People who drink diet soda, but otherwise eat a healthy diet, have less risk of developing metabolic syndrome than diet-soda drinkers who eat a less healthy diet, according to a long-range, observational study. Researchers followed more than 4,000 adults for 20 years who were between the ages of 18 and 30 at the start of the study. Only 18 percent of those who mainly drank water and consumed a “prudent” diet rich in fruits, vegetables, whole grains, and fish developed metabolic syndrome. Slightly more of the participants (20 percent) who followed a similar diet, but primarily drank diet soda, developed metabolic syndrome. Participants who drank diet soda and ate a diet consisting primarily of meat, processed food, and sugar had the highest rate, with nearly a third developing metabolic syndrome. Some animal studies show that artificial sweeteners may increase appetite and food intake, but it is not clear if this is true of people as well. A healthy, balanced diet appears to be the most important factor to avoid developing metabolic syndrome if choosing to drink diet soda.