December 2016 Issue
Food for Thought: Ditch the Single Nutrient Approach
By Joanne Slavin, PhD, RD
Vol. 18, No. 12, P. 14
History shows that nutrition guidance fixating on a single nutrient or ingredient as the root cause of, or solution to, obesity or chronic disease doesn't result in positive health outcomes. On the contrary, it often has negative impacts on both consumer understanding and marketplace offerings. Take dietary fat, for example. In 1980, the Dietary Guidelines for Americans (DGA) urged Americans to reduce their consumption of fat, saturated fat, and cholesterol as a way to combat obesity. Since then, science has evolved and dietary advice has shifted to instead encourage "healthy fat" consumption and lift the ban on dietary cholesterol. But the effects of the original 1980 DGA advice persist, as "low-fat" products continue to be marketed and sought by consumers today.
The new 2015–2020 DGA recognize that the key to achieving long-term healthful dietary practices isn't in focusing on single nutrients, but looking at the diet holistically to build healthful eating patterns. As the DGA states, "an eating pattern is more than the sum of its parts; it represents the totality of what individuals habitually eat and drink, and these dietary components act synergistically in relation to health. As a result, the eating pattern may be more predictive of overall health status and disease risk than individual foods or nutrients."1 While fat was the primary subject of single nutrient dietary guidance in decades past, today we're progressing down a similar path for "added sugars." To provide the public with evidence-based guidance and strategies around healthful eating that will lead to sustainable diet and lifestyle behaviors, dietitians should be prepared to provide proper education around added sugars and emphasize a total diet, rather than targeted nutrient, approach.
This article looks back at, as well as forward to, the consequences of single-nutrient guidance and offers several recommendations for dietitians to consider incorporating into their practice.
Dietary Fat Recommendations: A Case Study
Evidence Behind Dietary Fats Advice
In the 1980s, obesity rates climbed dramatically as Americans began consuming more calories than they burned.2 To curtail this situation, the federal government urged Americans, through the 1980 DGA, to reduce consumption of fat, saturated fat, and cholesterol, based on the premise that dietary fats are higher in calories and cutting back could aid weight loss. Health professionals carried this guidance through education efforts, and lower fat products were added to the marketplace. Despite these actions, obesity rates continued to rise.
In subsequent years, evidence began to reveal differences and certain benefits in the types of dietary fats, and as a result, the dietary advice had to be changed. What began as an all-limiting "avoid fat" recommendation in 1980 has been progressively downgraded over the decades to "low fat" (1990–2000) and then to "moderate fat" with an emphasis on type of fat, rather than amount (2005–2015) [See Table on page 16]. Such shifts show that our understanding of dietary fats has become much more complex and nuanced since 1980 and what was previously determined to be good dietary advice had to be abandoned as new science emerged.
Effect of Recommendation Shifts
The original dietary fat recommendations galvanized a low-fat revolution, which spread across all parts of the food environment, including nutrition policy, the industry, and consumers. Even though evidence has since evolved and dietary guidance has adapted, translation of the new research and recommendations has been challenging and resulted in confusion.
Evolving Nutrition Policy
While many consumers aren't familiar with the DGA, the policy impacts them. For example, federal nutrition assistance programs like the National School Lunch Program are required by law to implement DGA recommendations in their standards. Although it's well-known in life cycle nutrition that children need higher-fat diets during growth and development, school lunch menus were obligated to provide less than 30% of calories from fat until as recently as 2012. Today, total fat standards continue to exist for "competitive" foods sold in schools, eliminating many foods that are commonly enjoyed by students and are generally healthful—including guacamole and hummus. In July 2016, the USDA requested public comments on whether this standard ought to be eliminated based on the latest science and DGA recommendations. This action shows that while nutrition policies are adapting to accommodate new scientific understanding, change is slow and continues to impact the public even after the dietary advice has shifted.
Unintended Marketplace Consequences
The food industry frequently responds to dietary recommendations by reformulating products, sometimes with mixed results. Producing lower-fat versions of higher-fat items (eg, cheese, cream cheese, ice cream) presents many technological challenges, and because eliminated ingredients typically need to be replaced with other ingredients to preserve taste and consumer acceptance, many reformulations aren't necessarily lower in calories. And yet, when these products carry a "low-fat" marketing claim, consumers usually assume this fits the definition of "healthy." On the reverse side, until recently, many nutritious higher-fat foods, such as avocados and nuts, couldn't market themselves as "healthy" because the FDA's definition only applied to low-fat foods. In light of evolving evidence and new dietary recommendations, in September 2016 the FDA issued temporary guidance allowing companies to market foods containing predominantly mono- and polyunsaturated fats as "healthy." However, other nutrient content claims such as "lean" and "light/lite" still contain total fat thresholds. While the FDA has stated its intentions to issue similar guidance across all nutrient content claims, in the meantime, the low-fat trend continues.
Persistent Consumer Confusion
Despite new dietary recommendations, many consumers still believe fat is bad for them. In fact, 36% of consumers believe total fat is unhealthful, while 42% try to limit or avoid fats and oils entirely.3 And with news headlines sensationalizing nutrition research suggesting that high-fat foods such as butter and bacon are healthful choices, confusion is growing and causing some health-conscious consumers to question the credibility of nutrition professionals and turn to nonexperts for advice.
Added Sugars: Learning From the Past
This year, for the first time, the 2015–2020 DGA included a recommendation to limit intake of added sugars (<10% of daily calories), not because of its connection to a health outcome, but to help consumers meet nutrient needs within calorie limits. The FDA has relied on this guidance to establish mandatory labeling of added sugars on the Nutrition Facts panel, along with a DV of less than 10% of calories. Some studies have revealed that such labeling is likely to cause consumer confusion;4 history indicates the change also may cause negative marketplace effects similar to the low-fat experience.
Research shows that sugars play an important role in food, contributing to food safety, palatability, and food quality.5 But without this context, consumers may believe that any product with added sugars is bad for their health, causing them to needlessly avoid otherwise healthful products. In fact, 66% of consumers today try to limit added sugars, while only 59% attempt to limit total calories, indicating that those who are concerned about sugar may not be making more healthful dietary choices.6 Meanwhile, manufacturers are expected to reformulate foods and beverages to reduce added sugar content, possibly replacing sugars with other ingredients such as nonnutritive sweeteners or ingredients with lesser-known health effects.
Dietitians should be prepared to properly educate consumers about added sugars, without emphasizing single nutrient restriction. Some strategies include the following:
• Know the science. Understand the latest research on added sugars and be able to communicate that while people consume more than recommended amounts. Authorities, such as the FDA, acknowledge that added sugars don't cause obesity or chronic disease.7
• Explain labeling as a tool for moderation. Demonstrate to clients how labeling of added sugars can help them moderate intake of less nutrient-dense foods and identify more nutrient-dense options. Clients should understand that simply containing added sugars doesn't mean a product is unhealthful.
• Focus on the total diet. Emphasize how the overall dietary pattern matters most. The goal of food-based advice is to help consumers choose diets that provide necessary nutrients through foods, rather than encourage the avoidance of certain nutrients or ingredients that have unclear relationships to health outcomes.
— Joanne Slavin, PhD, RD, is a professor at the University of Minnesota in the department of food science and nutrition.
FoodMinds provided writing support to Joanne Slavin in the development of this article, with financial support from the Corn Refiners Association. Any opinions, conclusions, and recommendations stated are those of the author.
1. US Department of Agriculture, US Department of Health and Human Services. Dietary Guidelines for Americans 2015–2020: 8th Edition. https://health.gov/dietaryguidelines/2015/guidelines/chapter-1/
2. US Department of Health and Human Services. Health, United States, 2006: with chartbook on trends in the health of Americans. Centers for Disease Control and Prevention website. http://www.cdc.gov/nchs/data/hus/hus06.pdf. Published 2006.
3. What's your health worth? Food & Health Survey 2015. International Food Information Council website. http://www.foodinsight.org/sites/default/files/2015%20Food%20and%20Health%20Survey%20-%20FINAL.pdf
4. Laquatra I, Sollid K, Smith Edge M, Pelzel J, Turner J. Including "added sugars" on the Nutrition Facts Panel: how consumers perceive the proposed change. J Acad Nutr Diet. 2015;115(11):1758-1763.
5. Goldfein KR, Slavin JL. Why sugar is added to food: food science 101. Compr Rev Food Sci Food Saf. 2015;14(5):644-656.
6. Center for Food Safety and Applied Nutrition, Food and Drug Administration. 2014 FDA Health and Diet Survey. http://www.fda.gov/downloads/Food/FoodScienceResearch/ConsumerBehaviorResearch/
UCM497251.pdf. Published May 6, 2016.
7. Food labeling: revision of the nutrition and supplement facts labels. Federal Register website. https://www.federalregister.gov/documents/2016/05/27/2016-11867/food-labeling-revision-of-the-nutrition-and-supplement-facts-labels. Published May 27, 2016.