Canned foods are over-counted by eye. 50–200% error in visual estimation (Almiron-Roig et al., Appetite 2013). Per 100 g drained: 116 kcal, 26 g protein, 247 mg sodium. Weigh after draining — the tin's labelled net weight is often wet.
How should I track Tuna, canned in water?
Tuna, canned in water is high in protein. For the most accurate tracking of Tuna, canned in water, weigh it raw and boneless. Fish loses 15–25% of its weight during cooking as water evaporates (USDA cooking yield data). If you are using canned fish, the drained weight is what matters — the difference between oil-packed and water-packed can be 40–80 calories per can. A quick drain-and-weigh habit saves you from hidden calories. Also keep in mind that smoked or cured fish has different values than fresh due to moisture loss and added salt.