Calorie (or energy) density and nutrient density have always been interesting concepts and have been frequently discussed by health experts in the last few years. The focus of these discussions has been on how to get better, simpler information to people who are attempting to make good food choices. But what exactly do these terms mean, and why are they important?

According to the Pew Research Center, about a third (34 percent) of Americans are neither exercising nor dieting; 17 percent are doing both; 8 percent are dieting but not exercising; and 40 percent are exercising but not dieting.  So, who is right?

According to the British medical journal The Lancet, heartburn is pretty common. In fact, 25 percent of Americans report experiencing heartburn at least once a month, 12 percent at least once per week and 5 percent daily. So what is heartburn? And what about gastroesophageal reflux disease (GERD)? Well, here’s a guide to provide a bit more understanding of that burning sensation in your chest.