What could explain a man with low protein intake having an albumin level of 5.5g/dL?

An albumin level of 5.5 g/dL is considered high, and this can be explained in the context of dehydration. Dehydration can lead to a concentration of proteins in the blood due to a reduction in plasma volume, which in turn elevates the level of albumin as a result of hemoconcentration. While low protein intake typically results in low albumin levels, dehydration alters the plasma volume and can create a misleadingly elevated albumin reading.

High physical activity could also affect overall protein metabolism and hydration status, but it does not directly lead to an elevated albumin level in the same way dehydration does. Chronic liver disease typically presents with low albumin levels due to impaired production, and iron deficiency generally does not have a direct impact on albumin concentration. Therefore, dehydration is the most plausible explanation for a man with low protein intake presenting with an elevated albumin level.