Hi #83873,
interesting thoughts.
There is a paradox here though, in the sense that overweight people (who appear to be well-nourished) CAN be suffering from malnutrition or undernutrition; surfeit fat reserves do not necessarily add up to adequate food reserves on a fast. It has been shown time and again that a thin person can sometimes fast more safely (and for longer periods of time) than a fat person, if their pre-fast diet of some months/years standing has been of a highly nutritional character. The documentary "Supersize Me" has been adequate proof of this.
You are quite right though #83873, pollution is everywhere, and by all accounts becoming worse with the passage of time. However, water-fasting according to thirst remains the best and only method employed by Nature to heal and cleanse in the most effective and efficient way possible.