Alex W.'s Blog

Can a product with "0g sugar" contain lactose?

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I am severely lactose intolerant, so I strictly avoid lactose in my diet. Unfortunately, there is no lactose free label1.

However, lactose is a sugar. So, can you use the sugar entry on a nutrition label to determine if a product has zero lactose?

Firstly, is lactose including in the analysis of “Total Sugar” on an FDA mandated nutrition label? Yes! The Food Labeling section of the Code of Federal Regulations states that: “Total sugars shall be defined as the sum of all free mono- and disaccharides (such as glucose, fructose, lactose, and sucrose).”2

Secondly, what does it mean for a product to have 0g of sugar? The CFR clarifies that 0g of sugar does not mean 0g, it actually means <0.5g. “If the serving contains less than 0.5 gram, the content may be expressed as zero.”2 Because lactose isn’t broken out from other sugars, this places a minimum upper bounds of 500 milligrams of lactose per serving for products labeled “0g sugar”.

How much is 500 milligrams of lactose? Approximately the amount of lactose in 100 grams of feta or buffalo mozzarella3, or 1/23rd as much lactose as in 1 cup of whole milk4. Most reference servings5 are around 100 grams, so “it may have up to feta levels of lactose” is the maximum precision you’ll get for most foods labeled “0g sugar”.

  1. Lactose: Characteristics, Food and Drug-Related Applications, and Its Possible Substitutions in Meeting the Needs of People with Lactose Intolerance (2022) ↩︎

  2. 21 CFR § 101.9(c)(6)(ii) - states:

    “Total Sugars”: A statement of the number of grams of sugars in a serving, except that the label declaration of sugars content is not required for products that contain less than 1 gram of sugars in a serving if no claims are made about sweeteners, sugars, or sugar alcohol content. Except as provided for in paragraph (f) of this section, if a statement of the total sugars content is not required and, as a result, not declared, the statement “Not a significant source of total sugars” shall be placed at the bottom of the table of nutrient values in the same type size. Total sugars shall be defined as the sum of all free mono- and disaccharides (such as glucose, fructose, lactose, and sucrose). Total sugars content shall be indented and expressed to the nearest gram, except that if a serving contains less than 1 gram, the statement “Contains less than 1 gram” or “less than 1 gram” may be used as an alternative, and if the serving contains less than 0.5 gram, the content may be expressed as zero.

    This is further substantiated by the AOAC’s 2018 Standard Method Performance Requirements (SMPRs®) for Sugars in Animal Feed, Pet Food, and Human Food. It lists lactose as one of the sugars that must individually be measured to meet the minimum analysis requirements, along with fructose, galactose6, glucose, sucrose, maltose. ↩︎ ↩︎

  3. The Cheese Wanker maintains a great Database of Lactose Content In Cheese sourced from a variety of scientific papers. ↩︎

  4. Whole milk has a lactose density of ~48 g / kg—see table 1 in Detection of lactose in products with low lactose content (2018)—and 1 cup of whole milk weighs 0.24 kg. This nets to 11,520 milligrams of lactose per cup of whole milk. ↩︎

  5. See Table 2 in 21 CFR § 101.12(b). Table 1 is targeted towards infants. ↩︎

  6. Lactase cleaves lactose—a disaccharide—into two monosaccharides—glucose and galactose—which your body can readily absorb. ↩︎