[USA]

Here are the numbers for boneless skinless raw chicken breast when run through the calculator

Crude Protein 23%
Crude Fat 1%
Crude Fiber 0%
Moisture 75%
Ash 1%

Nutrients on Calorie Basis
Total Protein 89.9%
Total Fat 10.1%
Total Carbohydrate 0.0%

As you can see the numbers for a high moisture, high protein, low fat meat will NOT have a super high fat content. So it is unrelated to “the difference between the calorie basis versus dry matter basis.” The high fat is only related to the fat content of the meat they use in canned products.