Exaggeration is ultimately counterproductive

When I teach stats, we discuss a bit how numbers can be used to deliver alarmist messages. Using a generic Compound X that shows no toxic effects up to 100 units with single digit baseline levels, we discuss how varying increases in X might be reported.  So let's say baseline levels of X are 2 units.  Something is done, and levels of X rise to 3 units and this change reaches the level of statistical significance.  The alarmist reporting that gives the greatest impact would probably be to state something like:  "levels of X increased by 50%".  This is true, and it sounds daunting taken out of context.  Alternately you might see something like "levels of X were 1.5 times baseline", though I think the 50% number has more impact.  For anything less than 10X increase, the alarmist reporting almost always uses the percents, because over 100% has emotional intuitive impact.  So for example if X values rose to 4 units, "X values doubled" has impact, but "increased by 100%" or even "were 200% of baseline" sound worse.  And let's' say the levels of X increased to 10 units.  Yeah "five times" sounds less dramatic than "500% of baseline" or "increased 400%", and definitely more dramatic than just presenting it as an "8 unit increase".   The reporter of such information trying to exaggerate the impact to drive an agenda does not tell the consumer of the information about X's safety threshold.  And chances this is not common knowledge this information consumer possesses.   But I contend that reporting data in this way is misleading.  If it's just some detergent manufacturer boasting stain removal or something like that, who really cares ... but if it's a scientist looking to influence public policy and regulation?  

So this landed in the old Inbox yesterday.    For the slightly vision impaired, the text reads:  

Portion sizes have been growing.  So have we.  The average restaurant meal today is more than four times larger than in the 1950s.  And adults are, on average, 26 pounds heavier.  If we want to eat healthy, there are things we can do for ourselves and our community.  Order the smaller meals on the menu, split a meal with a friend, or, eat half and take the rest home.  We can also ask the managers at our favorite restaurants to offer smaller meals.

This is put out by, as you can see, the CDC.  Now, no doubt we are eating more, but the "NOW" values reflecting "the average restaurant meal" are exaggerated -- apparently for effect and to drive an agenda.  The reason this landed in the Inbox was that the person who sent it to me said that those sizes seemed out of whack.  Perhaps indicative of large-sized meal, but average?  I concur!  They are so ridiculous as to render this "infographic" a "DISinfographic".  Let's use McD's to illustrate, a PDF of nutritional info for popular items can be found here.  

• The Burger:  Burger weights include the bun, but the only burger on the menu approaching 12 oz. is the Angus Deluxe at 11.2 oz.  Your Big Mac is only 7.5 oz, Quarterpounder w/cheese 7 oz, and the double QP w/cheese comes in under 10 at 9.8 oz (so a quarter pound uncooked patty weighs at most 2.3 oz).  Burger is blatant exaggeration to the point of deceit.  
• Fries:  A large fries is 5.4 oz.   Therefore representing the "average" portion of fries as 6.9 oz is a blatant exaggeration to the point of deceit.
• Soda:  McD's sodas are the following sizes:  Small = 16 oz, Medium = 21 oz, Large = 32 oz  (Child = 12 oz).  Now, you can argue that these are too large and you won't get any argument from me, but representing the "average" soda portion as 42 oz is over-the-top blatant exaggeration to the point of deceit.

I don't know how many of you need the CDC to simplify your health information for you  -- I note they didn't mention just preparing meals at home as an option -- but I found the last line of the disinfographic to be most absurd: Ask the managers to serve smaller portions?  Only in America folks, do we encourage consumers to get less of anything and inevitably pay more per unit for it.  But let's see.  Is there anything stopping anyone from replicating that 1950's meal there?   The only item you can't get in the small size is the soda, but most of the time you're not even paying for the soda.  By that I mean that combo meals usually come with a small or medium soda for pennies more than the burger and fries.  There is NOTHING forcing anyone to get the sugary soda vs. just water, and there's nothing forcing you to fill the cup to the brim at the fountain or drink the whole thing if it's been dispensed for you!   As for the rest of the meal, a regular hamburger or cheeseburger is right there on the menu, and small fries (at 2.4 oz) too.

The exaggeration, however, is the focus of my rant today.  The CDC loses it's credibility for making whatever point it is they're trying to make to effect lifestyle changes in the public.   They've just wasted countless taxpayer dollars to create something so ridiculously exaggerated as to be a laughing stock.

Now ... from what other sources of dietary information are we treated to similar behavior?  I could give examples.  I'm sure you don't need me too.  :D