In this week's news: Restaurant items shed calories; USDA sprinkles on sobering news about salt intake from sandwiches; and a study sleuths out sugar's effects on memory and the brain.

What goes up must come down; that appears to be true even of the calorie counts at big-chain restaurants. A study of 66 restaurants, including McDonald’s and Applebee’s, conducted by the Johns Hopkins Bloomberg School of Public Health determined that new items added to menus in 2013 contained an average of 12 percent fewer calories than those added in 2012. The study’s authors say the caloric reduction — about 60 calories, on average — may actually have a "significant" impact on the U.S. obesity epidemic. That is assuming, of course, that people actually order the lower-calorie options.

Sandwiches, those lunchtime staples, are a huge part of the American diet. A new study conducted by the U.S. Department of Agriculture has found that, on any given day, about 49 percent of adults across the country consume at least one sandwich, and that sandwiches constitute a surprisingly large part of our caloric and sodium intake. In fact, researchers concluded, U.S. adults get about 20 percent of our total daily sodium from sandwiches, and those who eat sandwiches tend to take in more calories (about 300 more, on average) and salt overall. Because of this, one study co-author encourages "substituting lower-sodium for higher-sodium ingredients in sandwiches," which, she says, “could significantly impact sodium intakes."

Sugar has been fingered as a culprit in a host of health issues, ranging from obesity to cavities to heart disease. Now a new study has linked sugar to memory problems and brain inflammation — at least in juvenile rats. After adolescent rats were fed a sugary beverage by University of Southern California researchers, they had much more difficulty than control groups negotiating a maze, perhaps resulting from inflammation in the hippocampus caused by the sugar. "Consuming a diet high in added sugars not only can lead to weight gain and metabolic disturbances," one co-author said, "but can also negatively impact our neural functioning and cognitive ability."