GoKawiilThe Make America Healthy Again (MAHA) initiative, spearheaded by US health secretary Robert F. Kennedy Jr, aims to “confront chronic disease, improve nutrition, and lower healthcare costs”. To achieve these laudable aims, those in the MAHA movement have set out to overhaul US health policies on aspects such as nutrition and vaccines and what they see as an over-reliance on medication. Such huge shifts in the United States are likely to have ripple effects around the world.
Kennedy says the MAHA policies are based on “gold standard” science. Some aspects have garnered support from the research community. But in other areas, critics say, the MAHA platform includes claims that are misleading or hyperbolic — for example, those around the efficacy of vaccines and the risk factors for autism spectrum disorder.
What does the science say? Nature spoke to researchers about some of the MAHA initiative’s prominent talking points.
‘Eat more meat and dairy to stay healthy’
On 7 January, the US health and agriculture departments launched their Dietary Guidelines for Americans for 2025 to 2030, a set of recommendations that shape the country’s nutrition and health policies, such as establishing food choices in schools. The guidelines call for US citizens to “eat more real food”, notably diets rich in red meat, full-fat dairy products, fresh fruits and vegetables, with strict limits on added sugars and ultra-processed foods. “Most of their statements are consistent with old statements to focus on real foods,” says Christopher Gardner, director of nutrition studies at the Stanford Prevention Research Center in Palo Alto, California.
But, Gardner says, the guidelines’ emphasis on red meat and dairy results in an increase in the recommended protein intake — from 0.8 grams per kilogram of body weight per day to between 1.2 and 1.6 grams. The recommendation thus sidesteps a 2025 systematic review of protein requirements, which concluded that there wasn’t enough evidence to change the 0.8-gram suggestion1. The dietary guidelines have previously set recommendations in terms of servings of food rather than grams of nutrients. As a result, Gardner says, “the new number was out of left field”.
Gardner was one of 20 people appointed to the 2025 Dietary Guidelines Advisory Committee (DGAC), an independent group that advises the US Department of Health and Human Services (HHS) and the Department of Agriculture on the development of dietary guidelines. In December 2024, the committee prepared a 421-page report collating the latest science underlying the guidance.
The MAHA initiative’s slogan adorns the headquarters of the US Department of Health and Human Services, which is spearheading the campaign.Credit: Francis Chung/POLITICO via AP Images/ALAMY
A separate, supplemental review was subsequently produced by a nine-person committee appointed by the administration of US President Donald Trump. This was used in the creation of the 2025–30 guidelines, alongside some recommendations from the DGAC.
Walter Willett, a physician and nutrition researcher at the Harvard T.H. Chan School of Public Health in Boston, Massachusetts, says that some of the research underpinning the latest guidelines did not undergo a substantive review process that was open to public comment. “The documents attached to the guidelines have nowhere near the rigour of the published report conducted by the original expert committee,” he says.
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