other than the shakes and tabs, is all the food in these meals "free" for you on the ship?
All food is free for the crew on the ship, right now I'm on vacation, which is why I'm free to train twice a day, on the ship the don't have sweet potato for the crew, sometimes they have baked or mashed, but they always have rice, white and brown, so on the ship I eat rice as my staple carb, I also have access to salmon and steak all the time due to having friends that are chefs in the main dinning galley, which have to make mass quantities of food to provide to our 3000 passengers, theres always a bunch left over and they'll leave a few for me, because again they aren't feeding the crew salmon or steak.
you already have everything going for you, why add heart attack to the list 
My heart is in excellent shape, I just went in for a complete work up, I get all blood work done every vacation, just to make sure all is well, this time I asked my GP to make a referral to see a cardiologist, just because I wanted to make sure all is OK there, I got everything done, EKG, Ectocardiogram, 24 hour heart monitor, a bunch of stuff done, everything is excellent there, I do have a slightly enlarged heart but the doc said that's completely normal for anyone who does athletics and trains intensely.