Leptin - So far this looks to be more of an anti-starvation hormone. The fact that it is highly elevated in obese people is irrelevant, probably due to the fact that receptor levels are saturated.
However, problems occur when Leptin is low, although it does not seem to affect percieved hunger it does have an effect of sex hormones and depression.
Ghrelin - It seems to this hormone is also not completely involved in hunger and apetite.
http://www.ncbi.nlm.nih.gov/pubmed/16014402 - The satiating effect of dietary protein is unrelated to postprandial ghrelin secretion.
Leptin production is mainly regulated by insulin-induced changes of adipocyte metabolism - http://www.ncbi.nlm.nih.gov/pubmed/11790963
I also found another eye opening study here - http://www.ncbi.nlm.nih.gov/pubmed/12679444
Despite cutting out 95% of bypass patients stomach's, levels of circulating ghrelin remained in measurable quantities.