In this week's news: Comfort foods are found to be not so soothing; diet soda gets a gut check; and addiction programs quit with the sweets.

What's your go-to food when you're feeling down? Carbs? Ice cream? You might as well reach for the carrot sticks and celery -- or not snack at all. A new study has found that scarfing down comfort foods doesn't actually boost mood more than eating healthier foods -- or no food -- does. Bad moods go away, the researchers determined, whether we eat that big pile of cookies or not. "We found no justification for people to choose comfort foods when they are distressed," the researchers concluded, adding that they hoped their findings would lead people to skip the high-cal indulgences and "focus on other, food-free methods of improving their mood."

The debate over diet soda may be moving beyond whether it helps or hinders our weight-loss efforts: A study published in the journal Nature suggests the artificial sweeteners in diet soda may change our microbiomes and, in some cases, increase our risk for metabolic diseases, including Type 2 diabetes. The researchers found that, when some people were exposed to artificial sweeteners, including saccharin, aspartame and sucralose, even for only a few days, their blood sugar levels shot up to levels considered "pre-diabetic." The experiments indicated the sweeteners changed the mix of gut bacteria and caused the subjects to become glucose intolerant. Further study is needed, experts say.

People overcoming addiction to drugs or alcohol often turn to another unhealthy vice: sugar. This "transfer addicting" can lead to serious weight gain. Now, the New York Times reports, some rehab facilities are changing their approach to nutrition and diet, bringing in "culinary nutritionists," revamping meal plans, and offering nutrition education. Addiction expert Christopher Kennedy Lawford says recovery must touch on "every aspect" of an addict's life. "What you think, how you think, how you relate to people, what you put in your body, how you exercise -- it's all related," he told the Times. "And we need to get smarter about it."