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Low sodium diet
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Low-sodium diet (The Basics)

Written by the doctors and editors at UpToDate

Last literature review version 19.3: September 2011 | This topic last updated: October 12, 2011

What is sodium? — Sodium is the main ingredient in table salt. It is also found in lots of foods, and even in water. The body needs a very small amount of sodium to work normally, but most people eat much more sodium than their body needs.
Who should cut down on sodium? — Nearly everyone eats too much sodium. The average American takes in 3,400 milligrams of sodium each day. Experts say that no one should have more than 2,300 milligrams a day, and many people should have even less.
Ask your doctor how much sodium you should have.
Why should I cut down on sodium? — Reducing the amount of sodium you eat can have lots of health benefits:

  • It can lower your blood pressure, which means it can help reduce your risk of stroke, heart attack, kidney damage, and lots of other health problems.
  • It can reduce the amount of fluid in your body, which means that your heart doesn't have to work as hard to push a lot of fluid around. That's especially important for people who have heart failure. In people with heart failure, the heart already has a hard time keeping up with the body's needs. Any extra fluid puts a strain on the heart. In fact, in people with heart failure, eating too much sodium can lead to a trip to the emergency room.
  • It can keep the kidneys from having to work too hard. This is especially important in people who have kidney disease.
  • It can reduce swelling in the ankles and belly, which can be uncomfortable and make it hard to move.
  • It can reduce the chances of forming kidney stones.
  • It can help keep your bones strong.

Which foods have the most sodium? — Processed foods have the most sodium. These foods usually come in cans, boxes, jars, and bags. They tend to have a lot of sodium even if they don't taste salty. In fact, many sweet foods have a lot of sodium in them. The only way to know for sure how much sodium you are getting is to check the label (figure 1).
Here are some examples of foods that often have too much sodium:

  • Canned soups
  • Rice and noodle mixes
  • Sauces, dressings, and condiments (such as ketchup and mustard)
  • Pre-made frozen meals (also called “TV dinners”)
  • Deli meats, hot dogs, and cheeses
  • Smoked, cured, or pickled foods
  • Restaurant meals

What should I do to reduce the amount of sodium in my diet? — Many people think that avoiding the salt shaker and not adding salt to their food means that they are eating a low-sodium diet. This is not true. Not adding salt at the table or when cooking will help a little. But almost all of the sodium you eat is already in the food you buy at the grocery store or at restaurants (figure 2).
The most important thing you can do to cut down on sodium is to eat less processed food. That means that you should avoid most foods that are sold in cans, boxes, jars and bags. You should also eat in restaurants less often.
Instead of buying pre-made, processed foods, buy fresh or fresh-frozen fruits and vegetables. (Fresh-frozen foods are foods that are frozen without anything added to them.) Buy meats, fish, chicken, and turkey that are fresh instead of canned or sold at the deli counter. (Meats sold at the deli counter are high in sodium). Then try making meals from scratch at home using these low-sodium ingredients.
If you must buy canned or packaged foods, choose ones that are labeled “sodium free” or “very low sodium” (table 1). Or choose foods that have less than 400 milligrams of sodium in each serving. The amount of sodium in each serving appears on the nutrition label that is printed on canned or packaged foods (figure 1).
Also, whatever changes you make, make them slowly. Choose 1 thing to do differently, and do that for a while. If that change sticks, add another change. For instance, if you usually eat green beans from a can, try buying fresh or fresh-frozen green beans and cooking them at home without adding salt. If that works for you, keep doing it. Then choose another thing to change. If it doesn’t work, don’t give up. See if you can cut down on sodium another way. The important thing is to take small steps and to stick with the changes that work for you.
What if I really like to eat out? — You can still eat in restaurants once in a while. But choose places that offer healthier choices. Fast-food places are almost always a bad idea. As an example, a typical meal of a hamburger and french fries from a popular fast-food chain has about 1,600 milligrams of sodium. That’s more sodium than many people should eat in a day!
When choosing what to order:

  • Ask your server if your meal can be made without salt
  • Avoid foods that come with sauces or dips
  • Choose plain grilled meats or fish and steamed vegetables
  • Ask for oil and vinegar for your salad, rather than dressing

What if food just does not taste as good without sodium? — First of all, give it time. Your taste buds can get used to having less sodium, but you have to give them a chance to adjust. Also try other flavorings, such as herbs and spices, lemon juice, and vinegar.
What about salt substitutes? — Do not use salt substitutes unless your doctor or nurse approves. Some salt substitutes can be dangerous to your health, especially if you take certain medicines.
Do medicines have sodium? — Yes, some medicines have sodium. If you are buying medicines you can get without a prescription, look to see how much sodium they have. Avoid products that have “sodium carbonate” or “sodium bicarbonate” unless your doctor prescribes them. (Sodium bicarbonate is baking soda.)

Diabetes
INTRODUCTION — Type 2 diabetes mellitus is a disorder that disrupts the way your body uses glucose (sugar).
All the cells in your body need sugar to work normally. Sugar gets into the cells with the help of a hormone called insulin. If there is not enough insulin, or if the body stops responding to insulin, sugar builds up in the blood. This is what happens to people with diabetes mellitus.
There are two different types of diabetes mellitus. In type 1 diabetes mellitus, the problem is that the pancreas (an organ in the abdomen) does not make enough insulin. In type 2 diabetes mellitus, the pancreas does not make enough insulin (figure 1), the body becomes resistant to normal or even high levels of insulin, or both. This causes high blood glucose (blood sugar) levels, which can cause problems if untreated. In the United States, Canada, and Europe, about 90 percent of all people with diabetes have type 2 diabetes.
Type 2 diabetes is a chronic medical condition that requires regular monitoring and treatment throughout your life. Treatment includes lifestyle changes, self-care measures, and sometimes medications. Fortunately, these treatments can keep blood sugar levels close to normal and minimize the risk of developing complications.
THE IMPACT OF DIABETES — Being diagnosed with type 2 diabetes can be a frightening and overwhelming experience, and you likely have questions about why it developed, what it means for your long-term health, and how it will affect your everyday life.
For most people, the first few months after being diagnosed are filled with emotional highs and lows. If you have just been diagnosed with diabetes, you and your family should use this time to learn as much as possible so that caring for your diabetes (including testing your blood sugar, going to medical appointments, and taking your medications) becomes a part of your daily routine. (See "Patient information: Self-blood glucose monitoring in diabetes mellitus".)
In addition, you should talk to your doctor or nurse about resources that are available for medical as well as psychological support. These may include group classes, meetings with a nutritionist, social worker, or nurse educator, and other educational resources such as books, web sites, or magazines. Several of these resources are listed below (see 'Where to get more information' below).
Despite the risks associated with type 2 diabetes, most people can lead active lives and continue to enjoy the foods and activities that they previously enjoyed. Diabetes does not mean an end to "special occasion" foods like birthday cake, and most people with diabetes can enjoy exercise in almost any form. (See "Patient information: Type 2 diabetes mellitus and diet" and "Patient information: Diabetes mellitus type 2: Alcohol, exercise, and medical care".)
CAUSES OF TYPE 2 DIABETES — Type 2 diabetes is thought to be caused by a combination of genetic and environmental factors. (See "Pathogenesis of type 2 diabetes mellitus" and"Prediction and prevention of type 2 diabetes mellitus".)
Genetic causes — Many people with type 2 diabetes have a family member with either type 2 diabetes or other medical problems associated with diabetes, such as high cholesterol levels, high blood pressure, or obesity.
The lifetime risk of developing type 2 diabetes is five to 10 times higher in first-degree relatives (sister, brother, son, daughter) of a person with diabetes compared to a person with no family history of diabetes.
The likelihood of developing type 2 diabetes is greater in certain ethnic groups, such as people of Hispanic, African, and Asian descent.
Environmental conditions — Environmental factors such as what you eat and how active you are, combined with genetic causes, affect the risk of developing type 2 diabetes.
Pregnancy — A small number (about 3 to 5 percent) of pregnant women develop diabetes during pregnancy, called "gestational diabetes." Gestational diabetes is similar to type 2 diabetes, but usually resolves after the woman delivers her baby. Women who have gestational diabetes are at increased risk for developing type 2 diabetes later in life. (See "Patient information: Gestational diabetes mellitus".)
TYPE 2 DIABETES DIAGNOSIS — The diagnosis of diabetes is based upon your symptoms and the results of blood tests. (See "Diagnosis of diabetes mellitus".)
Symptoms — Before being diagnosed with type 2 diabetes, most people have no symptoms at all. In those who do have symptoms, the most common include:

  • Needing to urinate frequently
  • Feeling thirsty
  • Blurred vision

Laboratory tests — Several blood tests are used to measure blood glucose levels, the primary test for diagnosing diabetes.

  • Random blood sugar test — For a random blood sugar test, you can have blood drawn at any time throughout the day, regardless of when you last ate. If your blood sugar is 200 mg/dL (11.1 mmol/L) or higher and you have symptoms of high blood sugar (see 'Symptoms' above), it is likely that you have diabetes.
  • Fasting blood sugar test — A fasting blood sugar test is a blood test done after not eating or drinking for 8 to 12 hours (usually overnight). A normal fasting blood sugar level is less than 100 mg/dL (5.55 mmol/L).
  • Hemoglobin A1C test — The "A1C" blood test measures your average blood sugar level over the past two to three months. Normal values for A1C are 4 to 6 percent. The A1C test can be done at any time of day (before or after eating).
  • Oral glucose tolerance test — Oral glucose tolerance testing (OGTT) is a test that involves drinking a special glucose solution (usually orange or cola flavored). Your blood sugar level is tested before you drink the solution, and then again one and two hours after drinking it.

Criteria for diagnosis — The following criteria are used to classify your blood sugar levels as normal, increased risk (blood sugar levels that are higher than normal and indicate a risk of future diabetes), or diabetes.
Normal — Fasting blood sugar less than 100 mg/dL (5.55 mmol/L).
Categories of increased risk

  • Impaired fasting glucose is defined as a fasting blood sugar level between 100 and 125 mg/dL (5.6 to 6.9 mmol/L).
  • Impaired glucose tolerance is defined as a blood sugar level of 140 to 199 mg/dL two hours after an oral glucose tolerance test.
  • A1C— persons with 5.7 to 6.4 percent are at highest risk, although there is a continuum of increasing risk across the entire spectrum of subdiabetic A1C levels.

At least 50 percent of people with impaired glucose tolerance eventually develop type 2 diabetes. Even if they don't develop diabetes, these people are at increased risk of heart disease. Impaired glucose tolerance is very common; about 11 percent of all people between the ages of 20 and 74 have impaired glucose tolerance.
Diabetes mellitus — A person is considered to be diabetic if he or she has one or more of the following:

  • Symptoms of diabetes (see 'Symptoms' above) and a random blood sugar of 200 mg/dL (11.1 mmol/L) or higher
  • A fasting blood sugar level of 126 mg/dL (7.0 mmol/L) or higher
  • A blood sugar of 200 mg/dL (11.1 mmol/L) or higher two hours after an oral glucose tolerance test.
  • An A1C of 6.5 percent or higher

The blood tests must be repeated on another day to confirm the diagnosis of diabetes.
Type 1 versus type 2 diabetes — Doctors can usually tell whether a person has type 1 or type 2, but there are situations when the diagnosis is difficult to determine. In such cases, doctors often run additional tests.
TYPE 2 DIABETES TREATMENT — A full discussion of the treatment for type 2 diabetes is available separately. (See "Patient information: Diabetes mellitus type 2: Treatment" and "Patient information: Diabetes mellitus type 2: Insulin treatment" and "Patient information: Hypoglycemia (low blood sugar) in diabetes mellitus".)
TYPE 2 DIABETES COMPLICATIONS — Complications of type 2 diabetes can be related to the disease itself or to the treatments used to manage diabetes. (See "Patient information: Preventing complications in diabetes mellitus".)
PREGNANCY AND DIABETES — Women with type 2 diabetes are usually able to become pregnant and have a healthy baby. A full discussion of diabetes in pregnancy is available separately. (See "Patient information: Care during pregnancy for women with type 1 or 2 diabetes mellitus".)
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem.
This article will be updated as needed every four months on our web site (www.uptodate.com/patients).
Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.