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Introduction
It has become common rhetoric for those promoting various types of diets to suggest that dietary guidelines published by government departments are at best, unhealthy, or at worst, causative in driving obesity and chronic disease in the population.
While different countries and organizations produce their own guidelines, with slight differences, most of the conversation has focused on the Dietary Guidelines for Americans, that are created by the USDA.
Often the claims is that following these guidelines actually harms health, rather than promote it. And the guidelines are simply a result of industry forces, long-standing bias, and shoddy science.
But do these claims hold up to scrutiny? In this episode Alan and Danny look at some of the arguments put foward, and take a look at the science underpinning dietary guidelines in a number of countries.
Related resources
Podcast Episodes:
- 378: Nutritional Epidemiology
- 386: Deirdre Tobias, ScD – Study Design, Diet Collection Methods and Nutrition Epidemiology
- 428: Food Environments
Other Content:
- Review: Montani, 2021- Ancel Keys: The legacy of a giant in physiology, nutrition, and public health
- Lecture: Alan Flanagan – The Seven Countries Study: Facts Over Fiction (subscription required)
- [0.00.46]Examples of arguments put forward stating that it’s not healthy to follow dietary guidelines
- [0.11.50]History of the development of guidelines in the US & narratives around Ancel Keys
- [0.22.50]Misrepresentation of what the guidelines say
- [0.29.49]What are actually in the current Dietary Guidelines for Americans?
- [0.32.10]Changes to guidelines over time
- [0.35.05]Other countries’ guidelines: UK, Canada, Nordic countries
- [0.39.50]Investigating the rise in obesity/disease prevalence with the roll out of the guidelines
- [0.55.34]Do people follow the guidelines?
- [0.59.01]The negative role of the food industry
- [1.02.50]Potential issues with dietary guidelines
- [1.10.18]Key Ideas segment
The Hosts
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Dr. Alan Flanagan has a PhD in nutrition from the University of Surrey, where his doctoral research focused on circadian rhythms, feeding, and chrononutrition.
This work was based on human intervention trials. He also has a Masters in Nutritional Medicine from the same institution.
Dr. Flanagan is a regular co-host of Sigma Nutrition Radio. He also produces written content for Sigma Nutrition, as part of his role as Research Communication Officer.
Danny Lennon has a master’s degree (MSc.) in Nutritional Sciences from University College Cork, and he is the founder of Sigma Nutrition.
Danny is currently a member of the Advisory Board of the Sports Nutrition Association, the global regulatory body responsible for the standardisation of best practice in the sports nutrition profession.
Key Ideas
#1: Twisting of Narratives & Use of Partial Truths
Use of narrative the evokes emotion, has some aspect of truth to it, which is then used to get to conclusions that are just false…
Do guidelines typically recommend limits on fat intake? Sure; across guidelines, fat intakes of between 20 – 40% are generally suggested. But as we discussed, this is a function of aiming to keep saturated fat low, rather than dietary fat being unhealthy.
As an example, from the Nordic Nutrition Recommendations: “The current scientific evidence used to set recommended intake ranges is strong for certain sub-categories of macronutrients but less so for the intake of total carbohydrates and fat. The scientific evidence for the fatty acid composition in the diet is stronger than for the total fat intake with respect to development of chronic diseases such as coronary heart disease, type-2 diabetes, and certain cancers.”
But then the dietary fat limit is used to justify odd claims like: “they want you to consume sugar instead”. Often there is mention of sugar industry lobbying, etc.
But what guidelines recommend more added sugar? Where can this be found?
As Alan noted in the episode, this is conflating guidelines with what the food industry has done. So are there zero-fat yogurts with added sugar? Sure. But no guideline recommends people to eat an excess of added sugar.
#2: Revisionist Framing & Outright False Claims
The revisionist nature of this. I won’t recap all Alan has said here, and in other episodes on the Ancel Keys demonisation.
See this review for more context: Montani, 2021- Ancel Keys: The legacy of a giant in physiology, nutrition, and public health
#3: Are some “anti-dietary guidelines” arguments valid?
- COIs: In relation to the US, there is a conflict of interests due to the USDA having a role in developing nutrition guidelines whilst also being tasked with helping the agricultural industry.
- Food industry role: The role of the food industry in shaping population intake is a problem
- Original recommendations are too harsh on dietary fat: Perhaps, but since then more nuance has been added (e.g. focus on sat fat; while total fat and cholesterol are less of a focus).
- Sugar limits still too high: This is a fair point, but some committees advising government guidelines already discuss this. For example, in the UK, the Scientific Advisory Committee on Nutrition (SACN) advice is to limit free sugars to no more than 5% of daily calorie intake.
