Daniel Lubetzky

I was gratified to get an early tip about this proposal and an invitation to write a column like this from staff at the Center, now directed by Dr. Susan Mayne. Dr. Mayne and I were colleagues at the Yale School of Public Health for many years, and before that, she was one of my professors. A course she taught, “Nutrition and Chronic Disease,” made an important, early contribution to the development of my career. So thanks, Dr. Mayne – and now back to our regularly scheduled program.

The action by the FDA is, as noted, only a proposal at this point, and will be open for public commentary for some time before a final rule is established. I am taking advantage of this opportunity to make a public comment: I am strongly supportive.

To some extent, the proposal is predicated on the FDA’s ongoing consumer research, which informs decisions about what information on food labels people understand and find useful. But in this case in particular, the proposal is tethered explicitly to the report of the 2015 Dietary Guidelines Advisory Committee. That committee’s report is also just a “proposal,” and one now subject to the rough and tumble of political horse-trading. Many of us in public health science feel that politicians have no business reinventing the evidence-based nutrition guidance of content experts to satisfy the demands of their most vociferous lobbyists, and should leave this stellar report intact as it is converted into the 2015 Dietary Guidelines for Americans. If precedent is a reliable indicator, the guidelines we get will be a blend of science and politics, and the less wholesome for it.

For now, though, we all have the report itself for interim guidance, and it is excellent. On the topic of added sugars, the DGAC cited the extensive evidence that an excess of sugar in the diet is decisively harmful to us, associated with obesity, insulin resistance and diabetes, among other hyperendemic scourges. Working from this strong base of evidence, the committee simply followed where logic led: There should be a clear recommendation for the total amount of added sugar that’s safe and reasonable to eat daily. Committee members established that amount at 50 grams for adults, which is approximately 200 calories or 10 percent of the prototypical 2000 calorie diet. This all translates to: not more than 10 percent of the calories in a healthful diet should come from added sugar.

The FDA’s proposal is to translate that very information onto food labels, and indicate not only the grams of added sugar in the product, but also how much of the percent daily value is provided by a given serving of a given food. So, for instance, if a product has 25 grams of added sugar per serving, it would represent 50 percent of daily value. More impressively, a 20-ounce Coca Cola, with its 65 grams of added sugar, would need to state that it – all by itself – provided 130 percent of the recommended daily value! That’s the point. Americans, and increasingly people all around the world, are getting more added sugar than they should eat in an entire day from a single soda, or serving of junk.

So, above all: Kudos and thanks to Dr. Mayne and the FDA. This proposal has the potential to provide a valuable, health-promoting reality check at point of purchase.

As for the emphasis on “added” sugars, reiterated in the FDA proposal, but provided initially by the Dietary Guidelines Advisory Committee: I agree completely it is justified. Noisy claims over recent years that sugar is intrinsically “poison” or “toxic” are misleading, and though well-intended, potentially quite harmful. They can result, and apparently have resulted, in such misguided folly as jettisoning fruit from the diet because, after all, fruit contains sugar. Fruit consumption is associated with less diabetes, not more, however. The claims ignore the fact that sugar, in the form of glucose, is an essential component of our bloodstream at all times, hardly consistent with the designation “poison.” And, they apparently ignore the role that sugar has played in the Homo sapien diet since even before we were “Homo,” let alone “sapien.” There is sugar – lactose – in the milk of mammal mothers of every variety, including our own. Some dietary sugar is native to us.

Added sugar is another matter, for a number of reasons. For one, when sugar is being added to foods, there is no particular check on quantity. If manufacturers have a “more is better” argument, the dose – as evidenced by the Coca Cola example above – can get absurd. For another, manufacturers do seemingly have just such an argument. Sugar, and sweetness in general, propagate appetite; sweeteners of various sorts thus figure prominently in food industry manipulations designed to maximize our eating, and their profits.

For yet another, the effects of any given nutrient are quite dependent on the company that nutrient keeps – among the many reasons why we should be thinking more about foods, and perhaps a bit less about nutrients. In fruit, for example, the intrinsic sugar is diluted by the relatively large volume, much of it water. Fruits are also generally very good sources of fiber. Soluble, or viscous, fiber forms a barrier layer in the gut that slows the absorption of sugar into the bloodstream. The effects of any given dose of sugar on health are ultimately about the metabolic processing of that sugar, and fiber can alter that substantially, blunting the rise in blood sugar, and potentially insulin as well.

That leads to a consideration of the glycemic effects of a food, which is where calculus becomes directly relevant. Among its other uses, tormenting high school students among them, calculus is used to calculate the area under a curve, such as the curve representing fluctuations in blood sugar, or insulin, following a meal or snack. Foods that cause that area to spike are highly glycemic, foods that don’t are low-glycemic, and there are important associations between the glycemic properties of foods and health effects. Generally, when sugar is intrinsic to a food, as in fruit and vegetables, the glycemic load tends to be attenuated by water volume and fiber. Absent such salutary company, added sugar in processed foods is apt to contribute far more directly to the metabolic mayhem we all hope to avoid.

In a foodscape where so much of what we eat is manufactured in plants on assembly lines, rather than grown by plants on sunlight and rain, there are inevitable caveats to the FDA’s welcome announcement. The government’s list of “added sugars” is extensive, but not comprehensive. Concerns have been expressed about important, potential ambiguities in the definition of “added” sugar, particularly in light of the food industry’s masterful navigation of any potential loophole. Because of my work with the NuVal system, which has long anticipated the FDA proposal by preferentially penalizing added sugar, and which has been used to score the overall nutritional quality of well over 100,000 foods, I have an unusually intimate view of food industry caginess when it comes to ingredient lists and nutrition facts.

Ingredients such as fruit concentrates, or date paste, blur the dividing line between “added” and intrinsic sugar, but may contribute to an excessive daily dose just the same. If there are sources of added sugar that are not on the official list of sources, we can expect the food industry to make preferential use of such ingredients to help sweeten their cake, sell it too, and not have to declare the added sugar in it. To some extent, the true value of the FDA proposal may depend on the agency’s capacity to keep the relevant definitions fully current as food industry elements engage in their customary efforts to weave around regulatory constraints.

This worry invites a closing bit of well-worn advice. The best foods of all cannot possibly have added sugar because they have nothing added; they are eaten as they come, direct from nature. They have an ingredient list just one word long, such as blueberry, banana or broccoli; avocado, kale, salmon or egg; chickpeas and lentils and water. If much of the diet is made up of wholesome foods direct from nature, the room for added sugar in the diet is much attenuated. This same reasoning extends to foods with more than one ingredient that come in packaging with nutrition facts panels. The shorter the ingredient list, and the more familiar the items listed there, the better, in general. Eat wholesome foods in sensible combinations, in other words, and almost always drink water when thirsty, and your total daily dose of added sugar, along with all other nutrients, should pretty much take care of itself. Artificially-sweetened junk food could be free of added sugar, and still be highly-glycemic junk.

But while there is some inevitable devilry in the details, the FDA proposal is sound, and timely, and welcome. The blunt indication that many potential daily choices for both food, and particularly drink, provide more than a full day’s supply of sugar will be hard to ignore, and should give us pause. If that pause invites reflection, and an alternative choice, the proposed rule will be working just as intended, and serving public health. I join my colleagues in celebrating that hope.