If I was really going on survivor, id learn how to hunt, fish, gather (generalised, or even specifically for the next location, as they often advertised, especially recognising nutrient containing foods and energy dense tubers), climb trees for honey and coconuts and make hunting weapons.
I mean, youd actually want a genuinely large amount of training. Courses like: Stone tool making, primitive weapon hunting, barefoot treeclimbing, some kinda bushlore course (either specific or generalised).
If you were skilled in these things , not only would you not go hungry, but youd be assured to be kept on till near the end because everyone would value the food.
None of the locations they are in, ever seem free of food (I mean, they are usually on fairly lush islands, once they were in africa), but more that the people on the show dont have the skills to get it (apart from some occasional fish). Ive never seen anyone dig up a tuber or root, or pick a leafy green. I beleive once I saw someone attempt some coconuts.
Has anyone ever taken down an animal apart from a caged chicken or some fish?
Oh, and id also study up nutrition, and select the food auction food based on what I lacked, rather than taste.
But your ideas aint bad either. Being in ketosis, might help, as would be replete with vits and minerals.
Ideally though, you wouldnt be short on food. it aint like they stage these things in the middle of a desert.
Id probably actually watch it, and it would be far more interesting, if there were a few people with genuine relevant survivalist skills on it.