The Surprising Link Between Salt and Weight Gain

Moderating our sodium intake may help us maintain healthier gut flora, which is associated with healthier body weight. Who saw that coming?

Monica Reinagel, MS, LD/N, CNS
3-minute read
Episode #482

People who eat more salt tend to weigh more. But maybe not for the reasons you think.

Eating a lot of salt can cause your body to retain more water, which can show up on the scale as extra pounds. But we’re not just talking about water weight here. High salt diets appear to be linked to higher body fatin particular, the kind of fat that accumulates around your middle.

There are a few obvious explanations for this. First, just think about what kinds of foods tend to be higher in salt: snacks, chips, fast food, fried foods, processed foods, and restaurant meals. It might also surprise you to know that bread is one of the primary sources of sodium in the Western diet.

All of these high-sodium foods are also relatively high in calories. Not only that, they are notoriously easy to overeat. So, if your diet contains a lot of snacks, chips, bread, fried foods, and restaurant meals, you’re not only going to be consuming a lot of salt, but probably also a lot more calories. That could certainly explain the link between sodium and weight.

There are some other possible explanations. Taking in more sodium can also increase your appetite, leading you to eat more. Salty foods can also make you thirsty, which could increase your intake of caloric beverages like soda or beer. (That’s certainly what they’re hoping when they put those bowls of salty snacks out in bars!)

If high-sodium diets are more likely to be high-calorie diets, then it’s not exactly a mystery why people who eat more salt also weigh more. But then a 2015 study found that higher sodium intake was linked to higher body weight and larger waist circumference—even when calorie intake was not higher.

That’s a little harder to explain. But some new research suggests that the link between sodium and obesity could also involve the microbiome. (Lately, it seems as if all roads lead to the microbiome, doesn’t it?)


About the Author

Monica Reinagel, MS, LD/N, CNS

Monica Reinagel is a board-certified licensed nutritionist, author, and the creator of one of iTunes' most highly ranked health and fitness podcasts. Her advice is regularly featured on the TODAY show, Dr. Oz, NPR, and in the nation's leading newspapers, magazines, and websites. Do you have a nutrition question? Call the Nutrition Diva listener line at 443-961-6206. Your question could be featured on the show.