Are these the conditions that signal the fall of a civilization?

Obesity was not an epidemic in Greece or Rome. Only the wealthiest of the population could afford to eat like that. Homosexuality exists in all civilizations and a false sense of security comes and goes in most civilizations. If you really want to draw parallels to America or other modern industrialized civilizations, you might want to focus on deficit financing of war, continuous military presence spread out over several foreign countries, an influx of immigrants that Balkanizes the population, and increasing political and class division within the population.