Sodium is vital for many natural processes in the body, such as managing nerve impulses and muscle contractions, but consuming too much can cause the body to retain water. It can make a person swollen and bloated.

A Study 2019 examined how increased sodium intake affected bloating in participants. Half of the participants ate a standard “Western” diet (low in fiber) and the other half ate the high fiber DASH diet. The increase in sodium led to higher levels of bloating in both groups.

This shows that high sodium diets can cause more bloating no matter what type of diet a person eats.

Learn how to reduce bloating here.

While some research links higher sodium intake to weight gain, that doesn’t mean sodium causes weight gain. There are several reasons for this link.

Water weight

First, sodium can cause the body to retain water. This water weight is temporary, and if a person consumes less sodium, their body will get rid of the excess fluid.

The body contains a lot of water, which can cause the weight to fluctuate on a daily basis. The menstrual cycle and certain medications can further affect how a person’s body retains water.

Read six tips for reducing water weight naturally.

Processed foods

Many processed foods are high in sodium, low in fiber, and high in calories. It’s okay to eat these foods in moderation, but eating them regularly can lead to weight gain.

An older 2014 Spanish study involving 418 participants explored the association between sodium and being overweight. The results showed links between high urinary sodium and high levels:

Participants with the highest sodium intake also ate more calories, ate fewer healthy foods, and ate more snacks and other foods.

Although weight gain was not a direct result of sodium intake, the study found that because many less nutritious and processed foods contain high levels of sodium, their consumption is associated with weight gain.

Find out how processed foods affect health here.

Possible cause

Other research has investigated whether sodium plays a role in weight gain regardless of the foods that contain it.

A 2015 study analyzed the sodium and calorie intake of 458 children and 785 adults. The results suggest a link between high sodium intake and increased weight, despite calorie intake. However, the researchers noted that children who consumed more sodium exercised less, which likely played a role.

The study concluded that excess sodium plays a role in weight gain, but could not accurately identify how sodium causes weight gain or obesity.

A 2018 study found that people who ate diets with the same number of calories did not change their body fat, whether they were on a diet that was low or high in sodium.

The American Heart Association (AHA) recommends eating less than 2,300 milligrams (mg) of sodium per day. This equates to about 1 teaspoon of salt. However, they add that a daily limit of 1,500 mg is ideal for most adults.

Despite this, the average sodium intake for individuals in the United States is 3,400 mg per day.

Approximately 70% of this sodium comes from packaged, processed or restaurant foods, not the salt shaker. This is why a lot of people don’t realize how much sodium they are consuming. While they might not add a lot of salt to their food, it could already contain a surprisingly high amount.

Learn more about foods high in sodium here.

Excess sodium can harm a person’s health in several ways.

Excessive sodium intake leads to high sodium levels in the blood. This draws more water into the blood vessels, raising a person’s blood pressure.

Over time, high blood pressure puts stress on the walls of the blood vessels. This leads to a buildup of plaque which can block blood flow.

High blood pressure is a important risk factor for heart attacks and strokes.

Other health effects of excessive sodium intake include:

• heart failure
• kidney disease
• kidney stones
• enlarged heart muscle
• headache
• osteoporosis

Learn more about excessive salt levels here.

Understanding the amount of sodium in foods can help people make small changes to their diet that will have a significant positive effect on their health. The CDC presents several tips for reducing sodium, including:

Shopping at the supermarket

Since packaged foods are high in sodium, even foods that don’t taste salty can have high amounts of it. It is important to be careful when shopping.

Here are some tips for shopping for groceries:

• choose “no added salt” and “low sodium” canned foods
• read food labels before you buy
• compare products and select low sodium options
• buy fresh or frozen meat instead of cold cuts

Cooking at home

While cooking at home takes time and practice, food cooked at home is almost always less sodium and less expensive. Here are some low sodium cooking tips:

• reduce salt for flavoring using spices, lemon juice, garlic, and unsalted seasonings
• add more fruits and vegetables to meals
• use “plain” ingredients when possible (for example, plain couscous instead of frozen flavored broccoli and plain instead of broccoli with added flavor)
• avoiding sauces and packaged mixes for flavoring
• make salad dressing at home

Eat out

Restaurant foods often contain more sodium than people eat when they cook at home. While eating out is an integral part of a person’s social life, following a few simple guidelines can help them control their sodium intake when choosing restaurant meals.

Meal tips include:

• ask for nutritional information before ordering
• asking the waiter or chef to put less salt in your food
• avoid using the salt shaker on the table
• share a meal with a partner or friend
• eating out as a special treat, not a regular habit

Make small changes

Changing eating habits is difficult and adjusting to new eating habits takes time. Try to make changes gradually and don’t be put off by mistakes. Anyone who finds these changes particularly difficult might benefit from contacting a doctor or dietitian.

While these tips are a starting point, they are not exhaustive and some people, including those who live in food deserts, may find them restrictive.

This basic meal plan can provide helpful advice for people limited by budget, access, and time.

Although sodium can cause water retention, research has not proven that it causes weight gain. Processed, packaged, and restaurant foods often contain foods high in sodium, and excessive consumption of these types of foods can lead to weight gain.

However, most people in the United States consume too much sodium, which can be harmful to their health.

Eating a diet high in sodium can cause bloating and increase the risk of several health problems, such as stroke, heart failure, and kidney disease.

People can reduce the sodium content of their diets by cooking at home, reading food labels, consuming less processed and packaged foods, and checking the sodium content of meals they eat in restaurants.