Are stents like bypass? It sounds like you are on the right track for yourself. Maybe if our fingerprints are unique to our bodies, nutritional needs are too.
I use olive oil. Last summer, I gained 6 lbs in a week. Losing weight wasn't my goal, but since it was gone, I didn't want it back. I thought over in my mind what I was doing differently. I was trying to use up a bottle of vegetable oil, maybe canola, and had switched away from the olive oil. It turns out, at least according to Google, and my scale, that some veg oils can cause weight gain. so I got rid of the canola and the 6 lbs. I use butter, too, but sparingly. I don't use a lot of sugar, and I really like Monk's Fruit, if I want a sweet treat. Gotta watch the triglycerides, too. I read that they affect the cholesterol in your body. I have cinnamon in my coffee every morning, which is supposed to help with high bp, and lowering blood sugar. I eat an avocado almost every day, which is supposed to be a long-term aid for lowering cholesterol. Even if it didn't, I'd eat avocado as often as I can
I've avoided red meat, except for an occasional treat. I make a 1 lb meat loaf about once a month, and make it last 3 or 4 meals.
Since Oct. 2019, I changed my diet, and unexpectedly lost weight and it stayed off. Thought I was following in my Mom and Gram's footsteps, as they both lost weight when they got older. But no, not there yet :/ This year, I've gained weight back. Guess in the battle of the bulge, I have to be ever vigilant!