Guides
Does Coffee Make You Gain Weight?
A study of 2,264 Finnish adults links heavier coffee drinking to less visceral fat, more muscle and a different hormone profile.
Guides6 min readUpdated October 15, 2026
Guides
A study of 2,264 Finnish adults links heavier coffee drinking to less visceral fat, more muscle and a different hormone profile.
The question of whether coffee makes you gain weight comes back every few years, usually with a headline. A study published in July 2026 in the European Journal of Nutrition offers something more useful than a verdict. It measured body composition, metabolism and sex hormones in 2,264 adults, all born in the same year and measured at the same age. It describes a link. It does not show that coffee causes anything.
What makes the study worth reading closely is what was measured, and which coffee the participants actually drank.
The participants come from the Northern Finland Birth Cohort 1966, a group of people born in that year and followed since. The analysis used data collected when they were 46, and 47 percent of the sample were men.
Coffee intake was self reported in a postal questionnaire, recorded in cups per day with no set cup size. Body fat, visceral fat area (the fat around the abdominal organs) and skeletal muscle mass were estimated using bioimpedance. Blood was analyzed for metabolites, glucose and insulin markers, and sex hormones. The models adjusted for BMI, education, smoking, physical activity and alcohol, and were run separately for men and women.
| Coffee intake | Participants |
|---|---|
| None | 70 |
| 1 to 2 cups a day | 296 |
| 3 to 4 cups a day | 822 |
| 5 or more cups a day | 1,076 |
The spread of the groups is worth noticing on its own. In a country that drinks as much coffee as Finland, the heaviest group was the largest by a wide margin, and only 70 people drank none. That shape tells you a lot about how the results should be read.
The groups drinking more coffee had a lower body fat percentage, less visceral fat and more skeletal muscle mass. Their BMI, though, was similar across groups. That gap is the interesting part: what differed was not how much these people weighed so much as how that weight was distributed.
Plain coffee contributes almost nothing; the rest of the routine does.
In the blood, higher coffee intake was linked to lower levels of branched chain amino acids in both sexes. When those amino acids stay high over time, they are linked to insulin resistance and to type 2 diabetes risk, a relationship we cover in our guide to coffee and type 2 diabetes. Among men, heavier coffee intake also went with a better glucose and insulin profile.
The hormone results are the most striking part of the paper. In the adjusted models, each extra daily cup went with the changes below.
| Marker | Men | Women |
|---|---|---|
| Total testosterone | Slightly higher, +0.29 nmol/L | No link |
| Bioavailable testosterone | Higher, +0.08 nmol/L | Not reported |
| SHBG | Higher, +0.57 nmol/L | Higher, +1.27 nmol/L |
| Free testosterone and free androgen index | Slightly lower | Free androgens slightly lower |
SHBG is the protein that carries sex hormones through the blood, and it rose in both sexes. The lead author, Luca Verroest, described the pattern in the university's press release as a distinct hormone signature that held after adjusting for BMI and lifestyle. That is a fair description of what the models show. It is also the kind of result people tend to read too much into, which is why the next section matters more than this one.
The authors are clear about the limits, and they are substantial.
The study population drank almost exclusively filtered coffee.
None of that makes the study worthless. It makes it a description of a group of people at one point in time, which is what an observational cohort is.
The reasonable reading is reassuring rather than remarkable. In this group, drinking a lot of coffee was not linked to more body fat. It was linked to less of it, along with more muscle and a different hormone profile.
That does not turn coffee into a weight management tool, and it is not a reason to move to five cups a day. What it does is weaken the idea that regular coffee drinking is quietly causing fat gain in the people who drink it most.
It is also worth remembering where the calories actually come from in a coffee habit. Black coffee on its own contains almost nothing. If a coffee routine contributes to weight gain, it is almost always the sugar, syrups and large amounts of milk added to it rather than the coffee itself. And tolerance to caffeine varies from person to person, partly for genetic reasons, which is one reason a dose that suits one person can leave another feeling overstimulated.
One detail in the paper deserves more attention than it usually gets. Among participants with data on the type of coffee they drank, 97.8 percent drank filtered coffee, with more than one answer allowed: 13.5 percent also mentioned boiled coffee and 3.1 percent cappuccino.
That matters because paper filtration reduces exposure to diterpenes, the group of compounds that includes cafestol, and the filter holds back much of it. A group drinking almost entirely filtered coffee is therefore not a study of espresso, capsules, or the sweetened milk drinks common in many cafes.
So the results cannot be applied to every coffee drink. The researchers are already running animal studies to test whether coffee causes these changes and which compounds might be responsible. That is the same open question that runs through the wider research: coffee is far more than caffeine, and working out what each compound does is the part still missing.
This study found the opposite link: heavier coffee drinkers had less body fat and more muscle, with similar BMI. That is a link in one group of people, not proof, and black coffee by itself has almost no calories. Sugar, syrups and large amounts of milk are what usually add up.
2,264 adults from the Northern Finland Birth Cohort 1966, all measured at age 46. Only 70 drank no coffee, while 1,076 drank five or more cups a day.
Each extra daily cup was linked to higher total and bioavailable testosterone and higher SHBG in men, and higher SHBG with slightly lower free androgens in women. The links were small and, like the rest of the study, cannot show cause.
Not directly. Almost all participants who reported a coffee type drank filtered coffee, which reduces diterpene exposure through the paper filter. Espresso, capsules and sweetened milk drinks were not what this group was mostly drinking.
No. The authors themselves call for intervention studies before any claim of cause, and the links were weak. The case for drinking coffee is enjoyment plus a reasonable body of evidence at moderate intake, not this single paper.
This article is general education and does not replace medical advice. If you have questions about your coffee intake, your weight or your hormone levels, discuss them with a clinician rather than changing your routine based on a single study.