Could Fluoride be linked to Obesity?

This is an interesting discussion on the problems of low thyroid activity. Whilst he does not link it to fluoride, as fluoride is found in research to adversely affect the thyroid and the pituitary, both mentioned in the article, then this could be a major cause of obesity. See: http://www.drbriffa.com/blog/2008/04/04/low-thyroid-function-may-be-a
So Fluoride could be a factor-in-weight-gain-despite-normal-tests.
Highly fluoridated places like the USA are known to have major obesity problems, but the tendency so far has been to blame junk food and over-eating. Whilst this may well play a part, why does the body demand lots of food, but then not use it?
It would be a plausible theory that the body knows that it is short in certain nutrients, so hunger is created, but the thyroid under-activity means that the body does not use this food before a separate mechanism puts the extra to fat.
This leaves the body still short of nutrients, so still hungry (or rapidly hungry again), but not using the food quickly enough when it is eaten so more and more goes to fat. The fact that the food may be junk food contributes to this negative cycle, but the fluoride poisoning may be an equally important effect.