Skip to main content

How Food Labels Can Help or Hurt a Kidney Diet.

Need To Follow a Kidney Diet?

Perhaps you’ve recently been diagnosed with Chronic Kidney Disease (CKD) and your dietitian has suggested that you follow a kidney diet and become aware of sodium and protein as well as watching fat, carbohydrates and calories. It’s simple to find this information. You can look at food labels or scan barcodes to find this data. However, if you have CKD Stage 3 or higher, your dietitian may have recommended that you need to follow a kidney diet that is specifically low sodium, low protein, low potassium, low phosphorus, and not have too much fluid intake. KidneyDiet® is an app to help you find exactly this information to help you follow a kidney diet.

New Food Labels Still Missing Data For CKD Patients

The USDA has recently updated the Nutrition Facts label you’ll find on the back of boxes, cans, and most packaged foods. This is the first major update requiring new information on labels in over 20 years. While labels are now required to list even more relevant nutrient information for today’s population needs, the labels still don’t address specific nutrients that are of concern to patients with Chronic Kidney Disease: phosphorus and water content. This article shows how to find the information you need.

Why Isn’t All Food Nutrient Data Provided?

Food labeling follows current needs. At one time it was important to prevent rickets. People needed to know if their food contained Vitamin C on the label. Today, there isn’t so much concern about rickets and therefore, Vitamin C may or may not be on a label. Because much attention has been paid to the low levels of Vitamin D that people have today, the rise in osteoporosis and anemia, and high blood pressure, you will now see Vitamin D, calcium, iron , and potassium on food labels. Because diabetics need to watch the sugar in their diet today, you will see carbohydrates, total sugars and fiber listed on the label. Heart disease and obesity drive the need to know fat content, the type of fat whether saturated or unsaturated, and cholesterol amount.

Labels Today Often Look Like This

FDA Label Guidelines

When food manufacturers label food, they do so in accordance with the U.S. Food and Drug Administration (FDA) guidelines. The FDA mandates that the following information be on labels today: Total Fat (saturated and trans fat), Cholesterol, Sodium, Total Carbohydrate (dietary fiber, total sugars, added sugars) Protein, Vitamin D, Calcium, Iron, and Potassium), … It DOES NOT say that water content or phosphorus content be listed in the nutritional panel. Therefore, USDA supplied data, whether online or in apps or elsewhere, may not comprehensively make all nutritional information available to consumers. Dietitians in the health industry are familiar with tools for testing and analyzing foods that will provide complete, accurate nutritional information for nutrients beyond what is on the label. But, the average consumer doesn’t even know that information on the label is missing. Important note about the serving size: the serving size on a food label shows the amount that people usually eat or drink. The serving size looks like it is a recommendation of how much to eat or drink; but it is NOT. All of the nutritional information on the label is in reference to the serving size, so this can really affect someone watching nutrient intake

This Table Simplifies Why This Is Important To Kidney Patients

Labels Include Missing on Labels
Calories Phosphorus
Sodium Water
Vitamin D, Calcium, Iron, Potassium


The KidneyDiet App As a Resource

Using the KidneyDiet app as a resource, you will find more complete information on nutrients. Here are a few examples to help you understand.

Canned Tomato Example

In this instance, 1/2 Cup is approximately equivalent to 120 grams. Different databases may use different units of measure. Sometimes this makes it difficult to make like comparisons. This is one more thing to be aware of when comparing foods and nutrients. The two examples below are essentially similar enough to make a comparison.

It is easy to understand that tomatoes do have a water content as shown in the left image above in the NCCDB (the Nutrition Coordinating Center Database is relied on heavily by the scientific community.). However, when you look at the Whole Peeled Tomatoes listing in the USDAB (USDA Barcode Database), you will see that no water content is listed. The “0” does not mean that there is no water in it; obviously, there is. It only means that data provided to the USDAB from packaged food manufacturers, is not required to list the water content.

Turkey Breast Example

Below is an example of the same type of discrepancy in data for phosphorus in turkey. It is likely that the item below on the right does indeed have phosphorus in the turkey breast as represented in the USDAB but it is not required that that information be presented on a label and, therefore, it does not show in the USDAB.

Once again, notice the amount and serving size of the two items. Different databases possibly use different units or different serving sizes for items that are similar. The end-user of the this data must make inferences to make like comparisons. The amounts above have been adjusted to make the portions similar. That is, 1 – 3oz. serving is similar to 1 1/2 – 2oz. servings = both are 3oz portions.

Understanding Food & Nutrition Apps and Data

Many apps today provide for the use of barcode scanning labels by pointing the device, whether it’s a phone or a pad, at the barcode and then the screen instantly shows nutritional information for that food. However, that data is also only as good as the label on the back of the box. So, you’ll still see that pertinent data is missing. This is because the branded food manufacturers are required to register foods for labeling with the USDA and that information goes into a USDA Branded Foods database (Label data from national and international Branded Foods generated by industry through a public-private partnership) which is then used by these apps to provide the data to the screens you see on your phone when you scan a barcode.

KidneyDiet. Helping You Watch The 3Ps. Phosphorus. Potassium. Protein.

KidneyDiet is an app that goes beyond the USDA Branded Foods database. When you search for a food in KidneyDiet, you will find more complete, accurate data that includes nutritional information for phosphorus and water as well as provide the glycemic index that matters to so many people who suffer from both kidney disease and diabetes. If you can, don’t scan [the barcode]. Typing in the search field will show foods with more complete nutrient profiles than processed, packaged foods that have a barcode. You’ll fare better with more complete, accurate data.

Do We Need Phosphorus?

Yes. Phosphorus is a mineral that helps to keep our bones healthy, and our blood vessels and muscles working. But, too much phosphorus is not such a good thing when you have diminished kidney function. When you have kidney disease, phosphorus can build up in your blood, which can make your bones thin and weak, and it can cause itchy skin, and bone and joint pain.

Naturally Occurring Phosphorus Versus Phosphorus As An Additive

As you may know, phosphorus naturally occurs in some foods and is often added to other foods to preserve freshness. The Turkey Breast Example listed above on the right likely has phosphorus as:

  • It naturally occurs in meat and
  • It could be added to packaged meats to preserve freshness and enhance shelf life.

So what is important to pay attention to if you use a barcode scanner to determine food nutrients, you will always get the data that is on the label on the back of the package and that information for phosphorus and water is likely not accurately reflected in your app or online database because that data is not required to be provided. So, if you see a “0”, make sure to educate yourself about the food. A “0” shown when looking at USDAB items, only means “data not available.” If you type the data into the search field in the KidneyDiet app, you will likely bypass the information you’d get by scanning a barcode. While this may be a bit less convenient, the data will be more accurate. If you can, don’t scan.

High Phosphorus Foods

Know which foods are high in phosphorus. Phosphorus is in foods rich in protein, such as meat, poultry, fish, nuts, beans, and dairy products. Eating smaller amounts of proteins (about 3 oz) will provide essential amino acids. But, don’t eat large portions that may be too high in phosphorus for a CKD patient. Same goes for eating small portions of all high phosphorus foods.

Packaged, Branded, Processed Foods are High in Phosphorus

It’s packaged, branded, processed foods that are almost always high in phosphorus, phosphate additives, and the labels don’t list it as a nutrient in the food. You have to learn to look for it in the ingredients. It hides in terms like phosphate, or PHOS-anything, pyrophosphate, etc….Some foods may have added phosphorus as a preservative, including: uncooked meats and poultry, baking mixes, frozen baked goods, cereals, bars, dressings, sauces, any thing packaged.

Low Phosphorus Foods

Which foods can you eat to be on a low phosphorus diet? Fresh fruits and vegetables (that aren’t too high in potassium), rice milk (not enriched), breads, pasta, rice, corn and rice cereals, clear sodas (not dark colas), home-brewed iced tea.

Barcode scanning = often is the USDAB result set =

“0” for phosphorus or water often means “data not available.” 

It doesn’t always mean zero.