Coffee on its own has almost no calories. It's what we pour in that counts. And a new study from Tufts University in Boston shows that what we pour in has quietly changed.
The study
Researchers at Tufts' Friedman School of Nutrition looked at a big US government health survey called NHANES. They used eight rounds of it, from 2003 to 2018, covering about 30,000 adults aged 20 and over. Each person described, in detail, everything they ate and drank on two separate days. The results were published in October 2026 in the Journal of the Academy of Nutrition and Dietetics.
Same coffee, more calories
Here's the odd part. The amount of coffee people drank barely moved: about 13 ounces a day, roughly 380 ml, a big mug and a bit. But the calories from coffee went up from 43 to 60 a day. That's nearly 40% more, without drinking a single extra cup.
Meet the villain: creamer
You'd guess sugar. Wrong. Sugar and normal milk stayed about the same since 2003. The thing that grew was non-dairy creamer, the powdered or liquid stuff that whitens coffee without being milk.
By weight, plain dairy milk is still what Americans add most: 21.4 grams a day in 2018, against 8.1 grams of creamer and 4.4 grams of sugar. But a gram of creamer brings a lot more calories than a gram of milk. That's the whole trick.
In 2003, creamer added 7.71 calories a day. By 2018 it added 18.5, more than sugar (16) or dairy milk (11). "Non-dairy creamer being added to coffee has now passed both sugar and dairy," said the lead author, Yongyi Pan.
Why does it pack so many calories? "Non-dairy creamers can be high in saturated fat, which is calorie dense," Pan explained. Plant-based milks grew too, from almost nothing to 2.45 grams a day, but they're a much smaller part of the story. Pan says creamer has become popular "as consumers seek plant-based or dairy alternatives".
Plot twist for anyone who chose creamer to be healthier: "non-dairy" doesn't mean light. Sometimes it's the opposite.
Who drinks the most
People who slept fewer hours and people who worked longer hours drank more coffee. No surprise there. Coffee intake was similar whether people's overall diet was good or bad. Coffee doesn't judge.
Is 17 calories a big deal?
On one day, no. It's a biscuit bite. But 17 extra calories every day for a year is over 6,000 calories, and the study is about averages: heavy coffee drinkers with lots of creamer get far more. The senior author, Fang Fang Zhang, points out that coffee "is often accompanied by the addition of sugar and cream," which brings added sugar and saturated fat with it.
One honest limit: people reported what they ate from memory, and day-to-day diets vary, so there's some error in the numbers.
What it means for you
Keep the coffee. The research isn't against coffee at all. Just read the label on the creamer: check the saturated fat and the serving size, because "one splash" is rarely one serving. Plain milk, a smaller pour, or a creamer with less fat are easy swaps.
Your coffee doesn't have to be black. It just doesn't have to be dessert either.