that "no diet helps" your wife's friend, she very well may be the answer to the energy "crisis" because her thyroid is somehow fomenting a chemical reaction that is literally creating energy out of thin air.

Or, more likely, she eats a lot more than she thinks she does. Various scientific studies have found that people underestimate the number of calories they consume by an average of 25-30% and most overestimate the calories that they burn. That's how so many people think they are eating at a rate that should result in weight loss, but still gain. I've witnessed this phenomenon with family members, friends, and even myself on occasion.