Obviously this person lives in the same house as you (or at least is at the home very frequently). You will only drive yourself crazy taking note of everything he eats, and if you are mentioning it to him frequently, the effect will most likely be that he will completely ignore you, or worse, go into hiding and overeat in secret. You cannot force this person to eat oatmeal, or skip the ice cream, but you can help out in other ways.
With that said, one thing I would recommend is to put Benefiber in EVERYTHING you cook. That stuff is amazing. It is tasteless, odorless, and has no texture whatsoever when properly dissolved. And it works. I specifically use Benefiber for just those reasons. I put it in my oatmeal, my grape juice, my spaghetti sauce, even in plain water-- anything you eat or drink, you can add it to. I do not have high cholesterol, but my triglycerides are a wee bit high, and the benefiber helps keep everything in check.
I also use
Udo’s oil when I remember to order it. (
nutrional info here). It is an omega oil supplement made from plants, not fish oil. It lasts longer than fish oil, and does not have that rancid fish taste. It can be used in salad dressings and other things you would use cold oil in. (Never heat it, though). And, as others have said, you can buy the cholesterol lowering spreads, too. They really do work, but you have to use it everyday.
I know you are worried about this person, but you really can do only so much. You cannot force him to be healthy, to eat right, or to exercise. You can only offer healthy alternatives to what he is currently doing. It is up to him to decide to become healthy. Do those things you can do (adding fiber to whatever you cook, stocking the pantry with healthy snacks, preparing healthy, well-balanced meals, etc) and pray that your family member chooses to live a healthy lifestyle.