Every five years, the Departments of Agriculture (USDA) and Health and Human Services (HHS) update their Dietary Guidelines for Americans — their detailed directions for what we should and shouldn’t eat to stay as healthy as possible.

Earlier this month, a committee established by those two government agencies issued its preliminary 2010 guidelines. The recommendations follow the general outline of past ones: Eat more fruits and vegetables and whole grains and less sugar, fat and salt. But the new guidelines take specific recommendations a bit further. For example, the committee recommends we limit calories from saturated fat to 7 percent of our daily calories rather than to 10 percent, as recommended in the 2005 guidelines. And it suggests we take in no more than 1,500 mg of sodium daily rather than the 2,300 mg limit set in the previous guidelines.

But, as Consumer Reports has noted, “what sets this year’s guidelines apart from previous years is how it plans to achieve them. The committee acknowledges the ‘daunting public health challenge’ of promoting healthy eating in the face of ‘powerful influences that currently promote unhealthy consumer choices, behaviors, and lifestyles.’ The committee seems to say that people can’t change the way they eat on their own — they need to have access to healthier choices.”

What the experts say
Are these dietary guidelines an improvement over past ones? In an article appearing in today’s L.A. Times, leading nutrition experts from around the country comment about what they like and don’t like in the updated recommendations. Overall, they seem impressed, particularly because the new guidelines emphasize plant-based foods and are more specific about de-emphasizing such dietary no-nos as added sugar (including in sugary soft drinks), solid fats, sodium (salt) and refined grains.

Read the L.A. Times article for all the experts’ comments. Here are some selections from those comments that I found particularly interesting:

From Marlene Schwartz, deputy director, Rudd Center for Food Policy and Obesity at Yale University:

• “My favorite sentence was from the conclusion of the executive summary, where they encourage all stakeholders to help ‘make every choice available to Americans a healthy choice.’ So often, people who sell unhealthy foods say that they are only ‘providing choices,’ as if promoting foods high in sugar, salt and fat is some type of patriotic gesture. Choice does not have to be choosing between apple slices and French fries; it could be choosing among apples, oranges and pears. I would be thrilled if we could get to the point where people realize that an array of healthy, delicious foods still provides choices.”

From Dr. Walter C. Willett, chairman of the nutrition department at the Harvard School of Public Health:

• "[T]he recommendation for three servings of milk per day is not justified and is likely to cause harm to some people. The primary justification is bone health and reduction of fractures. However, prospective studies and randomized trials have consistently shown no relation between milk intake and risk of fractures. On the other hand, many studies have shown a relation between high milk intake and risk of fatal or metastatic prostate cancer, and this can be explained by the fact that milk intake increases blood levels of IGF-1, a growth-promoting hormone. The justification for drinking three glasses of milk per day on the basis of increasing potassium intake is also not valid as the extra calories, even with low-fat milk, would easily counterbalance the benefit of the extra potassium. Also, the recommendation for people of all ages to drink three servings of milk per day is very radical and would double dairy production if adopted; this would have huge environmental impacts that would need to be considered."

From Alice Lichtenstein, director of the Cardiovascular Nutrition Lab at Tufts University School of Medicine:

• "Regardless of diet quality, the most critical issue for Americans is body weight. Even an ideal diet in excess of caloric needs is going to result in weight gain. That is, too much of a good thing can also be bad, and that's a concept that can get lost in translation. We need to talk about what foods should displace other foods, not that you should be adding whole wheat muffins to what you're already eating in the morning."

From Dr. Dean Ornish, president of the Preventive Medicine Research Institute in Sausalito, Calif.:

• "Finally, it would have been helpful to discuss more fully that what we include in our diet is as important as what we exclude. There are literally hundreds of thousands of protective substances that are found primarily in fruits, vegetables, whole grains, legumes and soy products. Instead of thinking about diet primarily in terms of reducing risk of illness and premature death, I find it much more useful to talk about how much better you look and feel when you eat and live more healthfully. Joy of living is much more sustainable than fear of dying."

You can comment on the guidelines yourself here. You have until July 15.