Preventive Medicine Column

Dr. David L. Katz

After a rather considerable fuss- including, but not limited to: two discrete phases spanning months; two scientific advisory committees; open and closed meetings in Washington, DC; open testimony by experts and the generally opinionated alike; and written testimony by a wider array of stakeholders- a committee of the august Institute of Medicine has issued its report on front-of-pack nutrition guidance.  The committee’s recommendations are, in essence, to note calories on the front of packs, and to provide a scale to indicate the relative quantity of added sugar, sodium, saturated fat, and trans fat.  It is not clear whether all of these nutrients will be bundled together into that scale, or whether each will be scaled separately.  They suggest a numerical scale, ranging from 0 to 3.

I can only conclude the committee members shop for groceries somewhere very different from the rest of us.

Presumably, the committee mostly wanted to rein in the excesses and transgressions of food manufacturers who tend to emphasize the positive.   A product that is ‘low fat’ but high in sugar will shout out the former only.  A product that is, in reality, a concoction of mostly sugar and artificial colorings will call out the fact that it is ‘fortified with 11 essential vitamins and minerals!” and, according at least to a sonorous announcer, ‘part of a complete breakfast!’  Perhaps so- but what part?

The strength of the recommendation res­ides in its potential to constrain and unify such efforts by food manufacturers.  I fully respect that the business of business is business, and have no problem with food companies working to sell their food!  But it is for that very reason that they should NOT be the ones to decide how to highlight nutritional quality.  Food sellers deciding how to inform consumers about nutritional quality is a classic case of the fox guarding the hen house.

The IOM recommendations tell manufacturers what is expected- and while compliance with the expectations is voluntary, the heavy hand of regulation looms if compliance is poor.

But the group seemed to ignore the fact that the information they are proposing to put on the front of the pack is already on the back-of-pack in every case.  Do we truly think that the fundamental limitation to consumers’ ability to judge relative nutritional quality is their inability to turn the box around?

The group also seemed to ignore that a long history of efforts based on highlighting just negative nutrients have resulted in very poor food choices indeed.  Warned against an excess of dietary fat, the public followed front-of-pack messages about ‘low fat’ to such questionable choices as SnackWell cookies.  While accounting for several nutrients at a time may make similar missteps a bit less likely, there is much missed by simply noting what ‘bad’ stuff is or isn’t in a food.

The US food supply offers a staggering variety of products, in the neighborhood of 800,000!  These products range from marshmallows, jellybeans, and fried pork rinds- to spinach and kale.  In between is everything from orange juice, kiwis, cauliflower, potatoes, salmon, chicken, beef, pizza, milk, and margarine- to milk chocolate, dark chocolate, avocado, walnuts, olives, and blue cheese salad dressing.

A 0 to 3 scale, one nutrient at a time, or several bundled together, risks truly massive compression of such diversity.  If thresholds for points on such a scale are placed reasonably high, to safeguard health, an enormous percentage of processed foods will all get the same low score.  Conversely, if the threshold for scaling is placed low enough so that a reasonable percentage of processed foods can ‘register’ on the same scale as broccoli or spinach, then the ability to make distinctions at the high end of the scale is lost.  Efforts to date to express nutritional quality on a scale with just several values result in over 70% of all items in the supermarket getting the same score- meaning, 7 times out of 10, such a system fails to help you make a choice.

A system that highlights  five faults can reach only one possible conclusion about diet soda, which- while in my opinion a chemistry experiment gone bad- is free of all five: it is the perfect food!  Orange juice would not fare nearly so well.  Neither would lightly salted nuts; or canned tuna; or canned vegetables with added salt; or canned peaches.  The IOM system will make no distinction between bread made from refined grain, and bread made from whole grain, provided they are matched for the five faults.  Potatoes and broccoli will look identical.  A packet of raw walnuts – increasingly recognized for their outstanding nutritional profile – will wind up looking bad, due to calories and fat.  Pretzels and some chips might well look better- while offering almost no nutritional value.

Artificially sweetened fat-free yogurt will look every bit as good as plain, despite the addition of chemicals.   Salmon and steak might well look comparable, despite the recognized health benefits of the omega-3 in the fish- because the IOM system ignores omega-3.

Such a system might help belie the selective representations of food-sellers.  But it surely will not lead reliably and consistently to easy identification of the more nutritious choice on the shelf in front of you.  And since shopping is all about making choices- quick, convenient, informed choices- a system that doesn’t get you there falls short of the mark.

In fact, there really is just one word for nutrition guidance that does not lead reliably to better nutrition among the real-world choices real-world shoppers routinely confront: misguided.




Dr. David L. Katz;