My thoughts:
I think that ALL BP meds that are effective over the long haul will cause weight gain if no other changes are made.
The logic is that high blood pressure takes extra calories to maintain; with the converse being that a pump needs less energy to pump against a low head of pressure.
Relax the heart's output and you have calories to spare (or to SPARE TIRE.

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The effect is probably the strongest with the drugs that additionally lower heart rate directly like beta blockers but many people show a lowered heart rate from ACEI and ARB classes also.