“Low sodium” has two very different meanings depending on context: one refers to food labeling, where it describes products containing 140 milligrams of sodium or less per serving, and the other refers to a medical condition where sodium levels in your blood drop below normal. Most people searching this term want to understand food labels or dietary guidelines, so let’s start there.
Low Sodium on Food Labels
The FDA defines several tiers of sodium claims that manufacturers can put on packaging. Each has a specific threshold per serving:
- Sodium Free: Less than 5 mg per serving
- Very Low Sodium: 35 mg or less per serving
- Low Sodium: 140 mg or less per serving
- Reduced Sodium: At least 25% less sodium than the regular version of that product
- Light in Sodium (or Lightly Salted): At least 50% less sodium than the regular version
That last distinction is important. “Reduced sodium” and “light in sodium” are relative terms. A reduced-sodium soy sauce might still contain 500 mg per tablespoon. Always check the Nutrition Facts panel rather than relying on front-of-package claims.
How Much Sodium You Should Eat Daily
The World Health Organization recommends adults consume less than 2,000 mg of sodium per day, which is roughly equivalent to one teaspoon of table salt (about 5 grams). The global average intake is 4,310 mg per day, more than double that recommendation. Most people are consuming far more sodium than they realize.
Understanding the difference between sodium and salt helps here. Table salt is about 40% sodium by weight, so 5 grams of salt contains roughly 2,000 mg of sodium. When a nutrition label lists sodium content, that number is always lower than the equivalent amount of salt, because salt also contains chloride.
If you’re managing high blood pressure or heart disease, your target may be even lower. Many cardiologists recommend staying closer to 1,500 mg per day for people with these conditions.
Low Sodium in Blood (Hyponatremia)
A healthy blood sodium level falls between 135 and 145 millimoles per liter. When it drops below 135, the condition is called hyponatremia. This is a completely separate issue from how much sodium you eat, though the two can occasionally overlap.
Mild hyponatremia may cause nausea, headaches, and fatigue. As levels drop further, symptoms can progress to confusion, muscle cramps, seizures, and in severe cases, loss of consciousness. The condition is most common in older adults, people taking certain medications (especially diuretics and some antidepressants), and endurance athletes who drink excessive water without replacing electrolytes.
Hyponatremia isn’t typically caused by eating a low-sodium diet alone. It usually results from conditions that dilute your blood sodium, like drinking too much water, kidney problems, or hormonal imbalances that affect how your body retains water.
Where Sodium Hides in Your Diet
Only about 10% of the sodium most people consume comes from the salt shaker. The vast majority comes from processed and restaurant foods. Bread, deli meats, canned soups, frozen meals, cheese, and condiments are some of the biggest contributors, not because any single serving is extreme, but because people eat them frequently.
Sodium also shows up in ingredient lists under names you might not recognize. Monosodium glutamate (MSG), sodium nitrate, sodium nitrite, and sodium bicarbonate (baking soda) all add to your total intake. These are commonly used as preservatives, flavor enhancers, and leavening agents. Checking the milligram count on the Nutrition Facts label is more reliable than scanning the ingredient list for every sodium-containing compound.
Naturally Low-Sodium Foods
Fresh, unprocessed foods are almost universally low in sodium. Most fruits contain just 1 to 6 mg per serving: apples, bananas, strawberries, grapes, oranges, and watermelon all clock in at around 1 to 3 mg per 100 grams. Fresh vegetables are similarly low. Broccoli, cauliflower, and Brussels sprouts have about 10 mg per 100 grams. Corn has essentially zero. Even potatoes, often lumped in with “starchy” foods people avoid, contain only 2 to 6 mg per 100 grams when baked or boiled without added salt.
Dry grains and legumes are also naturally low. Rice, pasta, barley, and dried beans all start under 5 mg per 100 grams before cooking. Unsalted nuts and seeds stay under 30 mg. The sodium spikes happen during processing: canned beans, flavored rice mixes, and roasted salted nuts can contain hundreds of milligrams per serving.
The pattern is straightforward. The closer a food is to its original form, the less sodium it contains. A raw tomato has 3 mg of sodium per 100 grams. Canned tomato sauce might have 400 mg or more in the same amount. Cooking at home with fresh ingredients and adding salt yourself gives you far more control than relying on packaged versions of the same foods.
Reading Labels Effectively
The most useful number on any food label is the Percent Daily Value (%DV) for sodium. This is based on a daily limit of 2,300 mg. A product with 5% DV or less per serving is considered low in sodium. A product with 20% DV or more is high. That simple rule makes it easy to compare products without doing mental math on milligrams.
Pay attention to serving sizes. A can of soup might list 800 mg of sodium per serving, but the can contains two or two and a half servings. If you eat the whole can, you’re getting close to your entire day’s worth in one sitting. Similarly, salad dressings, sauces, and condiments often have small listed serving sizes (one or two tablespoons) that understate how much people actually use.
When comparing similar products, choosing the one with lower sodium per serving adds up significantly over weeks and months. Swapping a 600 mg frozen meal for one with 350 mg, repeated five times a week, saves you over 1,000 mg of sodium weekly without changing what you eat in any dramatic way.