Now proven scientifically. Take, for instance, sleep. Nobody ever doubted that sleep was a necessity, but now I have scientific evidence to back me up when I’m caught napping in the middle of the day. I’m sleeping to stay fit, of course! They say, and I quote:

Even two or three nights of shortened sleep can have quite significant effects, he says, disrupting the normal hormonal balance and making more likely a series of long-term consequences, including obesity, diabetes, and heart disease. [...]

For adolescents, he suggests allowing them to sleep in at weekends, but not for more than two to three hours, as that can disrupt the normal rhythms.

And I drink to increase my income, if this little bit of research is to be believed. According to the authors,

“Drinkers may be able to socialize more with clients and co-workers, giving drinkers an advantage in important relationships,” the researchers said. “Drinking may also provide individuals with opportunities to learn people, business, and social skills.”

Update:
And chocolate! How can I forget chocolate! Though I do think that the term flavonoids seems more marketing-speak than genuine scientific terminology. But I’m no expert — I’m biting into this delectable delicacies purely on medical advice.

The fourth and final thing that’s good for everyone needs no scientific evidence, really. ;-)