Step One: Create a ridiculous hypothesis and treat it as if it were a law set in stone. You're guaranteed success if you somehow include the word "obesity" and plays on people's fear of becoming fat.
Step Two: Don't bother to do any actual scientific work; borrow data from someone else's study.
Step Three: Take the data and manipulate the living hell out of it until it somewhat resembles your goal.
Step Four: Create a computer animation of your twisted data that doesn't actually resemble the hypothesis, but have a voice-over that claims it does. People will just see a bunch of dots and take your word for it as long as you're heavy on the fat scaremongering.
Step Five: Toss out "correlation is not causation", because it doesn't benefit your conclusions. Directly blame fat people for something, and spread it on thick.
Step Six: When someone challenges you, make up some b.s. that counters it. Even if your b.s. directly contradicts the b.s. you used to answer the last question
Step Seven: Profit! Fame! And, as an added bonus, people start shunning their fat friends all because of you, perpetuating fat hatred--that'll teach those fatties to stop eating! You just cured "obesity"! Aren't you awesome?