Evaluating ‘Make America Healthy Again’: Will It Hold Up to Scientific Scrutiny?

The Make America Healthy Again (MAHA) initiative, spearheaded by U.S. Secretary of Health Robert F. Kennedy Jr., aims to “combat chronic disease, enhance nutrition, and lower healthcare costs.” This transformative movement seeks to revamp U.S. health policies on nutrition, vaccines, and the excessive reliance on pharmaceuticals. Such significant reforms could create positive ripple effects globally.

Kennedy asserts that the MAHA policy is grounded in “gold standard” science, attracting significant support from the research community. However, critics argue that some aspects of the MAHA platform contain misleading or exaggerated claims, particularly regarding vaccine efficacy and autism spectrum disorder risk factors.

But what does the science really indicate? Nature consulted researchers to discuss key talking points from the MAHA initiative.

“Eat More Meat and Dairy for Better Health”

On January 7th, the U.S. Departments of Health and Agriculture unveiled the Dietary Guidelines for Americans for 2025-2030, which aim to influence national nutrition and health policies, including school food options. These guidelines encourage Americans to “consume more whole foods,” particularly emphasizing red meat, full-fat dairy, and fresh vegetables, while drastically limiting added sugars and ultra-processed items. Christopher Gardner, Director of Nutrition Research at Stanford Prevention Research Center, mentions that “most statements align with previous guidelines promoting real foods.”

However, Gardner notes that the guidelines raise the recommended protein intake from 0.8 grams to between 1.2 and 1.6 grams per kilogram of body weight, deviating from a systematic review conducted in 2025 that found insufficient evidence to support this increase.¹ Traditionally, dietary guidelines have focused on food sizes, not gram measurements, leading Gardner to comment that “The new Jersey number is out in left field.”

Gardner was appointed to the 2025 Dietary Guidelines Advisory Committee (DGAC), an independent group advising the U.S. Department of Health and Human Services and the Department of Agriculture in drafting dietary guidelines. A comprehensive 421-page report was released in December 2024, compiling the latest scientific research supporting their recommendations.

A supplementary review, created by a nine-member commission appointed by President Donald Trump’s administration, alongside some DGAC recommendations, informed the development of the 2025-2030 guidelines.

Walter Willett, an esteemed physician and nutrition researcher at Harvard’s T.H. Chan School of Public Health, expressed concern that the research backing the new guidelines lacked thorough public review. “The documents associated with the guidelines fall significantly short of the rigor expected from the original expert committee’s published report,” he stated.

Despite these critiques, certain demographics, such as older adults and athletes focused on muscle gain, may gain benefits from increased protein intake. A 2018 study by Stuart Phillips, a leading health researcher from McMaster University, contended that older adults should consume at least 1.2 grams of protein per kilogram of body weight to prevent muscle loss.² However, an excessive intake of animal protein could elevate the risk of kidney stones, as indicated by a 2023 study.³ Furthermore, a 2010 systematic review highlighted that diets rich in processed meats correlate with increased risks of coronary heart disease and diabetes.⁴

“Ultra-Processed Foods and Chronic Diseases”

The 2025-2030 guidelines emphasize the avoidance of ultra-processed foods, sugary beverages, and items containing added sugars or non-nutritive sweeteners, effectively removing most sodas, juices, and energy drinks from consumption.

A 2024 review published in BMJ indicated that higher intake of ultra-processed foods is linked to increased mortality, cardiometabolic disorders, and mental health issues.⁵ Moreover, a prospective study from 2024 involving over 100,000 participants revealed that those consuming more ultra-processed foods exhibited slightly elevated mortality rates.⁶

Responding to the guidelines, the American Medical Association commended the administration’s focus on reducing ultra-processed foods, sugary drinks, and excess sodium that contribute to heart disease, diabetes, obesity, and other chronic illnesses.

However, Josima Mattei, a nutrition researcher at Harvard’s T.H. Chan School of Public Health, points out that not all ultra-processed foods affect health equally. Current studies have primarily established negative health impacts from two categories: sugary carbonated beverages and salted processed meats, such as sausages and bacon. Mattei adds that distinguishing health effects across different ultra-processed foods remains complex.

Foods classified as ultra-processed often include additives, colorants, sugars, and stabilizers. For instance, sweetened yogurt and bread containing preservatives fall under this category. “Some ultra-processed foods have significant nutritional value that can be overlooked. For example, bread with stabilizers may be high in fiber and B vitamins,” she notes.

“Not all additives are detrimental,” Willett explains. “Many are harmless, and some may even be beneficial.”

“Seed Oils and Inflammation”

Seed oils, typically extracted from plants like soybeans, canola, and sunflowers, are often labeled as vegetable oils. They are predominantly high in unsaturated fats but also rich in omega-6 fatty acids, which have complex interactions with inflammation that researchers still haven’t completely unraveled. A May 2025 White House MAHA Report warned of the rising prevalence of seed oils in U.S. diets and their potential link to inflammation. Kennedy stated that consumption of seed oils might be harmful; however, Mattei claims this assertion lacks scientific backing.

Overall, scientific literature supports the notion that consuming vegetable oils is preferable to replacing them with saturated fats.⁷ Mattei states this directly aligns with dietary guidelines. Despite seed oils being high in omega-6 fatty acids essential for the body, the intake of fatty fish, which provide omega-3 fatty acids, is low in the U.S. compared to other wealthy nations.

Criticism towards seed oils can be traced back to shifts in fatty acid consumption patterns, Willett explains. A 2016 review revealed a change in the omega-6 to omega-3 ratio in modern diets from 1:1 in prehistoric times to 20:1 presently.⁸ Nevertheless, Willett noted no corresponding increase in cardiovascular diseases or cancer occurrences. Over the past decade, various researchers and health advocates have focused on vilifying seed oils, identifying corn, canola, soybean, and sunflower oils as the “Hate 8.”

Numerous studies have examined whether these fatty acids cause inflammation or exhibit other health impacts. Willett noted, “None of these studies indicate an increase in inflammatory markers; some even suggest a reduction.”

This research consistently indicates that omega-6 fatty acids help lower blood cholesterol levels, with a higher intake of both omega acids correlating positively with a lower risk of cardiovascular disease.¹⁰ A 2024 study concluded that the current evidence on omega-6 to omega-3 ratios lacks beneficial implications.¹¹ Willett asserts that concerns regarding seed oils have been “debunked by numerous randomized trials and decades of longitudinal epidemiological studies.”

“Artificial Food Dyes and Health Risks”

During a press conference in April 2025, President Kennedy announced that the administration would phase out petroleum-derived synthetic dyes, starting with FD&C Red No. 3, also known as erythrosine. The 2025 MAHA report suggests that certain food additives may elevate the risk of Attention-Deficit Hyperactivity Disorder (ADHD) and cancer.

According to Mattei, “ADHD’s origins are not nutritional; they’re primarily genetic and developmental.”