Correlation is not causation. The USDA’s 2015-2020 Dietary Guidelines, for the first time in 39 years, acknowledge the difference. There are three obvious shifts that make it clear that the DGAC, and indeed the USDA, finally learned that lesson.
A 10 percent limit (of total calories) for added sugars.
Sugar is one (if not the only) cause of the diseases of metabolic syndrome, apart from its calories and its effects on weight. Adults consume 15 percent of their calories in the form of added sugar, and kids consume 18 percent of their total calories as sugar.
Now that the USDA has pulled it out as a separate entity and defined the limit. Hopefully the FDA will add it to the food label. It should also influence what is available on the SNAP program, which should improve the health of the poor.
[One concern is that the USDA pie chart lists 78% of added sugar in beverages and desserts. Other analyses account for 51% of added sugar in these sources; the rest is hidden in other foods. This matters greatly.]
A 2300 mg limit for sodium.
We were at 6900 mg/day. The UK has shown that reduction of salt consumption over time has led to reductions in hypertension and stroke. While only 15-20 percent of the population is salt-sensitive, no one needs 6900 mg.
The removal of cholesterol as a risk factor.
Blood LDL-cholesterol only correlated with heart disease (never proven causative), there are many lipoproteins (some good for you) that contain cholesterol, and reductions in dietary cholesterol never proved to be remediative of heart disease in the general population.
These are all clear improvements. There are still some problems.
- equating dairy fat with red meat saturated fat
- not acknowledging fiber as an essential component of our diet (it feeds our microbiome!)
- equating all dairy as the same (milk vs. cheese vs. sweetened yogurt)
But there is one “glaring” omission. Not once in the document does it say anything about limiting processed food. Processed food is the killer. It has too little fiber, micronutrients, and omega-3’s, and too much omega-6’s, trans-fats, nitrates, branched chain amino acids, additives, emulsifiers, and of course salt and sugar.
In fact, we wouldn’t need the Dietary Guidelines if we got rid of processed food.
Robert Lustig, M.D., M.S.L.
Dept. of Pediatrics, Division of Endocrinology, Institute for Health Policy Studies, UCSF
President, Institute for Responsible Nutrition