On the show the researchers tested two women who were good friends and knew each other well. One was about 20 lbs underweight (we'll call her the skinny one), the other was about 20 lbs overweight (we'll call her the chubby one).
They both swore that the skinny one ate loads, while the chubby one hardly ate a thing. The women were convinced that the difference in their weights was due to the skinny one having a fast metabolism, the chubby one having a slow metabolism.
To test this out, the researchers measured the two women's oxygen consumption and CO2 output (to assess their base metabolic rate), and used an advanced urine analysis to measure their calorie consumption over the course of several days.
The results? Not only did the chubby woman have the faster metabolism (it takes extra energy to haul extra pounds around, so most fat people have quite a high metabolism). She also ate about 50% more calories per day than the skinny one.
Quite simply, her weight gain was nothing to do with her metabolism - she was simply eating too much!
So did the show offer any help or advice for those trying to lose weight? Actually there were a number of useful pieces of research.
