Coffee Drinkers Have Less Body Fat, More Muscle and a Distinct Hormone Pattern, Finnish Study Finds

People who drink more coffee tend to have healthier body composition and distinct hormone patterns, according to a new study from the University of Oulu in Finland. Researchers analyzed data from 2,264 people, all 46 years old, who are part of the Northern Finland Birth Cohort 1966, examining how their usual coffee intake related to metabolism, cardiometabolic risk markers and sex hormone levels.

Participants who drank more coffee had lower total and visceral body fat and greater skeletal muscle mass, even though their body mass index (BMI) was similar to that of lighter coffee drinkers. Higher coffee intake was also linked to lower levels of branched-chain amino acids in both men and women; when chronically elevated, these amino acids have previously been associated with insulin resistance and a higher risk of type 2 diabetes.

The clearest hormone differences appeared in men, where greater coffee consumption was associated with a more favorable glucose-insulin profile, higher total and bioavailable testosterone, and higher sex hormone-binding globulin (SHBG), though free testosterone was modestly lower. In women, higher coffee intake was mainly linked to increased SHBG and lower measures of free androgens.

"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, the study's lead author and a doctoral researcher at the University of Oulu. Because the research was observational, it cannot establish that coffee directly caused the differences. Finland has one of the highest coffee-consumption rates in the world, at about 11.8 kilograms per person a year, and the study was published in the European Journal of Nutrition.