Plaintiffs in the proposed class-action lawsuit allege the bars contain significantly more calories and fat than advertised, while the company argues the testing methods used do not capture how its ingredients function in the body.
While the lawsuit hinges on calories, the real question may come down to what counts as a calorie in modern food. David Protein bars contain esterified propoxylated glycerol (EPG), an ingredient that reportedly behaves like fat in food but not in the body.
Next-gen ingredients like EPG challenge long-standing assumptions behind nutrition labeling and underscore the regulatory challenges nontraditional ingredients present. Experts suggest the case reflects a broader industry challenge: how to measure and label ingredients that do not act like traditional fats, carbohydrates or proteins, testing the limits of a system built on decades-old definitions, much like ongoing debates around the dietary supplement framework established under DSHEA.
Testing methods under scrutiny
David’s front-of-package label states that the bars contain 28 grams of protein, zero sugar and 150 calories. The plaintiffs, which hired an accredited lab to analyze the bars, allege lab tests found David products contain up to 83% more calories and up to 400% more fat than stated on their labels. The complaint says they used standard nutrient calculations (Atwater factors) and lab testing methods normally used for food labeling.
The complaint asserts that Linus Technologies violated Food and Drug Administration regulations by using misleading health statistics to drive sales, capitalizing on the growing “proteinification” trend that has driven demand for high-protein, low-calorie foods.
David Protein CEO Peter Rahal disputed the allegations, saying the lawsuit relies on inappropriate testing methods that overstate calorie content. In a statement, Rahal said the plaintiffs’ use of bomb calorimetry fails to account for how certain ingredients—including the fat substitute EPG—are metabolized in the body.
“If you burn ingredients like… EPG in a calorimeter, [they] would appear to deliver far more calories than the body actually metabolizes,” he said, adding that the company’s labeling is accurate and compliant with FDA regulations.
Who’s right? Experts say… it’s complicated
Experts say the answer depends on how calories are defined and measured.
Robert Wildman, PhD, a licensed dietitian and international authority on protein, told NutraIngredients that the dispute comes down to whether calories are measured as total energy in a lab or as “metabolizable energy”, the amount the body can actually use.
“There’s a difference between total energy measured in a lab and metabolizable energy,” he said. “Methods like bomb calorimetry capture the total heat released when a food is burned, but that doesn’t always reflect how much energy the body actually absorbs. When ingredients aren’t fully metabolized, those methods can overestimate the actual calories delivered.”
On the regulatory front, the answer falls into a regulatory gray zone. Amber Littlejohn, counsel at Holon Law Partners, said FDA rules allow for multiple accepted methods of calculating calories, meaning different approaches can yield different results without necessarily violating labeling requirements.
“There are six FDA-accepted methods to determine caloric values,” she said, noting that while standard formulas like the 4-4-9 method—which calculates calories based on grams of protein, carbohydrates and fat—are commonly used, they are not the only permissible approach.
That flexibility is relevant for newer ingredients in particular. Littlejohn told NI that the appropriate testing method can vary depending on a substance’s chemical and physiological properties and that FDA may treat ingredients differently if there is sufficient science to back it up.
“Two different legally permissible testing methods may yield different results,” she said. “The choice of one method over the other would not alone constitute misbranding.”
She added that courts generally defer to the FDA’s scientific and regulatory framework when evaluating such disputes. As a result, discrepancies between lab testing and labeled values do not automatically mean a product is misleading, particularly when both sides rely on methods that may be considered valid under existing regulations.
As functional food innovation pushes the boundaries of how nutrients are defined, the stakes extend beyond labeling debates. Dr. Wildman said even small gaps between labeled and actual calorie intake can have real consequences, with an extra 100 calories a day potentially accumulating over time and contributing to weight gain. For consumers and athletes alike, those differences highlight the importance of the way calories are measured—and how it’s communicated.
