Most of the sodium Americans consume was added before the food reached the kitchen. That distribution explains why removing the shaker from the table has a modest effect on the total.
Sodium does more than season
Salt suppresses microbial growth, so it functions as a preservative in cured meats, cheeses and shelf-stable products where spoilage would otherwise limit distribution.
It also changes texture. In bread it controls fermentation rate and gluten structure, and in processed meat it dissolves proteins so they bind water and hold together.
Because those roles are structural rather than decorative, reformulating a product with less sodium is a manufacturing problem, not simply a matter of using less.
Restaurant food is seasoned for the middle of the crowd
A kitchen serving hundreds of covers cannot season to individual preference, so recipes are standardized at a level that reads as flavorful to most diners.
Sodium also masks bitterness and rounds off flavors, which makes it a cheap way to make a dish taste finished. That incentive operates at every price point.
Chain restaurants add consistency pressure. A dish must taste the same across locations, which favors pre-portioned sauces and bases where sodium is already fixed.
The label tells you the amount, not the source
Nutrition labeling reports sodium per serving, and serving sizes are set by regulation to reflect typical consumption rather than what a person actually eats in one sitting.
Sodium appears under many ingredient names, including baking soda, monosodium glutamate and various phosphates, so scanning for the word salt understates the picture.
Restaurant meals are the harder case. Chains above a certain size post calorie information, but sodium disclosure is inconsistent and independent kitchens rarely publish anything.
Why palate adjustment matters more than substitution
Preference for salt is learned and shifts with sustained exposure, which is why food from a low-sodium kitchen tastes bland at first and normal some weeks later.
Acid, heat and aromatics can carry some of the load salt was doing, since brightness from citrus or vinegar makes an under-salted dish read as complete.
Potassium-based salt substitutes work chemically but are not appropriate for everyone, particularly people with kidney conditions or taking certain medications. That decision belongs with a clinician.
Where the leverage actually sits
Because the sodium is upstream, the largest changes come from shifting the proportion of meals prepared from unprocessed ingredients rather than from restraint at the table.
Gradual reformulation by manufacturers moves the population average without requiring anyone to change behavior, which is why public health attention concentrates there.
For an individual with high blood pressure or heart or kidney disease, targets are set clinically rather than by general guidance, because the appropriate number differs by condition.