BOSTON — While noting that motivation for the research was valid, the Whole Grains Council questioned the data and conclusions of a study released last week by researchers from the Harvard School of Public Health claiming that products using the Whole Grain Stamp contain more sugar and more calories than products without the stamp.

In issuing their findings, the researchers said their analysis indicates that “consumers may be misled by the promised healthfulness that the (Whole Grain Stamp) symbol implies.”

But in a lengthy rebuttal on the organization’s web site (www.wholegrainscouncil.org), the W.G.C. stressed the stamp is reliable and truthful.

“We believe so passionately in the reliability and value of the Whole Grain Stamp that we feel compelled to point out several issues with this study,” the W.G.C. said. “The Whole Grain Stamp reliably and truthfully labels products containing a significant amount of whole grain. When the Whole Grain Stamp was created in 2005, our intent was to promote truth in whole grain labeling and that is what we are still doing today. The stamp was designed to denote the whole grain content of products and nothing more, and it has always been represented as such.

“The Whole Grain Stamp has been the cornerstone of one of the most successful public health and food campaigns of our time. Consumption of whole grains rose 20% in the three years following the introduction of the stamp. This success came from the combination of a new ‘rule’ (2005 U.S. Dietary Guidelines urging Americans to ‘make at least half your grains whole’) and a new ‘tool’ (The Whole Grain Stamp). Other foods recommended in the Dietary Guidelines did not show the same success.”

The W.G.C. pointed to several inaccuracies in the study, including the fact the study’s definition of a “whole grain ingredient” was based on an outdated and inaccurate list of 29 ingredients (including bran, psyllium husk etc.) that is no longer supported by the U.S. Department of Agriculture or in line with Food and Drug Administration policy.

The study also states that it collected data on 545 grain products, but the W.G.C. pointed out that supplemental materials list only 543 products, including four of which (Cape Cod Sweet Mesquite Potato Chips, Great Value BBQ Potato Chips, Great Value Ripple Cut Potato Chips, and Great Value Sour Cream and Onion Potato Chips) that contain no grain ingredients whatsoever (beyond a trace of modified cornstarch).

Another concern was that the study was skewed toward products high in sugar and calories, especially when it came to the selection of products using the Whole Grain Stamp.

The study also was not representative of whole grain products with the stamp, the W.G.C. said.

“The 113 stamped products in the study represent only 1.7% of the products using the stamp in the United States,” the W.G.C. said. “The study covered only chips, breads, cereals, bars, crackers — foods in 10 of the 49 categories in the stamped products database. Fifty-seven per cent using the stamp fall in categories not included in the study. Rice and other ‘plain grains,’ pasta, flours, oatmeal, tortillas, and many other important categories are not included in the study.”

The researchers’ study suggested using a different criterion for labeling whole grain products — a ratio of 10:1 or better of carbohydrates to fiber. The W.G.C. called the criterion “an interesting concept,” but said that when applied “may have severe drawbacks and unintended consequences.”

According to the W.G.C., four (sorghum, wild rice, brown rice and whole cornmeal) of 14 whole grains commonly eaten would not qualify under 10:1 even in their most basic unprocessed state. Additionally, many other manufactured whole grain foods — even some that are 100% whole grain and low in sugars — would not qualify under 10:1, and many products that are 10:1 are not whole grain foods and in fact may contain no whole grain ingredients, the Council said.

“It’s possible to add isolated fibers to a product full of refined grains and sugars to reach the 10:1 ratio,” the W.G.C. said. “Our experience suggests F.D.A. would find this approach misleading and unacceptable and would not allow use of the 10:1 ratio, if used on products that would not otherwise qualify as whole grains.”

The W.G.C. said the only program that may potentially improve public health is one that is widely adopted and used. The Whole Grain Stamp is now used on more than 8,000 products in 36 countries.

The group said it has worked for the past 10 years to create a whole grain labeling program that satisfies four conditions:

•It is scientifically sound

•Resonates with consumers

•Meets regulatory requirements

• Is used on a wide variety of products by most manufacturers.

“We encourage a follow up study that more accurately reflects the actual makeup of the Whole Grain Stamp program and includes the pros and cons of all approaches to whole grain labeling — including the major drawbacks of the 10:1 ratio,” the W.G.C. said.

Oldways, the parent organization of the W.G.C., has partnered with the Harvard School of Public Health on many projects, including Oldways’ Mediterranean Diet Pyramid.