Comments on the 2015-2020 Dietary Guidelines for Americans
News stories on the recently-released 2015-2020 Dietary Guidelines for Americans (USDG) focused mainly on the new limits on added dietary sugar. Some news reports had headlines about dropping the prior limit on dietary cholesterol that did not really reflect the overall new USDG. For example:
- “Eggs and coffee get the all-clear in new dietary guidelines just issued by the U.S.,” proclaimed the Los Angeles Times.
- “Government revises Dietary Guidelines for Americans: Go ahead and have some eggs” suggested the Washington Post.
To its credit, the full Washington Post article did note the importance of limiting not just saturated fat but also cholesterol. But many people never heard or read more than the headlines proclaiming that the new USDG proclaim dietary cholesterol no longer needs to be limited. This will certainly confuse Americans about how to eat. Overall these mostly-misleading headlines and reports may only add to the confusion about what nutrition research tell us most Americans are supposed to eat to reduce their risk of diet-promoted diseases. It will be up to responsible health professionals and especially RDNs to help their clients better understand what foods and food components they need to limit or consume more of to improve their health.Where the 2015 USDG Fell ShortOne step in the wrong direction was the decision of the 2015 USDG to drop the prior 2010 USDG recommendation to further limit dietary sodium intake (from 2300 to 1500mg daily) for those most likely to benefit. According to the 2010 USDG, older Americans (age 51 or older) and those of any age who are African American or who already have hypertension, diabetes, and/or chronic kidney disease were informed that strong research from RCT proved this greater reduction in sodium intake from 2300 to 1500 mg/day lowers blood pressure significantly more. The failure of 2015 USDG to support the best data showing that reducing sodium from 2,300 mg down to 1,500 mg definitely helps to more effectively lower elevated blood pressure was a step in the wrong direction. However, the American Heart Association still advises all Americans to limit sodium to no more than 1500 mg per day (1). While the 2015 USDG recommends < 2300mg sodium for the general population, it does advise Americans with hypertension and prehypertension to limit sodium to 1500 mg daily.Why drop any limit on dietary cholesterol? The prior 2010 USDG said to limit consumption of dietary cholesterol to <300 mg per day. Dropping this limit is being promoted as a big win for the meat, dairy, and especially egg industries. However, it must be noted that the 2015 USDG does not claim that an unlimited consumption of eggs and other cholesterol-rich foods is now okay. This statement from the 2015 USDG makes their position crystal clear:
“Key recommendation from the 2010 Dietary Guidelines to limit dietary cholesterol to 300mg per day is not included in the 2015 edition, but this change does not suggest that dietary cholesterol is no longer important to consider when building healthy eating patterns. As recommended by the IOM [Institute of Medicine], individuals should eat as little dietary cholesterol as possible while consuming a healthy eating pattern” (2).
Even so, it appears their decision to drop any specific upper limit for dietary cholesterol is still arguably a step in the wrong direction as it garnered so many misleading headlines. Long ago RCTs have demonstrated that total-C, LDL-C, and nonHDL-C levels all increase as dietary cholesterol increases from zero to 300mg. And serum cholesterol levels continue to increase even more as dietary cholesterol increases above 300 mg/day. In general, most foods that are higher in dietary cholesterol, such as fatty meats and dairy products (except for nonfat), are also higher in saturated fat. Strong evidence, including that from randomized controlled trials, has shown that eating patterns that reduce both dietary cholesterol and saturated fat reduce levels of atherogenic cholesterol-rich, apoB-containing lipoproteins (best reflected by nonHDL-C in standard blood lipid tests) that promote atherosclerosis and increase risk of coronary artery disease.The USDG does recommend that we eat lean meats and poultry, and notes that eating less meat, including processed meat and processed poultry, has been linked to a lower risk of heart disease. But it doesn’t offer any specific limits on the amount of red and processed meats. Instead the 2015 USDG say processed meats and processed poultry are okay as long as their intake is not sufficient to cause the overall diet to exceed the limits for sodium (<2300 mg/day) and saturated fats. However, “The science on the link between cancer and diet is extensive,” says Richard Wender, MD, chief cancer control officer for the American Cancer Society. “By omitting specific diet recommendations, such as eating less red and processed meat, these guidelines miss a critical and significant opportunity to reduce suffering and death from cancer.” Not surprisingly, the National Cattlemen’s Beef Association praised the new USDG. The CSPI points out that the new guidelines do advise Americans to eat less meat suggesting to them that the US Agriculture and Health & Human Services departments at least “partially resisted the political pressure.” Dr. Katz at Yale was less forgiving, stating that the new USDG “represent a disgraceful replacement of specific guidance with the vaguest possible language.” Clearly dropping any upper limit on cholesterol, dropping the <1500 mg/day upper limit on sodium and not specifically putting limits on red and processed meats were all steps in the wrong direction for the 2105 USDG.Where the 2015 USDG Moved in Right Direction For the first time, the 2015 guidelines took on the Sugar Association and put a specific limit on the use of added sugars. They recommended added sugars make up less than 10% of Americans’ total calorie intake. They also specified that this limit excludes naturally-occurring sugars, like those found in non-fat milk or whole fruits.Arguably switching from a myopic focus on reducing just dietary fat calories to aid weight control is a step in the right direction. Instead of just limiting fat calories, the new focus is on a healthier overall dietary pattern that puts upper limits on both saturated fat and refined sugars. Those limits are 10% of total daily calories, each. We learned the hard way that a myopic focus on only % dietary fat was unproductive. So the 2015 USDG emphasize instead the need to eat more nutrient-rich foods and cut back on calorie-dense, nutrient-poor foods and especially those high in saturated fat and/or added refined sugars. This does not change the fact that nothing is more calorie-dense than pure fats & oils. However, when past guidelines ignored evidence that calorie density was far more important than the ratio of fat/protein/carbohydrate and focused mainly on modestly reducing % fat calories the result was the commercial food industry churning out numerous “fat-free” and “low-fat” cookies, cakes, chips, donuts, and other calorie-dense nutrient-poor foods. The result was more overweight and obese Americans. Hence the new emphasis to focus more on the overall diet quality rather than simply setting unproductive limits on specific dietary factors or ratios appears a big step in the right direction.The new guidelines also mention coffee for the first time and make it clear that having a moderate amount of coffee daily can be part of an overall healthy eating plan. Overall, the focus on the overall dietary pattern is a step in the right direction and one cannot argue with the 2015 USDG advice to:
- Eat variety of vegetables (dark green, red, and orange)
- Eat fruits, especially whole fruits
- Consume grains, at least half of which are whole grains
- Pick fat-free dairy products like skim milk & yogurt*
- Replace animal fats and tropical oils with plant-based or nut-based oils.
Bottom Line: “If Americans ate according to that advice, it would be a huge win for the public’s health,” says Michael Jacobson, PhD, CSPI president. “That said, the federal government’s basic nutrition advice has remained largely unchanged for the past 35 years. The problem is that the food industry has continued to pressure and tempt us to eat a diet of burgers, pizzas, burritos, cookies, doughnuts, sodas, shakes, and other foods loaded with white flour, red and processed meat, salt, saturated fat, and added sugars, and not enough vegetables, fruit, and whole grains.”*The USDG included “low-fat” dairy products but such products are still quite high in saturated fat and cholesterol and so this inclusion is questionable for those seeking to adopt a healthier overall dietary pattern.By James J. Kenney, PhD, FACNReferences:
- http://sodiumbreakup.heart.org/sodium-411/how-much-sodium-do-you-need/
- https://www.nal.usda.gov/fnic/DRI_Energy/energy_full_report.pdf]
