Consider the following potential conclusion from Supersize Me: Eating fast food and avoiding exercise for 30 days causes a 13% weight gain, bouts of depression, and a reduced sex drive. From a...

Consider the following potential conclusion from Supersize Me: Eating fast food and avoiding exercise for 30 days causes a 13% weight gain, bouts of depression, and a reduced sex drive. From a research standpoint, why would this conclusion be inappropriate?