Your body requires sodium to perform basic functions like transmitting messages among your nerves and keeping your heart beating. Sodium is the most prevalent electrolyte -- a particle that conducts electricity -- outside your cells. While you need sodium in your daily diet, most Americans take in too much sodium on a daily basis. This excess sodium intake can impact not only your blood pressure, but also your weight.
Sodium naturally attracts water in your body. When you take in excess sodium, water you take in pulls water toward your cells. This increases the amount of fluid in your body, a condition known as water retention. Because water has weight, an increase in sodium intake can mean you gain extra pounds as well. You maintain this water because your body works to have a balance of salt to water in your body. As long as you have excess salts, you will continue to carry extra fluid to keep your blood at the same dilution.
Just as your body retains water to keep sodium levels balanced, it also retains sodium if your fluid intake is excessive. The kidneys are responsible for filtering sodium from your body. When you take in excess fluid, hormones in your body will signal to retain as much sodium as possible. Like water retention, this type of sodium retention also contributes to weight gain.
While the average American gets more than 1,000 mg more than she should in her daily diet, restricting your intake to about 2,300 mg per day can help to reduce sodium and water retention. Foods high in salt include canned, frozen and processed foods. One sign that your weight gain is related to water or sodium retention is if you reduce your sodium intake and notice a weight loss of one to three pounds of water weight. If your weight gain is related to water retention, increasing your water intake can help to activate your kidneys’ response, encouraging the filtration of water from your system.
Sodium retention and weight gain can indicate the presence of an underlying condition and contribute to high blood pressure due to your increased fluid levels. An example of an underlying medical condition is kidney disease, which affects your ability to filter minerals like sodium and fluids from your body. Congestive heart failure and liver disease also can affect sodium filtration. Your physician can evaluate your overall health and recommend treatment options to reduce sodium retention and weight gain.