Protein Powder Label: How to Read Serving Size

Protein powder label checks start with the serving size, because every number on the panel depends on it. Read that line first, then the servings per tub, and the rest of the panel makes sense.

This guide shows how to read it, step by step, in about two minutes. It works for a tub on a shop shelf and for a photo of a label in an online listing.

What a protein powder label tells you first

Protein powder label numbers are tied to one serving, so start there. Find the serving size in grams. Then find how many servings are in the tub. Most tubs show both near the top of the nutrition panel.

Many labels list protein for one scoop. Others list it per 100 g. Both are fine, but they are not the same number. A scoop might weigh 30 g, so the per-scoop figure is lower than the per-100 g figure for the same powder. Never compare one brand per scoop with another brand per 100 g.

The Codex Alimentarius nutrition labelling guideline sets the pattern. It says protein, carbohydrate and fat should be given in grams per 100 g or per 100 ml of food. It then allows a per-serving figure as well, as long as the label also states how many servings the package holds.

Sources: Codex Alimentarius Commission, Guidelines on Nutrition Labelling (CAC/GL 2-1985), section 3.4.3.

Compare protein per 100 g, not per scoop

Scoop sizes change from brand to brand. One tub may use a 25 g scoop and another a 40 g scoop. A bigger scoop makes the protein number look larger, even when the powder itself is weaker.

The fix is simple. Look for the per 100 g column. If it is missing, do the math yourself. Divide the grams of protein per serving by the serving size in grams, then multiply by 100. A powder with 24 g of protein in a 30 g serving has 80 g of protein per 100 g.

Next, check the price per 100 g of protein, not the price per tub. Work out the total grams of protein in the tub, then divide the tub price by that number. That is total servings multiplied by protein per serving. This one number lets you compare a small tub and a big tub fairly.

Keep in mind that a protein figure on a label is a calculated value. Codex gives the usual method: measure the total nitrogen in the food and multiply it by 6.25. That means the number reflects total nitrogen, not a separate count of each ingredient.

Sources: Codex Alimentarius Commission, Guidelines on Nutrition Labelling (CAC/GL 2-1985), sections 3.4.3 and 3.3.2.

Read the ingredient order

The Codex labelling standard says ingredients should be listed in descending order of weight, from the largest amount to the smallest. So the first item is the main ingredient. On a protein powder, you want a protein source near the top, such as whey, casein, soy or pea protein.

If sweeteners, flavours or thickeners come before the protein, the tub may hold less protein than you expect. A short list is not always better. But a long list with the protein buried in the middle deserves a second look.

Sources: Codex Alimentarius Commission, General Standard for the Labelling of Prepackaged Foods (CODEX STAN 1-1985), section 4.2.1.2.

Look at the type of protein too. A blend is not wrong. It just means the first ingredient may be only part of the protein total. A label that names each protein source is easier to judge than one that says only "protein blend".

Check added sugar and energy

Flavoured powders often carry sugar. The nutrition panel shows total sugars. Codex defines sugars as all the mono-saccharides and di-saccharides in food. That includes sugar from milk, so a milk-based powder can show some sugar even with none added.

To spot added sugar, return to the ingredient list. Words such as sugar, glucose, dextrose, maltodextrin and syrup point to added carbohydrate. If they appear high on the list, the powder is part sweetener.

Energy is the other number to read. Codex says energy should be shown in kJ and kcal. Check it per serving and per 100 g. A powder with high energy and moderate protein is closer to a sweet mix than a pure protein product.

Sources: Codex Alimentarius Commission, Guidelines on Nutrition Labelling (CAC/GL 2-1985), section 2.7 (sugars) and section 3.4.2 (energy).

A quick checklist before you buy

Use this list in the shop or when you read an online listing. It takes about two minutes.

• Find the serving size in grams and the number of servings in the tub.
• Find protein per serving, then work out protein per 100 g.
• Work out the cost of each 100 g of protein from the tub price.
• Read the first three ingredients.
• Look for sugar, syrup or maltodextrin in the list.
• Check the label shows the product name and the name and address of the maker, packer, importer or seller.

Be careful with big claims on the front of the tub. A claim should match the panel on the back. If the front says high protein, the panel should show a clear protein number per serving and per 100 g. If you cannot find the numbers, treat that as a reason to look at other tubs.

This guide is general reading. Before you add a supplement, ask a doctor or dietitian if you are pregnant or have a food allergy or a health condition.

Sources: Codex Alimentarius Commission, Guidelines on Nutrition Labelling (CAC/GL 2-1985). Codex General Standard for the Labelling of Prepackaged Foods (CODEX STAN 1-1985), sections 4.1 and 4.4. Practical steps are the editors' own arithmetic on label figures.

Sources

• Codex Alimentarius Commission, Guidelines on Nutrition Labelling, CAC/GL 2-1985: https://www.fao.org/ag/humannutrition/33309-0abf2a8b4ba8ae6d0cb5fd7e0b7e6bb5b.pdf
• Codex Alimentarius Commission, General Standard for the Labelling of Prepackaged Foods, CODEX STAN 1-1985: http://www.fao.org/input/download/standards/32/CXS_001e.pdf