fat has been associated with increased risks of several chronic diseases, including heart disease, Type 2 diabetes, Alzheimer’s disease and some cancers.
Despite those body-composition differences, researchers found little difference in BMI across the coffee-consumption groups.
That distinction is significant because BMI reflects weight relative to height but does not distinguish between fat and muscle or reveal where fat is stored. Two people can therefore have similar BMI measurements while having substantially different amounts of muscle and visceral fat.
Verroest said the pattern remained evident after researchers accounted for other variables.
The findings showed “a distinct pattern that didn’t disappear even after we took into account body mass index (BMI) and lifestyle factors,” Verroest said.
Researchers also identified metabolic and hormonal differences among habitual coffee drinkers.
Higher coffee intake was associated with lower concentrations of an amino acid that previous research has linked to obesity and Type 2 diabetes. Among male participants, heavier coffee consumption was generally associated with more favorable insulin levels and higher total testosterone.
Men consuming more coffee nevertheless had lower levels of free testosterone, according to the researchers.
Previous research has examined relationships among sex hormones, insulin, adiposity and risk factors for myocardial infarction in men, reflecting the complicated interaction between hormone levels, metabolism and body composition.
The study’s authors said the observed hormonal and amino acid differences could potentially have implications for metabolic disease, but emphasized that their research establishes associations rather than demonstrating that coffee directly causes those changes.
That limitation is particularly important because the study was observational.
Researchers did not assign participants to drink different quantities of coffee and then monitor the resulting biological changes. Instead, they compared existing coffee-drinking habits with measurements of body composition and metabolic markers.
The analysis therefore cannot determine whether coffee itself produced the lower visceral fat and higher muscle mass seen among heavier consumers.
Researchers also could not establish which components of coffee might be responsible for the associations.
Coffee contains numerous biologically active compounds, including polyphenols, while caffeinated varieties also contain caffeine. The study could not determine whether the observed differences were associated primarily with caffeine, polyphenols, another component of coffee or other characteristics shared by habitual coffee drinkers.
Polyphenols are naturally occurring plant compounds found in beverages including coffee and tea. Other research has examined how gut microbes metabolize compounds such as the catechins found in green tea, including through processes involving C-ring opening and galloyl ester hydrolysis.
The Finnish findings also join a broader body of research examining possible relationships between coffee consumption and long-term health.
A separate 2026 study involving more than 350,000 adults found that consuming five or more cups of coffee a day was associated with a 47% lower likelihood of developing liver cancer. The association was also reported among people drinking decaffeinated coffee, suggesting that compounds other than caffeine could contribute to some of coffee’s observed health associations.
Coffee consumption, however, is not without potential drawbacks.
Unfiltered preparations such as French press coffee have been shown to increase LDL cholesterol. High doses of caffeine can also produce significant cardiovascular effects in susceptible individuals, including sudden increases in blood pressure and abnormal heart rhythms. At very high levels, caffeine overstimulation has been associated with severe cardiac complications, including cardiac arrest, even among otherwise healthy adults.
Individual tolerance therefore remains an important consideration, particularly when interpreting findings involving consumption of five or more cups per day.
The study does not establish that people should begin drinking that amount of coffee to reduce abdominal fat or increase muscle.
Instead, researchers concluded that habitual coffee drinking was associated with a “leaner body composition” and said additional research would be required before the findings could be translated into dietary recommendations.
The results come amid broader concern over obesity and metabolic health.
Federal data previously cited in reporting on obesity showed that 71.6% of the U.S. population was overweight or obese in 2015-2016, with the proportion reaching 74% by 2022.
Body weight alone, however, does not provide a complete picture of metabolic health. Researchers have increasingly examined where fat is stored, how much lean muscle a person carries and how diet affects metabolic markers over time.
A 23-year study involving approximately 2,000 participants, for example, found that the quality of food choices can be as important as calorie intake when assessing cardiometabolic health.
Other research has reported an inverse relationship between fruit and vegetable consumption and the amount of visceral and liver fat, reinforcing the role that broader dietary patterns may play in determining body composition.
Coffee has also been extensively studied in connection with exercise performance and weight management, making the Finnish findings part of a larger effort to determine how one of the world’s most commonly consumed beverages may interact with metabolism.
The University of Oulu researchers cautioned that their results remain preliminary in terms of dietary guidance.
Although people consuming the most coffee tended to have less visceral fat and more muscle than non-drinkers, the study cannot establish that increasing coffee intake will produce those outcomes in an individual.
Further research will be needed to determine whether coffee itself influences body composition, which compounds might be responsible and whether the apparent metabolic benefits persist across different populations and levels of consumption.
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