For sure, my sleep doc and I definitely discussed that and it's part of the plan. However, my dad also has obstructive apnea, and he is very much normal weight. He even had apnea surgery, and it didn't help at all. At my physical exam, the sleep doc said I had a large tongue which contributed (haha).
Assuming your dad is an American, I have to ask, is he a "normal weight" or his he "healthy weight?"
74% of adult males in the US are overweight or obese[1], which would make it the norm.
The vast majority of the time that I hear someone talk about "normal weight" they are referring to the average US weight, not the NIH definition. For example, I'm regularly called a "skeleton" or "beanpole."
At 6' and 155lbs I fall in to the "NIH normal," but far below the "US normal."
Were you referring to the NIH normal, or the US normal?