When a voice from one side of a debate describes a report as "courageous", it is a fairly sure bet that hefty criticism will be on the way from other quarters and so it is proving with the report of the 2015 Dietary Guidelines Advisory Committee (DGAC), published last Thursday.

For food campaigner Marion Nestle the report was "honest, straightforward and courageous". There was also praise for its key recommendations from organisations such as the Center for Science in the Public Interest (CSPI), the American Heart Association and the Physicians Committee for Responsible Medicine.

However, the Grocery Manufacturers Association (GMA) said it was "concerned" that some of the report's conclusions and recommendations were "not properly based on the best available science", notably with regard to sugars, sodium, lean/processed meats and caffeine.

A significant area of concern among industry groups was the DGAC's reference to nutrient taxes as a policy option to improve diets. The report said policy changes could include "the use of economic and taxing policies to encourage the production and consumption of healthy foods and to reduce unhealthy foods".

With recommendation reduced consumption of red and processed meat, the North American Meat Institute (NAMI) regretted the report had relegated the suggestion that lean meat could also be part of a healthy diet to a footnote.
Saturated fat remains a nutrient of concern for over-consumption in the report, particularly for over 50s, but the report represents the change in how cholesterol is viewed by dietary experts. Previously, the Dietary Guidelines for Americans, last updated in 2010, recommended cholesterol intake be limited to no more than 300 mg/day. However, the report has not brought forward this recommendation and says cholesterol is not a nutrient of concern for over-consumption. However, the CSPI said the DGAC had "erred" by not including cholesterol as a nutrient of concern.

Meanwhile, the GMA and NAMI both expressed concern that including environmental sustainability as a factor in dietary advice took the DGAC beyond its remit. The GMA is "concerned that the 2015 DGAC improperly made recommendations on sustainable food production and ingredient safety, which are outside of [the] committee's expertise".

Bob Stallman, President of the American Farm Bureau Federation, said the DGAC's "lengthy foray" into sustainability issues went "well beyond both the group's expertise and its clearly defined mission". Stallman added the committee's conclusions "would have benefited from the contributions of agronomists, animal scientists, ecologists and others with deeper expertise in agriculture and sustainability".

A comment period – including a public meeting – will now run until 8 April but the political and lobbying battle over the final make-up of the 2015 Dietary Guidelines for Americans will continue for much longer. The US Department of Agriculture (USDA) and the Department of Health and Human Services (HHS), the two government agencies charged with framing the Guidelines, are expected to publish the 2015 guidelines towards the end of the year and will be subject to intense lobbying as they make their deliberations.

Hinting at the tenor of the battle to come, Republican Senator Pat Roberts, chair of the Senate Committee on Agriculture, Nutrition and Forestry, said of the report: "This is economic, not nutrition, policy." Senator Roberts called the report "disappointing", adding that it was "clear with some of these recommendations" that "the non-political, science-based process has gone awry".

Senator Roberts will not be the last politician in the coming months to bemoan, with no trace of irony, the intrusion of political influence. "The Dietary Guidelines are an essential part of combating obesity and improving the diets of all Americans," he said, "and it is crucial the guidelines be free from political influence and be completely based in nutrition science. It appears this has not been the case, and that is troubling news." He said he hoped the USDA and HHS would "restore integrity to the process and preserve the independent, unbiased and nutrition science-based nature of previous Guidelines".

The DGAC has gone further than before and broken new ground but the notion that its findings or recommendations take it beyond its remit is highly questionable.

To begin with, the contention a committee advising on nutrition cannot propose policy options with an economic or fiscal element is specious. Social policy and economic policy are intrinsically linked. Moreover, in an era where joined-up government is so critical, and in areas like nutrition and preventive health which are so multi-faceted, policy must be broad in scope and will very likely span multiple jurisdictions and competences. The alternative – where policy is developed in silos with a narrow view and scope of action – is a recipe for emasculated and ineffective government.

Nevertheless, the issue of government "overreach" is a hugely sensitive one in the US, and will be a major topic of political debate as the 2016 Presidential Election approaches. The degree to which this could affect the final guidelines is hard to hard to tell but the issue will certainly pervade the rhetoric of the debate over the coming months.

On the more general criticism the DGAC has ranged too widely in its exploration of the subject, one might look at its motivations for doing so.

In her covering letter to the two departmental Secretaries, DGAC chair Barbara Millen says the 15-member committee recognised the importance of the Dietary Guidelines in "forming the basis of federal nutrition policy and programmes" and in "providing a critical framework for local, state and national health promotion and disease prevention strategies".

The letter states that there are now 117m people in the US "with one or more preventable (her italics) chronic diseases that relate to poor quality dietary patterns and physical inactivity", while more than two-thirds of adults and nearly one-third of children and youth are overweight or obese. "These devastating health problems have persisted for decades, strained US healthcare costs and focused the attention of our healthcare system on disease treatment rather than prevention. They call for bold action and sound, innovative solutions."

The DGAC therefore viewed it as its duty to look at its brief in a broad context. The DGAC and HHS retain the prerogative not to act on all the advice but are arguably much the better off for at least hearing it.

The report itself emphasises holistic and broad-based responses: "It will take concerted, bold actions on the part of individuals, families, communities, industry and government to achieve and maintain the healthy diet patterns and the levels of physical activity needed to promote the health of the US population. These actions will require a paradigm shift to an environment in which population health is a national priority and where individuals and organisations, private business and communities work together to achieve a population-wide 'culture of health' in which healthy lifestyle choices are easy, accessible, affordable and normative – both at home and away from home."

Given the problems faced in the US are shared to some degree by most developed countries, the findings and recommendations may help policymakers elsewhere too. Stakeholders of different hues will either support or take issue with the report's findings but it has undoubtedly moved the debate forward.