The New York City Department of Health (Hype), whose 2009 anti-soda PSAs played fast and loose with nutrition science, is once again straining credulity with another campaign of taxpayer-funded propaganda. Starting this week, New York City subway riders will see images of a diabetic amputee and a woman driving a mobility scooter with the message that increasing portion sizes, not any other lifestyle changes, are driving rising obesity and diabetes rates. Here’s one example:

 

Commissioner Thomas Farley claimed that his Department “really felt [it] need to drive home a point that large portions are not completely benign.” Of course, nobody is claiming that overeating is healthy, and given that the CDC found that total dietary energy intake didn’t change significantly from 1998 to 2008, perhaps consumers have heard the point. Likewise, Gallup found that obesity fell during 2011. Both of those developments happened without a government line-inspector looking over every cook’s shoulder or a government anti-refill gendarme keeping people away from the soda machine.

Weight gain is a function of simple mathematics: calories in exceed calories out. Of course, the food scolds concentrate on only one side of the balance (calories in). The PSAs ignore the non-dietary lifestyle contributors to obesity (such as longer driving commutes), to say nothing of the beneficial effects of exercise on both obesity and diabetes management. Whether you have a big portion or not, what matters is that you balance it out. Just ask Michael Phelps.

Of course, the message of the PSAs is so over-simplified that the possibilities for extending the logic to absurd levels are nearly endless. Yes, portion sizes and obesity rates rose more or less together, but correlation does not prove causation, and upward-sloping lines convey no useful information. It’s so ridiculous, we couldn’t help but offer a few ideas to the Big Apple for its next “public service” campaign:

But of course that’s the point: These posters are pure propaganda. If consumed in reasonable quantities, drinking soda will not lead to amputation. Likewise, eating the occasional cheeseburger—yes, even a big one—will not condemn a poor, benighted soul to life in an obesity scooter. Tarring certain foods and making outlandish implications will not make New Yorkers any healthier.