Making Sense of the New Dietary Guidelines Controversy

Message from the Author

This past week, the White House announced its rolling update of the 2025-2030 Dietary Guidelines for Americans (DGA), a set of recommendations that all federal nutrition programs are required to follow. If you find yourself here reading this, it’s likely you’ve spent much of your week inundated by everyone and their mother’s opinions about the guidelines. Hundreds of Doctorate holders, Registered Dieticians, Medical Doctors, and others with passionate interest, all opening their public communications with some variation of: “I’ve been asked to give my opinion about the new guidelines…” I’m not sure if this comes as a surprise to anyone, but, affectionately, no one has asked to hear many of these opinions; yet they’re given liberally and aggressively regardless. Nutrition, after all, much like politics, has become a religion to “worship at the altar” of. Emulsify the two, and a few things become apparent: 1) every one person knows best, 2) opinion pieces tend to take absolute stances in one direction. Rarely ever is balance provided in a matter-of-fact format that allows for deliberate and honest thought to manifest. As such, it would make sense to me that many of you are unsure what to think about the details of the guidelines. Therefore, the purpose of this article is to communicate and interpret the recent updates to the DGA in a matter-of-fact and tone-neutral presentation. Specifically, the article will 1) compare the 2020-2025 and the new 2025-2023 DGA, 2) articulate what changed scientifically and procedurally (and why that matters), 3) the rationale behind the changes, and lastly, 4) the arguments that oppose the changes. The article will rely on the language of the guidelines to avoid a misrepresentation of positions. This comparison is not about ideology or food preferences, but about how science is or isn’t translated into national policy.

I. The Role of the Dietary Guidelines for Americans

Since 1980, the Dietary Guidelines for Americans (DGA) has served as the central framework for federal nutrition policy in the United States. Produced through a collaboration between the U.S. Department of Agriculture (USDA) and the Department of Health and Human Services (HHS), this document is updated and released at least once every five years (1, 2). The 2020-2025 Dietary Guidelines’ stated objective is to offer “science-based advice on what to eat and drink to promote health, reduce risk of chronic disease, and meet nutrient needs” (2). In contrast, the 2025–2030 Dietary Guidelines report articulates its goal slightly differently, stating its purpose is to “provide clear, actionable, transparent, evidence-based guidance empowering Americans to select foods that support health and reduce chronic disease” (3).

Although the DGA is designed to improve public health, the text itself is not written directly for the average American. Instead, it targets a professional readership composed of policymakers, medical providers, and nutrition educators who are responsible for converting these technical standards into actionable advice for the public (1). Importantly, the DGA extends beyond educational messaging;all federal nutrition programs are required to follow the DGA, which means the recommendations directly affect the meals and dietary information provided to at least 1 in 4 Americans (4). Programs such as the National School Lunch Program, the Special Supplemental Nutrition Program for Women, Infants, and Children (also known as WIC), and nutrition services for the elderly all rely on the DGA to set their nutritional standards (1, 2).

The creation of the DGA is governed by the National Nutrition Monitoring and Related Research Act of 1990. This statute states that the guidelines must be based on the “preponderance of current scientific and medical knowledge” available at the time of review (2). This legal requirement is intended to ensure that federal dietary advice remains grounded in a comprehensive assessment of scientific data.

II. How the DGA is Supposed to Be Made

To understand whether the newest guidelines were created fairly, it helps to look at the official “playbook” the government is supposed to follow every five years. The USDA and HHS claim to use a specific, multi-stage process to make sure the final advice is based on solid science (we’ll address what this means and how it’s changed between guidelines) rather than just opinions (1).

The Standard 4-Stage Process

        1. Recruiting the Independent Experts

The process starts by picking a team called the Dietary Guidelines Advisory Committee (DGAC). These aren’t government employees; they’re independent doctors, nutrition researchers, and sometimes registered dieticians from across the country. Their only job is to look at the latest science and report back on what they find (1).

       2. Evidence Review and Public Meetings

The DGAC uses three main tools to figure out what Americans should be eating:

• • Deep-Dive Reviews: They look at thousands of existing studies to see what the “weight of the evidence” says.

• • Data Analysis: They look at what Americans are actually eating right now to see where we are falling short.

• • Food Modeling: They run “what-if” scenarios to see how different diets might affect our health.

To keep things honest, they hold meetings that the public can watch and allow people to send in their own comments and concerns (1).

        3. Writing the Scientific Report

After about a year of research, the committee writes a Scientific Report. Think of this as a massive, detailed recommendation letter. It isn’t the final law (yet); it’s just the experts telling the government, “Based on our investigation, here is what the science says the new rules should be” (1).

       4. Turning Science into Policy

In the final step, a team of federal staff takes that expert report and translates it into the official Dietary Guidelines for Americans. Their goal is to take “technical” science and turn it into practical advice that can be used to plan school lunches, military meals, and doctors’ recommendations (1).

When the final guidelines end up looking very different from what the experts recommended in Step 3, it often sparks a major debate about whether the government followed the science or allowed other interests to get in the way.

Why the Scientific Report Is Central

To keep the guidelines as objective as possible, the system is designed with a clear “separation of powers” – e.g., a “Church and State” arrangement between the scientists and the policy writers (2, 4).

The process is split into two distinct roles so that one doesn’t unfairly influence the other:

• • The Scientific Jury (The DGAC): They focus entirely on the research and produce the report (1,2).

• • The Policy Writers (these are Federal Staff): A separate team of government employees then takes those scientific conclusions and “translates” them into the final Dietary Guidelines policy (1).

Why They Usually Match

Historically, these two groups have been in lockstep. Because federal law requires the guidelines to reflect the, again, “preponderance of scientific evidence,” government agencies have traditionally viewed the experts’ Scientific Report as the gold standard for meeting that legal requirement 1, 4). For decades, the final policy has almost always mirrored the advice given by the independent committee. Significant deviations from this report, like those seen in the updated 2025-2030 guidelines (which we’ll get into shortly), are considered by many to be “unprecedented” (4, 5).

III. Snapshot: The 2020–2025 Dietary Guidelines

The purpose of this section is to establish the “baseline” or “control condition”, if you will, for American nutrition policy before we look at the 2025–2030 changes. This is meant to define the logic, not the correctness of the report.

The 2020–2025 DGA edition emphasized managing specific food components (e.g., saturated fat) to help people maintain a healthy weight and lower their risk of chronic disease (1,2). Keep this in mind as there is a distinction between focus on individual food components (like the 2020-2025 guidelines) and the food matrix (like the updated guidelines do). The 2020–2025 policy was built on four main pillars (1,2):

1. 1. Healthy Patterns at Every Stage: Encouraged following a healthy dietary pattern at every life stage, from infancy through older adulthood.
   2. Nutrient Density and Calories: Focused on “nutrient-dense” foods – i.e., those that provide vitamins and minerals with very little added sugar, sodium, or saturated fat.
   3. Cultural Flexibility: Designed to be adapted to fit personal preferences, cultural traditions, and different budgets.
   4. The “Limits” Rule: Set strict daily caps on four specific components with respect to total calorie intake: added sugars (<10%), saturated fat (<10%), sodium (<2,300 mg), and alcohol (2).

The 2020–2025 guidelines were built on three core scientific assumptions that had been, whether agreed totally on or not, standard in the U.S. for decades:

1. 1. Saturated Fat as a Risk Factor: Saturated fat was viewed as a primary contributor to heart disease because of its ability to raise LDL (“bad”) cholesterol (2,6).
   2. Low-Fat Dairy Preference: Because of the saturated fat limit, the guidelines recommended that everyone over age two choose fat-free or low-fat dairy products instead of whole-fat versions (2).
   3. Substitution with Vegetable Oils: The policy broadly endorsed replacing animal fats (like butter) with polyunsaturated fatty acids (PUFAs), such as those found in vegetable oils (soybean, corn, or canola), to improve heart health (2, 7)

IV. The 2025–2030 Guidelines as an Explicit Policy Reset

Historically, each new edition of the DGA built slowly upon the one before it. The 2025–2030 edition explicitly rejected this “business as usual” approach. Instead, the administration framed them as the “most significant reset of federal nutrition policy in our nation’s history” (3). The rationale was that since chronic diseases like obesity and diabetes have continued to skyrocket under the old system, a “revision” would not be enough to change the country’s health trajectory—only a complete “reset” of the foundation would work (3, 8).

Rejecting the Expert Panel’s Report

In a move that the administration described as necessary for “scientific rigor”, the 2025–2030 Guidelines explicitly rejected the 2025 Dietary Guidelines Advisory Committee Scientific Report. The administration argued that the expert panel’s report was “insufficient” and “flawed” because it focused too heavily on “health equity” rather than “what humans should eat to prevent and reverse chronic disease” (3). As a result, the government conducted its own supplemental research to create a new “Scientific Foundation” (3, 8).

Emphasis on “Real Food” and Processing

The core of this reset is a shift in focus: moving away from counting individual nutrients (like grams of fat) and toward the quality of the whole food – i.e., a focus on “food matrix.” In other words, the new guidelines prioritize foods in their most natural, minimally processed states (e.g., eggs, meat, and vegetables) over highly processed alternatives, even if those alternatives are lower in fat or calories. The running theme of the new guidelines is: “Eat Real Food” (3).

Moving Away from Fat as a Nutrient of Concern

A major part of this reset was the departure from the “uniform fat restriction” of the past. For the first time in decades, the guidelines moved away from the strict requirement that dairy must be low-fat or fat-free. By including whole-fat dairy and animal proteins as healthy staples, the 2025–2030 policy acknowledges that these foods provide essential nutrients that were often lost in the push for “low-fat” diets (3,8). Importantly, I will say this now and reinforce later. The guidelines have shifted from a monolithic stance on fat, specifically saturated fat, as a nutrient of public health concern, and have adopted a more neutral stance on this food component while remaining explicit about it being limited to >10% total calorie intake. To claim that the new administration is supporting unrestricted intake of saturated fat (a claim I have seen many people make in the past few days) is a complete misrepresentation of the new Guidelines’ language.

Justification: A Failing Food System

The administration justified this sudden change by pointing to the “failure” of the modern food system (8). With nearly 75% of Americans now overweight or obese, the 2025–2030 Scientific Foundation report argues that the previous focus on “calorie control” and “lean proteins” has clearly failed to protect the public (3, 8).

Now, lets dig into the controversy.

V. The Controversy

The 2025–2030 DGA created a firestorm in the nutrition world, not just because the advice changed, but because of how it changed. The controversy, whether you agree with the guidelines or not, is centered on a fundamental break in the standard government process (4, 5). The primary source of conflict is the massive gap between what the independent experts recommended and what the government ultimately published.

In the most recent cycle, the scientific structure changed. Although the 2025 Dietary Guidelines Committee completed its evidence reviews and submitted a Scientific Report in December 2024, the Departments of Agriculture and Health and Human Services chose not to adopt it as the primary evidentiary basis for the final Guidelines. Instead, the administration introduced a separate Scientific Foundation for the Dietary Guidelines for Americans, 2025–2030, developed through an independent evidence review process and designated as the scientific underpinning of the policy.

The administration justified this shift by arguing that the Dietary Guidelines Committee’s incorporation of a “health equity lens” imposed interpretive filters that compromised scientific objectivity. As a result, the Dietary Guidelines Committee report was reviewed selectively, with individual conclusions accepted or rejected, rather than serving as the central scientific authority.

This procedural change has been critiqued as unusual in the modern history of the Dietary Guidelines for Americans and has drawn criticism from public-health advocacy organizations, including the Center for Science in the Public Interest, which argued that the administration sidelined a two-year independent scientific review in favor of an alternative evidentiary framework (5).

Two Definitions of “Scientific Integrity”

The controversy also reveals a deep split in how people define “good science.”

• • The Advisory Committee View: Defines scientific integrity as looking at the totality of the evidence, including large observational studies that follow hundreds of thousands of people over decades (1, 4, 5).

• • The 2025–2030 DGA View: Defines integrity as prioritizing “hard” clinical trials (RCTs) that show direct cause-and-effect. They argue that if the trials don’t show that saturated fat causes death, then the observational data are just a “guess” and should be ignored (3,8).

Scientists vs. Secretaries

Finally, this situation has created a major tension between expert consensus and executive authority. In the past, the scientists were the primary authors of the “truth” behind the guidelines. In the 2025–2030 cycle, the executive branch (the Secretaries of the USDA and HHS) asserted their authority to overrule the committee, arguing that the committee had allowed “ideological bias” to cloud the science (3, 8). This, no surprise, has sparked a national debate.

At its core, the controversy reflects a broader disagreement over who should define scientific integrity in nutrition policy: an independent “expert” committee synthesizing the full body of evidence, or executive agencies exercising discretionary authority over how evidence is interpreted and applied by using panels independent from the independent panel. This tension underlies the more substantive scientific debates that we are now getting into.

VI. Scientific Evidence Underlying the Dispute

The disagreement behind the 2025–2030 Dietary Guidelines comes down to how nutrition science is interpreted. For decades, federal guidance has relied on the “diet–heart hypothesis”, which assumes that lowering saturated fat reduces cholesterol and therefore lowers the risk of cardiovascular disease (9). The current White House administration has argued that several randomized controlled trials show this chain of logic does not always hold – i.e., lower cholesterol does not consistently lead to longer life. The studies below form the core of that debate.

A. The Evidence for Changing the Guidelines

Saturated Fat: Nutrients vs. Whole Foods

Current guidelines generally recommend replacing saturated fat with unsaturated fat to lower LDL cholesterol. The new guidelines suggest that the health effects of saturated fat may depend more on the whole food it comes from (i.e., the food matrix) than on fat alone. For instance, the Milky Way Study was a double-blind randomized controlled trial published in 2021that involved 49 healthy children aged 4–6 years. It tested the recommendation that children switch to reduced-fat dairy. Over three months, children in the reduced-fat group lowered their dairy fat intake by an average of 12.9 g/day compared with those who continued eating whole-fat dairy (10). Despite this reduction in fat intake, there were no meaningful differences between the two groups. Measures of body fat, including body fat percentage and BMI, did not differ. Markers of cardiometabolic health also remained similar, including fasting LDL cholesterol, systolic blood pressure, and other risk factors. These results challenge the idea that whole-fat dairy automatically increases obesity or cardiometabolic risk.

Replacing Saturated Fat with Omega-6-Containing Vegetable Oil

Another long-standing recommendation has been to replace saturated fat with polyunsaturated fatty acids (PUFAs), especially omega-6 linoleic acid from vegetable oils (1, 2, 8). However, the current administration claim that data recovered from large historical randomized controlled trials raise questions about whether this approach improves survival.

• • Cholesterol Lowered, Survival Not Improved: The Minnesota Coronary Experiment [original study: 1968–1973 (11); reevaluated in 2016 (9)] tested replacing saturated animal fats with corn oil in 9,423 participants. The intervention lowered serum cholesterol by about 13.8% compared with baseline, but this did not lead to longer life. Among participants followed for at least one year, each 30 mg/dL (0.78 mmol/L) reduction in cholesterol was linked to a 22% higher risk of death (HR 1.22, 95% CI 1.14–1.32; P=0.001) (9).

• • The Omega-6 Issue: Data from the Sydney Diet Heart Study [original study: 1966–1973 (12); reevaluated in 2013 (13)] showed that replacing saturated fat with safflower oil (high in omega-6 linoleic acid and lacking omega-3s) increased the risk of death. All-cause mortality was higher in the intervention group (17.6% vs. 11.8%; HR 1.62, 95% CI 1.00–2.64; P=0.051), as were deaths from cardiovascular disease (HR 1.70) and coronary heart disease (HR 1.74), compared with controls consuming animal fats (13).

The researchers of the Sydney Heart Study suggest that while linoleic acid lowers cholesterol, it may also increase vulnerability to lipid oxidation (13). In the Sydney study, the intervention group saw a larger drop in total cholesterol (−13.3%) than controls (−5.5%), yet experienced higher mortality (13). This finding suggests, and the current administration in the White House agrees, that cholesterol reduction alone is not a reliable indicator of survival benefit.

B. The Evidence for Keeping the Guidelines the Same

Why Organizations and “Experts” Still Support Saturated Fat Limits

While new federal guidelines have moved toward a more “neutral” view of animal fats, many of the United States’ more prominent health organizations, including the American Heart Association and the Center for Science in the Public Interest, have pushed back. They argue that weakening the long-standing 10% limit on saturated fat overlooks what federal law calls the “preponderance of scientific evidence” that the law mandates the guidelines abide by. Although the limit of no more than 10% of saturated fat intake with respect to total caloric intake stands, the Center for Science in the Public Interest notes that the new guidelines simultaneously emphasize the consumption of animal protein, butter, and full-fat dairy. They argue that this food-based guidance “undermines” the saturated fat limit (5).

The position of the American Heart Association and the Center for Science in the Public Interest is not based on a single study. Instead, they place the greatest weight on modern, what they consider to be “well-controlled” randomized trials and large systematic reviews, and less weight on older studies they believe have serious design problems.

The Debate Over Re-Examined Older Studies

Much of the argument for relaxing saturated fat limits comes from renewed attention to two older studies: the Sydney Diet Heart Study and the Minnesota Coronary Experiment (9, 13). These trials are often cited because they found that replacing saturated fat with vegetable oils rich in linoleic acid did not reduce overall mortality. Health organizations respond that these studies should not guide current policy because of major methodological limitations.

In the Sydney Diet Heart Study, the intervention group consumed a margarine that was later found to be high in industrial trans fats (14). At the time, the dangers of trans fats were not yet understood. Today, trans fats are recognized as more harmful to heart health than saturated fats. Because of this, critics argue the study did not truly test the effects of replacing saturated fat with polyunsaturated fat alone. Instead, it unintentionally tested a substitution involving a known harmful fat, making the results difficult to interpret.

The Minnesota Coronary Experiment is criticized for different reasons. Although originally designed to run longer, changes in institutional care meant participants were followed for an average of only 384 days. Many cardiovascular benefits of dietary change are believed to take one to two years or more to appear, leading critics to argue that the study ended too soon to detect meaningful effects (14). Like the Sydney trial, it also used partially hydrogenated oils, introducing trans fats as a potential confounding factor.

The “Core” Trials and the LDL Connection

Instead of relying on these contested historical datasets, health organizations emphasize evidence from “core” randomized controlled trials that met rigorous design criteria: adequate duration (greater than two years), good adherence, and freedom from major confounders like trans fats.

A meta-analysis of four such trials, including the Oslo Diet-Heart Study and the Veterans Administration trial, demonstrated that replacing saturated fat with polyunsaturated vegetable oil reduced coronary heart disease (CHD) events by 29% (14). This reduction is comparable to the benefits achieved through statin therapy, which reinforced the diet-heart hypothesis. Additionally, a 2020 Cochrane systematic review supports this stance, finding that across 15 randomized trials involving approximately 59,000 participants, reducing saturated fat for at least two years reduced the risk of combined cardiovascular events by 21% (15). This protection is mechanistically linked to cholesterol. The “LDL theory” suggests that saturated fat raises LDL cholesterol, a well-established causal mediator of atherosclerosis (14). Meta-regression analyses indicate that trials achieving greater reductions in serum cholesterol saw greater reductions in cardiovascular events, suggesting a dose-response relationship that validates the focus on LDL lowering (15).

Seed Oils and Inflammation – Just a Myth?

A common counter-argument to the use of vegetable oils is the concern that linoleic acid (the primary omega-6 PUFA) promotes inflammation and increases coronary heart disease risk. However, Farvid et al. note that this speculation is “not supported by randomized controlled feeding studies,” which found that dietary intake of linoleic acid did not increase inflammatory markers such as C-reactive protein or cytokines (6). Furthermore, observational data involving 310,602 individuals show an inverse association between linoleic acid intake and heart disease risk (6). When comparing the highest category of intake to the lowest, dietary linoleic acid was associated with a 15% lower risk of coronary heart disease events and a 21% lower risk of coronary heart disease deaths (6). Dose-response analyses indicated a linear relationship; a 5% increase in energy from linoleic acid replacing saturated fat was associated with a 9% lower risk of coronary heart disease events and a 13% lower risk of coronary heart disease deaths (6). These data support current recommendations to replace saturated fat with polyunsaturated fat for the primary prevention of coronary heart disease.

Policy Implications

Based on this body of evidence, the Uncompromised Dietary Guidelines for Americans, 2025–2030, a report released by the Center for Science in the Public Interest and the Center for Biological Diversity, maintains that saturated fat should account for less than 10% of daily calories starting at age two. The report explicitly advises replacing food sources of saturated fat (like butter and beef tallow) with sources of polyunsaturated and monounsaturated fat (such as nuts, seeds, and non-tropical vegetable oils). By rejecting the new administration’s push toward animal fats, these organizations argue they are defending public health against “harmful guidance” that contradicts established science (4, 5).

VII. Side-by-Side Policy Comparison: 2020–2025 vs. 2025–2030

Now that we’ve familiarized ourselves with the logic and data that both sides if the debate have used to make their case for National policy, let’s directly compare, point-by-point, the major differences between the previous Dietary Guidelines for Americans (2020-2025) and the newest version (2025-2030). The major differences in policy focus are detailed below:

1. Overarching Philosophy and Framework

• • 2020–2025: The central theme was “Make Every Bite Count,” emphasizing dietary patterns across the lifespan with a specific focus on cultural customization and health equity (2).

• • 2025–2030: The central message is “Eat Real Food” and “Make America Healthy Again.” The administration rejected the 2025 DGAC’s report because it evaluated science through a “health equity lens.” Instead, the new policy asserts that science should be “policy-neutral” and focuses on metabolic dysfunction and chronic disease reversal (3, 8)

2. Saturated Fat and Dairy

• • 2020–2025: Recommended limiting saturated fat to less than 10% of daily calories starting at age 2. It explicitly advised consuming “fat-free or low-fat milk, yogurt, and cheese” (2).

• • 2025–2030: Adopts a “neutral stance” on saturated fat, stating that lowering it below current averages has not been proven to reduce mortality. It recommends full-fat dairy (whole milk, full-fat yogurt) as an excellent source of nutrients, removing the preference for low-fat options. They maintain the 10% limit on saturated fat. However, the focus is on limiting saturated fats found in highly processed foods rather than whole foods like meat or dairy (3, 8).

3. Food Processing and “Real Food”

• • 2020–2025: Focused on “nutrient-dense” choices versus “typical” choices, defining nutrient density by the absence of added sugar, sodium, and saturated fat. It did not explicitly categorize foods based on industrial processing methods (2).

• • 2025–2030: Introduces a strict distinction between “minimally processed” foods and “highly processed” foods. It defines the latter as containing extracted ingredients (refined starches/oils) and chemical additives. The policy advises avoiding highly processed foods entirely, citing them as a driver of chronic disease (3, 8).

4. Protein Targets and Sources

• • 2020–2025: Recommended a variety of protein foods (lean meats, poultry, eggs, seafood, beans, peas, lentils, nuts, seeds, and soy products) generally within the Recommended Dietary Allowance of 0.8g/kg (2).

• • 2025–2030: Explicitly aims to “end the war on protein,” recommending significantly higher intake targets of 1.2–1.6 grams per kilogram of body weight. It prioritizes “high-quality” animal-sourced proteins (meat, poultry, eggs, dairy) alongside plant sources, noting that animal sources provide higher essential amino acid density (3, 8)

5. Carbohydrates and Grains

• • 2020–2025: Recommended that at least half of grains consumed be whole grains, with the other half permitted to be refined (enriched) grains (2).

• • 2025–2030: Takes a stricter stance on refined carbohydrates, labeling refined grains as “sugar in disguise.” It advises significantly reducing processed carbohydrates (white bread, crackers, flour tortillas) and prioritizing fiber-rich whole grains. It also notes that individuals with chronic diseases may benefit from lower-carbohydrate diets (3, 8).

6. Vegetable Oils and Fats

• • 2020–2025: Recommended oils (canola, corn, olive, peanut, safflower, soybean, sunflower) as part of a healthy pattern and advised replacing saturated fats with unsaturated vegetable oils (2).

• • 2025–2030: Highlights concerns regarding “linoleic acid-rich oils” (soybean, corn, cottonseed) and their dominance in the modern diet due to industrial processing. It recommends prioritizing “oils with essential fatty acids like olive oil” (admittedly, a poor choice of words in the guidelines themselves, as olive oil is not a meaningful source of essential fatty acids), but also lists butter and beef tallow as acceptable options for cooking, which were previously discouraged (3, 8).

7. Added Sugars

• • 2020–2025: Recommended limiting added sugars to less than 10% of calories per day for those aged 2 and older (2).

• • 2025–2030: States that “no amount of added sugars… is recommended or considered part of a healthy or nutritious diet.” While it mentions a 10-gram limit per meal, the overall tone is one of avoidance, particularly regarding sugar-sweetened beverages for children (3, 8).

8. Scientific Methodology

• • 2020–2025: Relied on the Scientific Report of the 2020 DGAC, which used data analysis, food pattern modeling, and Nutrition Evidence Systematic Reviews (1, 2)

• • 2025–2030: The administration rejected the 2025 DGAC report due to its “equity” focus. Instead, it commissioned an independent review focused on “causal evidence” (prioritizing Randomized Controlled Trials over observational epidemiology) to create a new Scientific Foundation report (3, 8).

VIII. Synthesis: Interpreting the Reset

The release of the new federal dietary guidelines alongside the alternative “Uncompromised” report marks a clear split in national nutrition policy. On the surface, the debate appears to be about familiar food choices (butter versus oils, animal protein versus plant protein). But when the underlying scientific reports are examined together, it becomes clear that this “reset” is not mainly about specific numbers or foods. It is about what kind of evidence should count as valid science when setting national nutrition policy.

The Nature of the Reset: Procedural and Epistemological

The shift introduced by the new administration is procedural and epistemological, not necessarily rhetorical or numeric. By explicitly rejecting the 2025 Dietary Guidelines Advisory Committee report, the administration departed from the established guideline-development process. It argued that the committee’s use of a “health equity lens” introduced interpretive bias that obscured core physiological questions (8).

In its place, the new Scientific Foundation imposes a hierarchy of evidence that prioritizes causal data from randomized controlled trials over the observational epidemiology that has historically been the linchpin of nutrition policy. This represents a deliberate move away from a public-health framework, which accepts consistent associations across large populations as sufficient for guidance, toward a medicalized model that the administration claims demands clinical proof of cause-and-effect before endorsing or restricting dietary components. Under this framework, even long-standing, internally consistent observational evidence is treated as insufficient. In doing so, the new approach explicitly rejects the traditional interpretation of the legally required “preponderance of scientific evidence” standard. A move that many “experts” are critiquing as the government taking science interpretation into its own hands.

Continuity Beneath the Rhetoric

Despite the rhetorical upheaval and the stark ideological framing that we see on social media, “Make America Healthy Again” versus “Uncompromised Science,” significant continuity remains in the final policy. Most notably, the administration’s published guidelines retain the longstanding limit on saturated fat (less than 10% of calories), even though the administration’s own scientific report argues that such limits are not supported by causal evidence (8).

At the same time, both sides converge on a shared target: ultra-processed foods. Whether framed as a return to “minimally processed, naturally nutrient-dense foods” by the administration or as a critique of “highly processed” foods by its critics, there is broad agreement that food processing, not just macronutrient composition, contributes diet-related disease (although many argue, and rightfully so, that it is the macronutrient composition andcaloric load that drive the harmful effects of processed foods). This convergence signals a broader shift away from strict nutrient reductionism toward food quality and processing, even as disagreements over specific points of emphasis persist.

Persistent Scientific Uncertainty

The divergence between the two sets of guidance reflects genuine and unresolved disputes in nutrition science that the current evidence base cannot fully settle:

• • Mortality vs. Event Reduction: The conflict exposes a gap between reducing cardiovascular events (such as non-fatal heart attacks) and reducing mortality. The new scientific foundation emphasizes historical trials, including the Sydney Diet Heart Study and the Minnesota Coronary Experiment, to argue that replacing saturated fat with linoleic acid may lower cholesterol without extending life (8). In contrast, the opposing position relies on systematic reviews showing reductions in combined cardiovascular events to justify continued restrictions (15).

• • Surrogate Endpoints: The dispute fundamentally challenges the use of LDL cholesterol as a sufficient proxy for health outcomes. The new framework argues that improvements in surrogate markers do not reliably translate into clinical benefit and therefore should not justify population-wide restrictions (9, 13). This directly conflicts with the established view that LDL lowering is causally linked to reduced cardiovascular risk (14).

• • Linoleic Acid Exposure: A further unresolved question concerns the metabolic consequences of modern linoleic acid intake. While the opposing position views polyunsaturated fats as both essential and broadly beneficial, the new scientific foundation argues that contemporary intakes exceed physiological requirements and may promote the formation of toxic lipid hydroperoxides when heated (a hypothesized mechanism of harm that has, admittedly, not been definitively excluded by modern randomized clinical human trials).

Taken together, this shows that the theoretical and political framing of nutrition policy has changed dramatically. The result is a policy environment in which, some would say “radical”, scientific reinterpretations coexist with largely unchanged numeric limits, illuminating the tension between evolving scientific arguments and the inertia of established public-health guidance.

IX. Conclusion: Lessons from a Broken Pattern

The 2025–2030 Dietary Guidelines update is different from any before it. Usually, the government updates nutrition advice slowly, making small tweaks every five years. This time, there was a major break in that pattern. By releasing a new “Scientific Foundation” that rejects the expert committee’s advice, and with the opposition publishing their own “Uncompromised” guidelines, we are left with two competing rulebooks (4, 8). This conflict teaches us three big lessons about how we think about food and health.

1. The Risks of Flipping the Script vs. Slow Change

For decades, the guidelines changed gradually to keep public trust and keep food programs running smoothly. The new administration argued that gradual change was keeping bad science alive, specifically regarding saturated fats and vegetable oils. By hitting the “reset” button, they were able to bring in older data (like the Minnesota Coronary Experiment and Sydney Diet Heart Study) that challenged the idea that lowering cholesterol always saves lives. However, this sudden shift comes with a cost. When official advice flips overnight—telling people to ignore the expert committee, it understandably creates confusion. We now have a situation where doctors and schools have to choose between two different versions of “the truth”. This makes it harder for the average American to know what to believe, potentially damaging trust in science itself (a theme we have heard routinely regardless of policy belief over the years).

2. Focusing on Nutrients vs. Real Food

This debate shows the problem with “nutritionism” – i.e., the obsession with individual nutrients rather than whole foods. For years, policy focused on the math of swapping saturated fat for linoleic acid (polyunsaturated fat).

• • The Conflict: The new “Scientific Foundation” argues that while vegetable oils might lower cholesterol, they might not actually help people live longer, and could even cause harm due to inflammation or oxidation (8). The “Uncompromised” group argues that the standard science still proves these oils are good for the heart (4).

• • The Common Ground: Despite fighting over fat molecules, both sides actually agree on the bigger picture: highly processed foods are a problem. Whether they call it “Make America Healthy Again” or “Uncompromised Science,” both frameworks want Americans to eat real, minimally processed food.

3. We Need Clear Rules for “Proof”

Finally, this cycle proves that we need to agree on what counts as scientific proof. The two sides are playing by different rules.

• • The Medical Model: The new administration demands “causal” evidence (8). They want randomized controlled trials, where you control people’s diets like a drug trial, to prove that a specific food prevents disease. They argue that observational studies (just watching what people eat) are too messy to trust.

• • The Public Health Model: The “traditional experts” argue that you cannot run perfect experiments on human diets for 30 years (4, 14). They rely on the “preponderance of evidence,” which combines shorter experiments with long-term observations of populations.

Until the government defines exactly what kind of evidence is required to make a rule, we will remain in this deadlock. Future guidelines need a transparent standard that balances the rigor of clinical trials with the reality that we cannot test every single food in a lab for a lifetime.

 

References

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2. U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025. 9th Edition. December 2020.

3. U.S. Department of Health and Human Services and U.S. Department of Agriculture. The Scientific Foundation for the Dietary Guidelines for Americans, 2025–2030. 2025.

4. Center for Science in the Public Interest and Center for Biological Diversity. The Uncompromised Dietary Guidelines for Americans, 2025–2030. 2025.

5. Lurie P. New Dietary Guidelines undercut science and sow confusion. Statement. Center for Science in the Public Interest. Updated January 7, 2026.

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8. U.S. Department of Health and Human Services and U.S. Department of Agriculture. The Scientific Foundation for the Dietary Guidelines for Americans, 2025–2030. 2025.

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10. Nicholl A, Deering KE, Evelegh K, et al. Whole-fat dairy products do not adversely affect adiposity or cardiometabolic risk factors in children in the Milky Way Study: a double-blind randomized controlled pilot study. Am J Clin Nutr. 2021;114:2025–2042.

11. Frantz ID Jr, Dawson EA, Ashman PL, et al. Test of effect of lipid lowering by diet on cardiovascular risk. The Minnesota Coronary Survey. Arteriosclerosis. 1989;9:129–35.

12. Woodhill JM, Palmer AJ, Leelarthaepin B, McGilchrist C, Blacket RB. Low fat, low cholesterol diet in secondary prevention of coronary heart disease. Adv Exp Med Biol. 1978;109:317–30.

13. Ramsden CE, Zamora D, Leelarthaepin B, et al. Use of dietary linoleic acid for secondary prevention of coronary heart disease and death: evaluation of recovered data from the Sydney Diet Heart Study and updated meta-analysis. BMJ. 2013;346:e8707.

14. Sacks FM, Lichtenstein AH, Wu JHY, et al. Dietary Fats and Cardiovascular Disease: A Presidential Advisory From the American Heart Association. Circulation. 2017;136:e1–e23.

15. Hooper L, Martin N, Jimoh OF, Kirk C, Foster E, Abdelhamid AS. Reduction in saturated fat intake for cardiovascular disease. Cochrane Database of Systematic Reviews. 2020, Issue 5. Art. No.: CD011737.