LOL
\\\\My main stumbling block is portion sizes and encouragement to follow my wife's unhealthy ways! \\\\
Truth be known, that is the commonest cause of diet related illnesses today...diabetes, high BP and heart disease.
About your question: it is how you want to live the rest of your life.
If eating a "healthy diet" (whatever that is) makes you feel satisfied physically and emotionally , then go ahead, you have got it made.
However if your final years are spent counting the calories and "watching " what and how you eat and day after day is a fight with your conscience about what you are eating........then forget it.
So really I cannot answer your question except to say that even at 70 that "healthy diet" can prolong your life.............if you want it prolonging.