usually we'd do a yeah nah, as an optimized "I hear what you are saying, but that's not true... < inform the person of the truth >" as in "You're looking well"

usually we'd do a yeah nah, as an optimized "I hear what you are saying, but that's not true... < inform the person of the truth >" as in "You're looking well", "yeah, nah, been a bit crook lately"