How Many Calories Are in a Can of Tuna?

A standard can (about 80 grams drained) of water-packed tuna comes to roughly 90 calories. The figure shifts noticeably depending on whether the tuna was canned in oil or in water. Oil-packed tuna, even drained, can run up to 150-170 calories for the same weight because the fish absorbs oil as it sits; that's nearly a 2x difference from the water-packed version. How does draining liquid affect calories? Draining the can fully, especially with oil-packed tuna, makes a real dent in the total. An undrained can can carry almost 30% more calories than a drained one, since the absorbed oil or brine adds to the weight. Brine-packed tuna is usually the lowest-calorie option; the salt content is high, but with no added oil the energy value stays close to the water-packed version. What is the protein-to-fat balance in tuna? One can of tuna contains about 20 grams of protein, a high ratio for its calorie range compared with most other foods. That's why tuna is a popular pick for a low-calorie but filling protein source. Fat content can range from under 1 gram to about 10 grams depending on the type of can; checking the label's fat figure is the most practical way to choose between versions. How does tuna compare with other canned fish? Canned sardines and mackerel usually run higher in calories than tuna, since those fish naturally carry more fat to begin with. Canned salmon falls between those 2 fish types. A can of tuna stirred into a salad or sandwich can easily multiply the total calories by 2 depending on how much mayonnaise goes on top — the fish itself stays low-calorie, but the dressing is what really decides the total. What should you check on the label? Can labels usually list calories per 100 grams rather than per whole can, so working out the real portion means knowing the drained net weight. The label states both the pre-drain and post-drain weight separately, and it's worth not mixing the two up. Some brands sell the same can in both oil-packed and water-packed versions; the price gap on the shelf is small, but the calorie gap is large, so it's worth making a habit of checking the label. How should canned tuna be stored? An unopened can keeps well in a cool, dry cupboard for a long stretch, and its calories stay practically unchanged over that time. Once opened, refrigerate leftover tuna and use it within 3 to 4 days. It can stay in the can, but transferring it to a covered glass or plastic container keeps its flavor and quality better. If a can is bulging, dented or rusted, its contents aren't in a state worth calculating calories for; a can like that should be thrown out unopened, since those signs point to serious spoilage.