It took me seconds to find credible information arguing against your assertion: "Using the model, we found that fatter individuals would indeed survive longer and, at a given body weight, females would survive longer than males, when totally starved"
A mathematical model of weight loss under total starvation: evidence against the thrifty-gene hypothesis
This isn't even arguing with what I said. I said at the point of starvation, being obese is only going to let you live for a few more days longer than a skinny person assuming you dont get any more food until death.
This paper is arguing that they are more likely to survive in general, which is obvious.
A mathematical model of weight loss under total starvation: evidence against the thrifty-gene hypothesis
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3529354/