The Dietary Guidelines Advisory Committee (DGAC) is meeting this year. The 14 members have a monumental task. They are charged with reviewing the scientific evidence since the 2010 report to make science-based recommendations to guide the 8th edition of Dietary Guidelines for Americans. Not an easy task for 14 researchers to reach consensus on such a broad topic, especially under the watchful eye of critics. For information on the process and its rationale, visit the 2015 Dietary Guidelines for Americans Questions and Answers.
 
Here are some of their challenges:
 
Lack of Consensus on Optimal Macronutrient Ratios
There isn’t a great deal of consensus right now among scientists with respect to macronutrient balance. Oh, there is little doubt that dietary fiber intakes are too low and alcohol shouldn’t be a major calorie source. However, the relative effects of dietary carbohydrates versus fats versus protein on obesity and related diseases (metabolic syndrome, nonalcoholic fatty liver, diabetes mellitus, and cardiovascular disease) are hotly debated. This can be verified by searching for diet books online. Lots of experts hawking their best recommendation. Weight loss can be accomplished with any energy-reduced diet. The only certainty is that reducing energy intake (or increasing physical activity) is required to lose extra weight. Hopefully, they will stick with the 2010 guidance “Balancing calories to manage weight”.
 
Food Groups Aren’t Relevant to Consumers
The 2015 DGAC is expected to make recommendations on foods (and beverages) and nutrients to increase and others to limit. Most likely they will continue to advocate for reduction in salt and saturated fat intake. The topic of added sugars may come up. If so, it will be a regulatory morass because measurement is impossible. Since vitamins A, D, E, C, folate, calcium, magnesium and dietary fiber are shortfall nutrients for many, there will be a continued focus on them.
 
The challenge is that food groups are becoming increasingly irrelevant. Most people do not think of preparing meals from scratch in their homes with something from each food group, with the possible exception of nutrition professionals. We are eating prepared or mostly-prepared meals.
 
Whether it is work—DC meetings for DGAC members—or pleasure, we often aren’t eating at home. We are dependent upon the nutritional quality of the foods served or available to us. Away from home food expenditures as a share of household expenditures have risen steadily since 1970, reaching  43% of household food expenditures in 2012. For the past 4 years, USDA data shows a greater increase in away from home retail than at home expenditures. And it isn’t just that we spend more money eating out, we also consume more calories, total fat, saturated fat, sodium, cholesterol and less fiber. Most importantly, one’s ability to modify food groups in a prepared meal is limited.
 
Food Groups Are Outdated
Classic food groups aren’t particularly relevant with respect to nutrients. The marketplace has iron-fortified infant cereals, vitamin D fortified dairy products, vitamin A fortified margarines, folate-fortified cereals and iodized salt. Low-salt, low-fat, low-sugar variants exist within most food categories. Even raw protein foods (e.g., chicken breasts and salmon), may have added salt. Like seafood, eggs and dairy products can be good sources of long-chain polyunsaturated fatty acids, docosahexaenoic acid (DHA). Crops (e.g., rice, potatoes and legumes), can be biofortified to be good sources of vitamin A and iron. In summary, the DGAC must acknowledge that the agriculture and food industry has transformed our food supply so that traditional food group stereotypes carry little nutritional relevance.
 
Unexpected Outcomes
A panel of nutritionists, the nutrition elite, can be expected to endorse the wholesomeness of fruit, vegetables and whole grains. Opinions may diverge with respect to the role of animal- vs. plant-based foods but traditional values will prevail. So the battle cry will probably be for a reformulation of food and beverages to make them healthier. History teaches that the food industry will follow their recommendation. After all, saturated fat was removed from many foods based on recommendations of health profession groups and previous DGAC. Unfortunately, dietary behavior is complex. The demonization of saturated fat led to a simplified solution, low-fat labeling and the adoption of an alternative, trans fats, with unexpected health consequences. If the DGAC focuses on sugar, high-fructose corn syrup and added sugars, it will drive the adoption of sugar substitutes.
 
Despite the fact that its citizens spend less on food than any other country, the world is becoming increasingly resource constrained. Policy needs science-based guidance on safe, efficient, sustainable ways to meet nutritional needs. In the end, people need calories to survive. Some amount of fat, carbohydrate and protein is essential. They also need essential vitamins and minerals. While the 2015 DGAC may aspire to recommend foods that are local and fresh, this is not a sustainable approach. As more people chose to live in urban communities, we must remember that the organic food garden at the White House wasn’t fit for consumption. This is not a unique problem. Many urban garden plots have excessive levels of heavy metals and contaminants unless new soil is brought to the garden site. We live in a world where people are dependent upon a robust agriculture and food production and distribution system.
 
The goal of the DGAC is to make science-based recommendations to steer nutrition policy, not to promote nutrition beliefs and aspirations. Hopefully, the 2015 DGAC will be preferentially guided by objective biomarkers of nutritional status rather than woefully inadequate estimates of dietary intake. Hopefully, the 2015 DGAC will be focused on achieving optimal nutrition rather than obesity and the prevention of deficiency diseases.