2025–2030 US dietary guidelines: Zooming into science, policy and ideology

The new 2025–2030 Dietary Guidelines for Americans promote a food-first approach while recognizing the role of supplements, which dsm-firmenich tells Nutrition Insight it supports. At the same time, the American Society for Nutrition (ASN) and a nutrition expert warn of ideological undertones and a lack of transparency in the guidance-making process.

Molecular biologist and nutritionist Marion Nestle informs us that the guidance on saturated fat has been the same for a long time: “No more than 10% of calories.”

“The science on that has not changed. These guidelines recommend eating more animal food sources of saturated fat. If followed, these would make it difficult to stay below 10%.”

The Nutrition, Food Studies, and Public Health emerita at New York University, US, also points out that the guidelines call for eating protein at levels already typically consumed. “However, Americans eat roughly twice the amount of protein required for basic function.”

Nestle adds that the guidelines blur the definition of processed foods. Under the Nova system, foods are classified by industrial formulation and additives, not by nutrient fortification alone. “Foods with added nutrients alone would not be considered ultra-processed.”

“The guidelines use the term ‘highly processed’ for foods that contain added sugars, salt, and flavor, color, and texture additives.” However, they do not clearly define what constitutes highly processed foods.

Ideological undertones to the guidelines cannot be dismissed. Nestle says the central dogma is to separate from anything to do with the former US president Joe Biden’s era — “especially equity.”

“The Biden-era guidelines committee prioritized plant-based sources of protein, while these guidelines favor animal-based sources. This is a matter of ideology, not science.”

Nutrition Insight previously explored the sexist and classist myths associated with meat-heavy diets, along with their historical roots amid the rise of carnivore diets.

Lack of transparency covers scientific evidence

Critics have argued the final guidelines diverge sharply from the 2025 advisory committee’s recommendations, raising concerns about industry influence and transparency.

Marion Nestle critiques the new US Dietary Guidelines, questioning the guidance on saturated fat and protein sources.Sarah Ohlhorst, M.S., R.D., chief science policy officer at the ASN, tells us that the 2025 Dietary Guidelines’ scientific review process lacks transparency.

“The established Dietary Guidelines Advisory Committee (DGAC) scientific review process exists to ensure that dietary guidance decisions are transparent, based on the strength of the best available science, and non-biased. It uses a clearly defined methodology, a carefully vetted panel of experts, opportunities for public input, and well-documented evidence reviews.”

“Departing from this established approach risks undermining confidence in the evidence that supports the guidelines and contributes to confusion regarding dietary guidance, ultimately undermining trust in nutrition science,” she stresses.

Furthermore, she notes that nutrition science is highly nuanced and complex. Consequently, oversimplifying dietary guidance risks can warp the evidence to promote foods or behaviors that science overall does not support.

“When guidance appears inconsistent with established evidence or introduces contradictory messaging, it can confuse consumers and reduce trust and confidence in nutrition science,” adds Ohlhorst.

Supplements retain recognition

Sonia Hartunian-Sowa, head of Translational Science and Advocacy at dsm-firmenich, North America, tells Nutrition Insight she welcomes the guidelines’ food-first approach, which is essential for long-term health and well-being. They also recognize the use of dietary supplements and fortified foods when dietary intake alone does not meet nutritional requirements. 

Sonia Hartunian-Sowa of dsm-firmenich highlights the role of supplements, including omega-3s, in filling nutrient gaps across the US population.She says the guidance supports what dsm-firmenich and the scientific community are advocating: dietary supplements can help fill nutrient gaps and improve public health outcomes across all demographics.

“Today, nutrient gaps remain a worldwide issue, affecting individuals of all income levels in countries around the world, including high-income nations like the US. In fact, many Americans fall short on the recommended intakes of key nutrients. Women are most affected, with 1 in 3 women in the US having at least one micronutrient deficiency,” Hartunian-Sowa details. 

She also points to research showing that vitamin D, found only in select foods, is at insufficient levels globally. Experts therefore advise supplementation to support health outcomes, especially for people with poor sun exposure. 

“Similarly, omega-3 intake is low across much of the population, including the US, where individuals consume far less eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) than recommended for optimal heart and brain health. The US ranks among the lowest omega-3 index levels at 2.7%.”

“These persistent nutrient gaps are influenced by dietary preferences, limited access to nutrient-dense foods, lifestyle patterns, and varying nutritional needs across different life stages. The guidelines’ acknowledgment of dietary supplements reflects this reality,” she elaborates. 

The 2020–2025 guidelines also recognized that fortified foods and dietary supplements can be helpful when it is otherwise difficult to meet nutrient needs, such as during specific life stages.

Hartunian-Sowa points to vitamin D, iodine, iron, vitamin B12, potassium, and omega-3 fatty acids as nutrients commonly underconsumed.

Sonia Hartunian-Sowa, head of Translational Science and Advocacy at dsm-firmenich.“Vitamin D, for example, is present in relatively few foods and status is largely dependent on sunlight exposure, which can vary significantly by geography, season, and lifestyle. Iron and vitamin B12 intake may be challenging for older adults and for those who consume limited amounts of animal-sourced foods, while iodine intake can vary depending on food choices and fortification practices,” she details.

Omega-3 in spotlight 

Hartunian-Sowa points out omega-3s’ proven benefits for heart, brain, eye, and immune health. DHA is especially crucial for brain development in early life and cognitive function in healthy aging. At the same time, recent research suggests DHA may help slow the aging process at the molecular level. 

“Low omega-3 intake is not limited to individuals who follow exclusively plant-based diets and is observed across the general population, including in those who consume fish infrequently.”

“As the original source of marine omega-3s, microalgae provide a direct, plant-based source of DHA and EPA that is suitable for vegetarian and vegan diets, while also appealing to consumers seeking environmentally responsible supplements,” she underscores.

Life stage nutrient requirements

Different life stages require different nutrients, making supplements essential. For example, Hartunian-Sow highlights that pregnancy requires additional iron, iodine, folate, and DHA, which may not be obtained solely through diet.

“Most pregnant women in the US have omega-3 intakes below recommended levels, creating an opportunity for sustainable, algal-based DHA supplements that can effectively bridge this nutritional gap while supporting environmental stewardship.” 

“Women who have low fish intakes benefit from high-dose DHA supplementation during pregnancy (600–1000mg) to reduce their risk of preterm birth, which is difficult to obtain from diet alone.” 

She points to dsm-firmenich’s algal-based life’sDHA and life’sOmega supplements as sustainable alternatives to marine-sourced omega-3s and health support for mothers and babies.

“Ultimately, while improved dietary patterns are essential, supplementation and fortification remain valuable tools for helping individuals meet nutritional needs across different stages of life — particularly for nutrients that are difficult to obtain reliably through food alone,” stresses Hartunian-Sowa.