There could be a link, but I wouldn't bet money on it. When I've seen extreme couponers and uber-frugal people on shows like Oprah, and in women's magazines, those women were all very thin and professional looking.

The only extreme bargain-a-holic/food hoarders I've known personally have been thin men.

I suspect that this show may be cherry-picking the folks who look the sickest, strangest, and most pitiful.

Then of course, there's also the coincidence and cultural factors.

Coincidence: 2/3 of Americans are overweight, and 1/3 obese, so just coincidence could account for the large number of obese folks on the show.

Cultural/economic factors: In the USA and in many other countries, obesity is inversely proportional to income. The poorest are the most obese, and I would guess that extreme couponing is also tied inversely to income. The more people need to save money, the more likely they are to be drawn to frugal methods including couponing.

I wouldn't be surprised if there was a link, I just wouldn't assume there is one, or that if it is, it's necessarily tied to the fact that couponing is rarely for healthy food. I suspect it's a factor, but I also suspect that tv shows exploit the folks they're profiling, looking for the most disturbing and shocking people to showcase.