Nutrition labels on the food and beverages we consume should tell us the truth. So the Food and Drug Administration’s proposal to make the first significant changes in the ubiquitous fact boxes in two decades is a welcome advance for an overweight nation.

The most important change is what the FDA calls a reality check on serving sizes. People eat larger portions of many foods than they did in the 1970s and 1980s, when the current serving sizes were determined.

If you drink a whole 20-ounce bottle of soda in one sitting rather than just eight ounces, then you’re like most Americans. The same with ice cream. Most people eat a cup or more in a sitting rather than a half-cup. Serving sizes on the new labels would reflect that new reality. So when people dutifully check the label for calories and nutrients per serving, they’ll more closely match how much they’re actually consuming.

This is no nanny-state intrusion. FDA officials said the idea behind the changes it put out last week for public comment isn’t to tell people what they should eat, but rather to expand and highlight the information most useful when making food choices.

The new labels also would put a greater emphasis on calories by presenting them in bigger, bolder type. For the first time, the amount of sugar added during production would be listed. The calories from fat would no longer be included, but the total amount of fat and the amount of deleterious saturated and trans fats would be there for consumers to see.

Consumption-related conditions such as diabetes, obesity and heart disease are high on the list of the nation’s chronic health problems. Better information about nutrients and calories by itself won’t change that unhealthy reality. But truth in labeling will help those people who want to make better choices.