In its original intention centuries ago, salt was primarily used as a preservative before refrigeration was commonplace and it has always been used as a natural flavor enhancer. In our modern times though, salt has long been implicated in regards to blood pressure and heart disease, but research is now starting to show the correlation it has to obesity. A study published in the Journal of Nutrition suggests that salt is playing an even more powerful role than we thought in making us eat more.
The researchers from Deakin University gave test subjects four different lunches. The lunches looked pretty much the same—elbow macaroni with tomato sauce—but the researchers manipulated the amount of salt and fat in each pasta dish. The dishes were either low-fat/low-salt, low-fat/high-salt, high-fat/low-salt, or high-fat/high-salt. They measured how much they ate and also rated their reaction to the food on scales including pleasantness, hunger and fullness. Adding salt to the meals increased how pleasant people thought the food was. They also wanted to eat more of the high-salt meals than the low-salt meals (not surprisingly), but that didn’t hold true for the high-fat foods over those low in fat.
The higher salt content meals also made people eat 11% more food and calories, regardless of how much fat was in the meal. More interesting though was the fact that it made fat-sensitive people overeat as well. Normally the sensitivity to fat would help them limit the amount of food eaten with a higher fat content, but the addition of more salt appeared to override this control mechanism. Thus the combination of salt and fat, such as in fried foods and potato chips, seems to be one of the worst combinations to eat if one is trying to control their weight. Fat does provide twice as many calories per gram than protein and carbs, so while it has its own downfalls from a total calorie intake perspective, the addition of salt may only be making the compulsion to overeat even worse. Best defense: stick to foods in their natural forms and flavor and when someone asks you to pass the salt, just make sure it doesn’t make a stop on your plate.
Dr. Brad Niewierowski