Can you lose weight by just eating tuna and drinking water?
You would lose weight. However, this is an unhealthy way of losing weight and it might affect your body negatively. Your internal organs will particularly be affected. It's best to lose weight while still maintaining a healthy diet.
Yeah, but it would be unhealthy. You need other nutrients in your body than the protein that tuna gives.
It doesn't work for sharks so why should it for you"