If the government’s latest guidelines for how to eat healthy could be boiled down to a simple directive, it would come down to six words: Less salt, less fat, less sugar.

Didn’t we know that already? Well, yes, but we haven’t been paying attention.

The last time the guidelines were issued, in 2005, Americans were urged to eat more whole grains, which prompted significant changes in foods on supermarket shelves and the ingredients used by manufacturers.

That was a step forward, but not enough to make bad eating habits a thing of the past. About two-thirds of adults and one-third of children in this country are overweight or obese. This adds to our health care bill, promotes the early onset of illness, and contributes to the incidence of deadly disease.

New guidelines issued Monday (www.health.gov/dietaryguidelines) improve on the earlier ones. They’re clear and simple: Don’t have oversize portions. Make fruits and vegetables take up half the plate. Switch to fat-free or low-fat milk. Drink water instead of sugary drinks.

Overuse of salt is one of the most common features of the American diet, and one of the worst. The guidelines limit daily salt intake to 1,500 mg (about half a teaspoon) for those 51 and over or in an at-risk category, and one teaspoon for everyone else.

No one likes to be on a diet, but it beats being in bad shape or prone to illness. Look up the rules and give them a try. And, no, don’t take that with a pinch of salt.