Dietary Guidelines: No Concluding Evidence?!

Dr Jedha, Host

Hello wonderful people, it’s Dr Jedha here and thanks for joining me for another dive into dietary guidelines where we’re going to investigate and chat about some very interesting things. 

01:10

The U.S. Dietary Guidelines have been a cornerstone of public health recommendations since their inception in 1980. These guidelines are supposedly aimed to provide science-based advice on what people should eat to promote health and reduce the risk of chronic diseases. Published every five years, they are influential in shaping school lunch programs, public health campaigns, and even what we see in grocery store advertisements. We also saw these guidelines modelled over into the Standards of Care in Diabetes, which we spoke about recently in episode 62.

Likewise dietary guidelines around the globe tend to be similar, with updates every 5 years or so, and often they resemble similar guidelines to those published in the US, frequently using the American Diabetes Guidelines as a model. 

As we’ll discuss today, these guidelines have remained strikingly consistent, with recommendations to eat a low fat high carbohydrate diet, and as each year passes, there is an increasingly plant-based focus. In fact, despite decades of nutrition research and compelling evidence, the guidelines haven’t shifted much from the original narrative. Why? That’s a question worth exploring.

When the guidelines were first introduced, they were a product of their time. Heart disease rates were identified as being high, and saturated fat was quickly marked as the public enemy. This advice, deeply rooted in inaccurate observational studies, became the cornerstone of dietary policy. And the solution that followed those dietary guidelines was to reduce fat and cholesterol intake. Subsequently, those nutrients have been replaced with carbohydrates, and high amounts of sugar and empty carbs. 

03:15

Fast-forward to 2025, and the core message of the dietary guidelines remains unchanged: limit saturated fat to less than 10% of daily calories, focus on grains, fruits, and vegetables, and minimize red and processed meats. But what’s fascinating is how each iteration of the guidelines doubles down on these recommendations, even as the science supporting them remains weak or even worse, nonexistent.

The latest version of the guidelines has made an even stronger push for a plant-based diet. Recommendations now include an “Eat Healthy Your Way” dietary pattern that emphasizes beans, lentils, and legumes over traditional protein sources like meat and eggs. In fact, the scientific committee recommends foods like beans, lentils, and legumes be moved to the top of the protein category, with red meat and poultry shuffled to the bottom. This is absolutely absurd, the reasons of which we’ll explore later in the podcast.

Additionally, the guidelines maintain their cap on saturated fat, despite mounting evidence—or lack thereof—suggesting no link between saturated fat intake and cardiovascular disease. 

This is highly concerning as there are massive consequences of sticking to the status quo. Think about it: the Western World has largely followed the dietary guidelines for a number of decades now. Fat consumption may have decreased, while carbohydrate and sugar intake has risen exponentially. Do we see better health outcomes? No. Quite the opposite in fact. We’ve seen astonishing rates of obesity, type 2 diabetes, and metabolic syndrome, these health conditions have skyrocketed. Could it be that the dietary advice itself is flawed?

When we look to evidence surrounding these health conditions, in recent years, systematic reviews and randomized controlled trials have failed to provide compelling evidence that the low-fat, high-carbohydrate dietary model prevents chronic diseases, and we certainly know it does nothing to treat them. Yet still, the guidelines persist.

One particularly concerning aspect of the 2025 guidelines is the continued reliance on outdated assumptions. For example, the chapter on saturated fat in the scientific report acknowledges “no association” and a wide range of inconclusive statements in key areas like cardiovascular outcomes—but the cap on saturated fat remains. It’s as if the guidelines are stuck in a time loop, repeating advice that’s become increasingly irrelevant.

Why does all this matter? Well, the implications of clinging to outdated guidelines are enormous. These recommendations influence everything, affecting millions of people’s eating habits. If science has moved on, shouldn’t the guidelines follow?

We’d all hope that would be the case but….

Listen in, because we’re going to dive deeper and critically examine the evidence—or lack thereof—that supports the U.S. Dietary Guidelines, and subsequent guidelines around the world that usually follow suit. And we’ll ask the tough questions: Why are they so resistant to change? And what does this mean for you and your health? 

06:55

One of the first areas I want to dive into is the huge evidence gap on recommendations for dietary fats. In fact, it’s a canyon of empty evidence and equally empty advice. 

For numerous decades, the U.S. Dietary Guidelines have placed significant emphasis on limiting dietary fat, particularly saturated fat, as a means to reduce the risk of cardiovascular disease. We’ve all heard this time and time again throughout the ages—fat is bad, don’t eat too much saturated fat, margarine is better than butter, fat will clog your arteries, eating too much fat makes you fat, low fat foods are healthier, cholesterol in foods will raise cholesterol levels, eating fat will raise cholesterol levels, vegetable oils are healthy, fat-free milk is better than whole milk, and the list goes on. 

Of course it’s no wonder we all think it’s an absolute truth, set in stone, based on solid proven evidence, right? We’ve heard it for so long that these types of things have shaped public perception. These narratives are widely accepted, it’s what we all think. That’s what the whole entire world has accepted, as “truth.”

However, this is not the case. The evidence underpinning these recommendations remains weak and inconsistent, a fact even acknowledged by the Scientific Report that is meant to back the 2025 dietary guidelines.

08:28

In the 2025 Scientific Report for the U.S Dietary Guidelines, the ongoing cap on saturated fat, which restricts intake to less than 10% of daily calories, remains. In addition, the Committee now ‘clarify’ that this limitation on saturated fat intake should start at 2 years of age.

In the opening paragraph, the Advisory Committee states, and I quote: “Guidance has been informed by a large body of consistent, high-quality evidence on the role of saturated fat in the development and progression of cardiovascular disease.”

In the report they present a rave about the evidence, then it goes into specific questions and the conclusive statements to those questions. The first question presented was: What is the relationship between food sources of saturated fat consumed and risk of cardiovascular disease?

Firstly they list conclusion statements to identify whether there is decreased risk of cardiovascular disease, the risk when food sources of saturated fat are substituted or replaced. The Committee clearly states here that most of the evidence statements are based on limited to moderate evidence. In fact, the only evidence they claimed was strong was when they compared butter to plant-based oils and spreads.

The evidence graded as strong was that replacing butter with plant-based oils and spreads decreases LDL-cholesterol but does not affect HDL cholesterol or triglyceride levels. The second statement on butter says there is limited evidence that replacing butter with plant-based oils and spreads makes any difference to cardiovascular disease. 

If you haven’t listened to episode 42 on understanding cholesterol, please do. Because here’s the thing: it doesn’t matter if plant-based oils and spreads decrease LDL-cholesterol. LDL cholesterol is not bad and lowering LDL-cholesterol independent of anything else is not a health benefit. Just lowering LDL-cholesterol is not an indicator that is directly associated with cardiovascular disease. In fact, high triglycerides are more directly associated with cardiovascular disease than LDL and butter has no effect on triglyceride levels or HDL cholesterol, as clearly indicated by the report. Likewise, consuming plant-based oils and spreads over butter makes no difference to cardiovascular disease risk overall, so what is strong about that evidence? 

The answer is, nothing. But, they are trying to claim there is strong evidence that plant-based oils and spreads decrease cardiovascular disease. That’s not what the evidence suggests.

Next the report lists a whole bunch of conclusion statements that identified no difference in cardiovascular risk. Again, The Committee clearly states here that most of the evidence statements are based on limited to moderate evidence. Now hang on a sec, didn’t the opening statement say that guidance on saturated fat has been informed by a large body of consistent, high-quality evidence. 

Yes, it did. 

Limited to moderate evidence is not strong, consistent, high-quality evidence. But it gets worse. 

Further in the chapter they list relationships where conclusion statements could NOT be drawn, in relation to adults. 

To summarize, in terms of cardiovascular risk, there is no evidence to conclude that high fat dairy should be replaced with low fat dairy. There is no evidence to conclude different amounts of saturated fat or any amount of saturated fats in red meats are problematic, similarly for white meats. There is no evidence to conclude processed or unprocessed meats, including red and white meats, increase risk of cardiovascular disease. There is no evidence to conclude that plant sources of saturated fat like palm oil, coconut oil and cocoa butter increase risk in comparison to meat. There is no evidence to conclude that plant-based foods higher in saturated fat are better than meat consumption. 

The next section provides relationships where conclusion statements could not be drawn, for children and adolescents. To summarize, there is no evidence to conclude that children should limit dairy sources of saturated fat. There is no evidence to conclude that children or adolescents should limit meat sources of saturated fat. 

The closing statement provided in the report was, and I quote:  “For children and adolescents, no conclusion statements could be drawn about the relationship between consumption of food sources of saturated fat and risk of cardiovascular disease because there was not enough evidence.”

So basically, the Committee ‘clarifies’ that the limitation on saturated fat to 10% of daily energy intake should start at 2 years of age—based on zero evidence. Later, they again go on to claim that processed margarine is better than butter, which they state is strong evidence. We’ve already shown it’s not. And overall, they base their claims on evidence graded as moderate, which are statements based on bad population studies, which cannot draw any conclusions. Or when they say there is limited evidence, which is a lot, it’s basically a statement that there is no evidence at all. 

Overall, the advisory committee found no consistent associations between saturated fat intake and cardiovascular outcomes. There is certainly no strong, consistent, high-quality evidence, as suggested in the opening statement. Quite the contrary, the report explicitly highlights that many relationships “for which conclusion statements could not be drawn,” as quite simply, there is no evidence to suggest saturated fats are “bad.” If the evidence is inconclusive or nonexistent, why does this guideline persist?

15:12

Let’s talk about another thing, this ongoing shift toward plant-based eating. 

The 2025 Scientific Report places an even stronger emphasis on plant-based dietary patterns than ever before. While the inclusion of more fruits, vegetables, and legumes is undeniably a positive step for most people, as we know most people simply do not eat enough healthy foods, period. But… the narrative around replacing animal-based proteins with plant-based alternatives raises critical questions about nutrient density and the underlying evidence for these recommendations.

One of the most notable changes suggested by the Committee is the reordering of protein food subgroups. They suggest that beans, lentils, and legumes should now be listed first, followed by nuts, seeds and soy products, with animal proteins such as seafood, poultry, and red meat moved to the bottom of the list. 

This prioritization sends a clear message: plant-based proteins are preferred over their animal-based counterparts. But, where is the evidence for that?

Again, there isn’t any. 

I enjoy plant-based proteins and understand that encouraging plant-based eating has its merits. But prioritizing it to the exclusion of nutrient-dense animal-based foods could have unintended consequences. 

Animal proteins are complete sources of protein that are highly bioavailable to the body—meaning we absorb this quality protein readily. Plant-based proteins are predominantly carbohydrates foods, they are rich in calories, they are not complete proteins and they lack bioavailability for many nutrients. 

Animal proteins like eggs, seafood, and meats provide high-quality protein, essential fatty acids, and bioavailable nutrients such as B12, zinc, and iodine. These nutrients are essential for everyone and they are critical for many life stages, particularly for children, pregnant women and older adults.

By shifting the most nutrient-dense protein sources to the bottom of the protein hierarchy, the guidelines risk creating a perception that they are unhealthy or less important. In addition, they encourage people to eat more carbohydrates, without education about the quality of protein versus carbohydrates in those foods. That’s not a good move. These types of recommendations have the potential to drive our disease epidemic into more of a crisis, not fix it. 

This could lead to nutrient deficiencies in populations that already struggle with meeting dietary recommendations, raise blood glucose in those already struggling, worsen insulin resistance and the list goes on. THere just can’t be a benefit in telling people to limit quality nutrient dense protein as protein is one of the most essential nutrients we need. 

19:02

With what we’ve covered so far, we’ve only touched the tip of the iceberg but the question is, why does this low-fat paradigm persist? 

Yes it would be difficult to change. Changing dietary guidelines would require acknowledging past missteps and re-educating both the public and healthcare professionals, a daunting and politically sensitive task. Additionally, decades of public health messaging have ingrained the idea that saturated fat is harmful, making it difficult to shift perceptions even in the face of contradictory evidence.

And let’s not forget the big elephant in the room. The other factor that always plays a role is big food companies. The food ‘industry’ loves the multiple billions of dollars each year that we consumers award them. Likewise, the pharmaceutical companies make billions from keeping us sick, and there are vested interests here on many systemic levels. 

Years ago, these relational conflicts were glaringly obvious but people never questioned them. Now, we try to sweep the vested interests under the carpet and hide them away like they don’t exist, but of course they do. 

The report indicated that individual conflicts of interests for individual members of the Committee or those involved in the report were not listed, but instead the conflicts were listed collectively. It took me a while to find the list of vested interests related to the scientific report and the committee involved, it certainly wasn’t easy to find and was on the website separately not in the actual report, but I tracked it down. And of course, there are multiple conflicts of interest. These included people on the committee being provided with grants or contracts from several pharmaceutical companies, several food companies, and various health institutions. It included people on the committee receiving consulting fees from several pharmaceutical companies and food companies, along with health institutions. And Beyond Meat, a vegan plant-based meat company, was listed as being a financial or non financial interest. While conflicts of interest aren’t meant to make an impact on outcomes, and sometimes they don’t. But the reality is, often they do, which is an unfortunate truth. 

21:39

So where does that leave us?

Well, the resistance to change is not without consequences. By clinging to outdated recommendations, the guidelines fail to reflect the nuances of modern nutrition science. For example, the context in which saturated fat is consumed—such as in whole, minimally processed foods versus ultra-processed foods—matters greatly for health outcomes, a distinction that the current guidelines largely overlook. In fact, there wasn’t much emphasis at all on the consequences of people eating ultra processed food.  

The emphasis on reducing saturated fat often overshadows more pressing dietary concerns, such as the overconsumption of added sugars and ultra-processed foods. By failing to prioritize these issues, the guidelines miss an opportunity to address the true drivers of poor metabolic health. Unfortunately however, for the next 5 years, clinging to outdated dogma is what the Committee has decided to do, yet again, regardless of what the evidence actually suggests.  

The thing we fear the most is that these guidelines shape everything from food labeling to dietary advice in clinical settings. When the evidence base is this shaky, these policies risk promoting ineffective or even counterproductive strategies for preventing chronic diseases like cardiovascular disease and type 2 diabetes, and in the future we’re unlikely to see progress but quite the opposite in terms of disease statistics, as we’ll be driving higher consumption of low fat, high sugar and high carbohydrate foods, which are detrimental for metabolic health and lead to increases in prediabetes and type 2 diabetes, which we’re now seeing in more children as well.

This stuff all really frustrates me and I could go on and on but I think you get the point so let’s wrap up today’s discussion with an empowering note.

While the 2025 Dietary Guidelines may seem like a daunting barrier, the power to shape your health remains in your hands. You’re not confined by outdated recommendations or industry-driven narratives. The truth is, with access to the right information and a willingness to challenge the status quo, you can make informed, intentional choices that align with your health goals.

You are capable of reclaiming your health by focusing on what truly matters: eating nutrient-dense, whole foods, avoiding ultra-processed options, and listening to your body’s unique needs. 

By understanding the truth, together, we can rise above misleading guidelines and create a future where science and health—not profits—guide our decisions.

Thank you for joining me today, and remember that knowledge is power, but action transforms. 

Keep asking questions, seeking evidence, and trusting yourself to make the choices that empower you and your health. 

Until next time, take care, and keep thriving!

Dr Jedha, over and out.