Skip to content

Draft: not yet reviewed by a clinician

Use this page to prepare questions for your care team. It does not replace their advice. Your own targets and doses come from your nephrologist, diabetes team and renal dietitian.

Reading food labels

In short

On a US Nutrition Facts label, potassium must be listed; phosphorus does not have to be (FDA; NKF label guide). The label's Daily Values are set for healthy adults, so the "% DV" for potassium and phosphorus is misleading for you: read the milligrams (NKF; FDA: Daily Values). Always read the ingredient list first, because additives are where the hidden phosphorus and potassium are. Then check the serving size against what you will really eat.

Your numbers

Nutrient Label Daily Value (healthy adults) What to look for
Sodium 2,300 mg 140 mg or less per serving is "low sodium"; 460 mg (20 % DV) or more is high (FDA)
Potassium 4,700 mg 150 mg or less is low, 251 mg or more is high, if you have a potassium limit (AKF)
Phosphorus 1,250 mg (often not listed) any "phos" ingredient means high; 100 mg or less is low, 200 mg or more high (AKF)
Carbohydrate 275 g Total Carbohydrate × the servings you eat; this is the number for your insulin plan

Daily Values from FDA: Daily Values. A serving is not a portion: the serving is the amount on the label; the portion is what you put on your plate, and the two often differ (NIDDK).

The five-step check

  • 1. Ingredient list: look for "PHOS". Phosphoric acid, mono-, di- or trisodium phosphate, sodium hexametaphosphate, sodium tripolyphosphate, tetrasodium pyrophosphate, sodium acid pyrophosphate, di- or tricalcium phosphate, monocalcium phosphate, potassium or dipotassium phosphate, "pyrophosphate", "polyphosphate" (NIDDK; NKF). Any of these means the food is high in phosphorus whatever the number says. See Phosphate additives.
  • 2. Ingredient list: look for potassium additives. Potassium chloride (salt substitutes and many "reduced-sodium" soups, broths, sauces and deli meats), potassium lactate, potassium citrate, phosphate or sorbate, acesulfame-K. Additive potassium is about 90 % absorbed, versus 50–60 % from whole plant foods and 70–90 % from animal foods (KDIGO 2024, Figure 33; Picard 2021; DaVita). On fresh meat and poultry, also look for "enhanced" or "contains up to X % of a solution": in one study 8 of 25 enhanced products did not list their additives (Sherman and Mehta 2009).
  • 3. Milligrams per serving you will eat. Potassium: 150 mg or less is low, 151–250 medium, 251 or more high (AKF); NKF's shopping cue is 200 mg or less (NKF label guide). Phosphorus (if listed): 100 mg or less is low, 200 or more high (AKF). Sodium: 5 % DV or less (115 mg or less) is low; 20 % DV or more (460 mg or more) is high (FDA; NIDDK). FDA words: "sodium-free" under 5 mg, "very low sodium" 35 mg or less, "low sodium" 140 mg or less, "reduced sodium" 25 % less than the original (FDA; FDA claim definitions). NKF's rule of thumb: 240 mg or less per serving, and fewer milligrams of sodium than calories (NKF label guide).
  • 4. Carbohydrate. Total Carbohydrate × the servings you actually eat. Check the serving first: a package of one to two servings, such as a 20-oz soda or a 15-oz can of soup, is now labeled as one serving, so its numbers already cover the whole bottle or can; bigger packages may show a second column for the whole package (FDA). A bowl of cereal is often 1½–2 label servings. Sugar alcohols are still carbohydrate: one common method is to subtract half of them from Total Carbohydrate (Medtronic); ask your diabetes team which method to use and watch your CGM. "Diabetic" cookies, bars and shakes often add phosphate or potassium salts (DaVita). Diet colas still contain phosphoric acid (about 27 mg per 12 oz measured, 41–68 mg for some brands); clear diet sodas are phosphate-free (measured beverage phosphorus; FDC).
  • 5. Phosphorus-to-protein ratio (only if phosphorus is listed): under 10–12 mg per gram of protein is an efficient protein (egg white under 2, chicken breast about 7); processed cheese, nuts, beans and colas are not (Noori 2010; Noori 2010).

Worked example: a can of chicken noodle soup

These are typical USDA values for canned chicken noodle soup, prepared, per 1-cup serving (FDC). A can of condensed soup is labeled as more than one serving, so a full bowl may well be 2 cups. (A ready-to-serve can of up to about 2 servings is labeled as one serving, so read the serving line first: FDA.)

Label line Per serving (1 cup) If you eat 2 cups What it tells you
Sodium 831 mg (36 % DV) about 1,660 mg high: 20 % DV or more. Two cups are most of a 2,000 mg day
Potassium 60 mg (1 % DV) about 120 mg low, unless the ingredients list potassium chloride
Total Carbohydrate 7 g about 15 g about 1 carbohydrate choice for 2 cups
Protein 3 g about 6 g not much protein for a meal
Ingredients check for "sodium phosphate" in the chicken and "potassium chloride" in "reduced-sodium" versions

The verdict: a cup now and then fits; a 2-cup bowl uses most of the day's sodium. The home-made chicken noodle soup has about 130 mg sodium in a 1½-cup bowl. Soup also counts as fluid (Fluid).

More examples

  • Plant milks: two unsweetened almond milks can differ a lot. Pick one with no "phosphate" in the ingredients and check potassium per cup (NKF: milk alternatives).
  • "Reduced sodium" broth: look for potassium chloride in the ingredients before buying.
  • Breakfast cereal: the label serving may be ¾ cup; if your bowl holds 1½ cups, double every number, carbohydrate included.

Labels outside the US

UK and EU labels list salt, not sodium, usually per 100 g and per portion. Salt = sodium × 2.5, so divide the salt figure by 2.5 to get sodium: 1 g of salt is 400 mg of sodium (EU regulation 1169/2011). Potassium and phosphorus are usually not listed, so the ingredient list (steps 1 and 2) matters even more. Additives may appear as E-numbers: phosphates are in the E338–E343 and E450–E452 range, and potassium chloride is E508 (design note 03).

In the app

If barcode scanning is turned on, a scan shows the label's numbers and flags phosphate or potassium additives it finds in the ingredient list. A missing flag does not prove a food is additive-free, so read the list yourself (design note 03). You can also enter a label's numbers yourself as a custom food (Logging food; Barcodes and label photos).

Ask your care team

  1. Which numbers on the label matter most for me right now: potassium, phosphorus, sodium?
  2. Is my favorite plant milk or creamer OK?
  3. How should I count sugar alcohols with my CGM?
  4. Can a dietitian go through the labels of the foods I buy most?

Get help now if…

Labels do not cause emergencies. If you feel a low coming on while shopping or reading labels, treat it first (Treating a low). For urgent symptoms, see Get help now.

Sources

Not yet reviewed by a clinician. Facts and sources last checked 2026-10-06.