What does the phrase "to weigh every bit of" mean?

[Teo]

This tuna appeared to weigh every bit of 150 pounds.
Does the phrase “to weigh every bit of” mean “to weigh as much as”?

[Luschen]

Sort of, it means “to weigh at least” and perhaps even more. So the tuna looked like it weighed at least 150 pounds, and perhaps even more.