Coffee is not a protein. It contains almost no protein at all. A standard 8-ounce cup of brewed black coffee has roughly 0.3 grams of protein, which is less than 1% of the daily recommended intake of 50 grams. By any nutritional measure, coffee is not a meaningful source of protein.
What Coffee Actually Contains
Black coffee is nearly calorie-free, typically clocking in at 2 to 5 calories per cup. Those few calories come from trace amounts of protein, fat, and carbohydrates, but the quantities are nutritionally insignificant. What coffee does deliver is caffeine (about 95 mg per cup), along with small amounts of potassium, magnesium, and niacin (vitamin B3). It also contains antioxidants, particularly a group of compounds that may help reduce inflammation. In fact, coffee is one of the largest sources of antioxidants in the average Western diet, not because it’s especially rich in them, but because people drink so much of it.
For the FDA to allow a food to be labeled a “good source” of any nutrient, that food must provide at least 10% of the daily recommended value per serving. To earn a “high” or “excellent source” label, it needs 20% or more. Coffee’s 0.3 grams of protein per cup is about 0.6% of the daily value. It doesn’t come close to qualifying as a protein source by any regulatory standard.
Why the Question Comes Up
Coffee beans are seeds, and like many seeds, they do contain some protein in their raw form. Unroasted green coffee beans are roughly 10 to 13% protein by weight. But brewing coffee extracts very little of that protein into the liquid. Most of it stays behind in the grounds you throw away. The roasting process also breaks down some of the proteins in the bean. So while the raw ingredient has a modest protein content, the drink you actually consume has almost none.
The question also surfaces because of the growing trend of adding protein powder to coffee. Proffee, as some call it, has become popular as a way to combine a caffeine boost with a protein hit. That’s a different thing entirely. The protein in those drinks comes from whey, collagen, or plant-based powder mixed in, not from the coffee itself.
Does Coffee Affect Protein Digestion?
If you’re drinking coffee alongside a protein-rich meal, there’s some good news. Both caffeinated and decaffeinated coffee stimulate the release of digestive enzymes that help break down nutrients, including protein. Caffeinated coffee appears to have a stronger effect. So a cup of coffee with your eggs or yogurt may actually support the early stages of digestion.
That said, evidence on whether caffeine meaningfully changes how much protein your body ultimately absorbs is limited. There’s no strong reason to think coffee blocks protein absorption, but there’s also no proof it enhances it in a way that matters for your overall nutrition. If you eat adequate protein throughout the day, your morning coffee isn’t going to interfere with that.
How Coffee Compares to Protein-Rich Foods
To put coffee’s protein content in perspective, here’s what common high-protein foods deliver per serving:
- One large egg: 6 grams of protein
- Greek yogurt (6 oz): 15 to 17 grams
- Chicken breast (3 oz): 26 grams
- Cup of milk: 8 grams
- Cup of black coffee: 0.3 grams
You would need to drink roughly 20 cups of black coffee to match the protein in a single egg. Coffee belongs in the same nutritional category as water or tea: a hydrating, low-calorie beverage, not a food that contributes to your macronutrient intake in any practical way.
Adding Milk or Cream Changes the Math
If you take your coffee with milk, you do add a small amount of protein. A tablespoon of whole milk contributes about 0.5 grams. A generous splash of 2 or 3 tablespoons brings you to 1 to 1.5 grams. A latte made with 8 ounces of milk adds roughly 8 grams, which starts to become nutritionally relevant. But that protein comes from the milk, not the coffee.
Plant-based milks vary widely. Soy milk is comparable to dairy in protein content (about 7 grams per cup), while almond and oat milks typically provide only 1 to 2 grams per cup. If protein is a priority in your coffee, dairy or soy milk are your best options among common additions.
Black coffee on its own, though, is essentially a zero-protein beverage. It has many qualities worth appreciating, but being a protein source isn’t one of them.