Dietary change is obviously needed but current strategies are inadequate. Below are some of the main problems plaguing the dietary guidelines.
The current dietary guidelines should be seen as a failed policy. Despite decades of implementation, they have not achieved their primary goal of improving public health. Instead, the rise in obesity and cardiometabolic illnesses has accelerated, often in parallel with the widespread adoption of these recommendations. This disconnect between intent and outcome raises serious questions about their effectiveness and underlying science. Some critics even suggest that dietary guidelines have not only failed to achieve their objectives but may have inadvertently worsened public health. Critics call for a complete reevaluation of the process, emphasizing transparency, diversity of opinion, and evidence-based decision-making to create more effective and adaptive nutrition policies.
- Bias and conflicts of interest
While defenders of the guidelines emphasize their rigor and transparency, critics argue they are shaped by entrenched biases. By emphasizing low-fat, low-cholesterol, and high-fibre options, the guidelines paved the way for the production and consumption of highly processed foods rich in refined carbohydrates and with added fibres and seed oils to create a health halo. Some critics have even accused the food industry of shaping recommendations through research funding, sponsorships, and lobbying. Various governmental nutrition advisers are indeed known to be paid by some of the leading food multinationals, potentially distorting the validity of nutritional recommendations due to major conflicts of interest, as has been shown for the UK [Borland 2024]. The situation in the US seems at least equally problematic [Mialon et al. 2022], also due to the USDA's alliance with food corporations as ‘strategic partners' [Nutrition Coalition]. By emphasizing low-fat and low-cholesterol options, the dietary guidelines encouraged the production and consumption of highly processed foods rich in sugar and refined carbohydrates.
- Low-certainty evidence and overstated claims
The way dietary advice has been constructed and practiced in the US since the 1980s has been criticized as 'untrustworthy', lacking sufficiently strong evidence and rigor [Guyatt 2019; Johnston 2019]. For instance, several severe methodological quality and reporting problems were present in systematic reviews informing the 2020–2025 Dietary Guidelines for Americans [Bodnaruc et al. 2025].
Critics claim the process relies too heavily on consensus-based science. The slow incorporation of new evidence and the exclusion of dissenting scientific voices have hindered meaningful reform. Critics argue that the guidelines prioritize maintaining consistency with past advice over adopting recommendations based on emerging, rigorous science. This resistance to change perpetuates outdated advice, preventing progress in addressing modern health challenges. As a result, nutritional epidemiology of chronic disease has commonly been used to formulate implausible conclusions and overstate the evidence [Cofield et al. 2010; Schoenfeld & Ioannidis 2013; Ioannidis 2018].
For a criticism of the scientific evidence underpinning advice for the restriction of animal source foods (and red meat in particular), see elsewhere on this website. Similarly, advice to restrict sodium intake beyond current average intake levels is poorly supported by the evidence, especially for normotensive people [Graudal et al. 2017; Graudal & Jürgens 2018; Mente et al. 2021; Ezekowitz et al. 2022]. Moreover, some commonly claimed protective effects on specific health outcomes are not to be taken for granted, as may be the case for calorie counting [Fernandes et al. 2019], 'Mediterranean' dieting [Rees et al. 2019], fruits and vegetables [Young et al. 2002; Møller et al. 2003; Crane et al. 2011; Kaiser at al. 2014; McEvoy et al. 2015; Duthie et al. 2018; Peluso et al. 2018; WCRF 2018, Key et al. 2020; Alami et al. 2022], whole-grains and fiber [Ho et al. 2012; Peery et al. 2012; Yang et al. 2012; Clark & Slavin 2013; Kelly et al. 2017; Guo et al. 2020; Marshall et al. 2020; Sadeghi et al. 2020], intake of antioxidants [Huggins & Simsolo 2021; Luo et al. 2021], or polyunsaturated fat [Ramsden et al. 2013; Hamley et al. 2017; Hanson et al. 2020]. These effects are either non-existent or likely too small to be a game changer in a context of Western diets and lifestyles.
The guidelines have been criticized for their one-size-fits-all approach, failing to account for individual variability in dietary needs and cultural differences. By focusing on generalized recommendations, they may alienate or mislead populations whose nutritional requirements do not align with the prescribed norms.
Every body is different in the way it reacts to a given diet, with respect to nutritional needs, metabolic responses, endocrine regulation, etc. Overruling this diversity with monolithic approaches to dietary formulation may undermine the body's ability to self-select foods. For instance, a person's glucose response to duplicate meals can be very variable, even under controlled conditions [Hengist et al. 2024]. Also, whether or not one can adapt successfully to a vegetarian diet depends on genetic differences, for instance related to genes encoding functions in lipid metabolism and brain function [Yaseen et al. 2023].
The conventional “calories in, calories out” approach for weight management, for instance, is profoundly problematic as it overlooks real-life complexities. Such model fails to address the existence of different body types (ectomorph, mesomorph, and endomorph) and variability in individual environmental and lifestyle factors (exercise, stress, etc.), variability in gut microbiota, genetic polymorphisms, epigenetic changes, and overall metabolic and hormonal variability (insulin sensitivity, etc.), fluctuations, and adaptive responses (adaptive thermogenesis, etc.) [Theodorakis et al. 2024]. Additionally, accurately calculating caloric needs is impossible due to the large margin of variability allowed on food energy labels (fluctuating by up to 20% according to regulatory standards, but even reaching discrepancies as high as 60% in practice) [Theodorakis et al. 2024]. The premise that energy density of a meal leads to a high energy intake is therefore flawed, as the relationship between both is non-linear whereas humans are sensitive enough to the energy content of their meals to be able to adjust (and maybe even overcompensate) the meal size accordingly [Flynn et al. 2022].
In the case of low-certainty evidence, guideline recommendations should be weak, conditional, and more pluralistic, based on the health-related values and preferences of the guideline users, a component of evidence-based practice that is regularly neglected.
- Dietary guidelines are arrogant and exclusive
Since official health bodies - and the advice they promote - represent expert opinion, this readily results in appeal to authority, hinders the debate on what constitutes an 'optimal' diet [see elsewhere], and suppresses and marginalizes dissident opinion. Alternative perspectives, such as higher-fat or low-carbohydrate diets, are often excluded, creating a narrow framework of accepted thought. Dietary guidelines may have to be seen as a class-based construct that merely tells us what already healthy people (white, educated, middle-class professionals) believe a 'healthy diet' is [Hite 2018]. Indeed, people of higher socio-economic status, which are more motivated, educated, and better-resourced, typically consume more whole grains, lean meats, fish, low-fat dairy products, and fresh vegetables and fruit [Darmon & Drewnowski 2008; Mathieu-Bohl & Wendner 2020]. Importantly, this usually neglected relationship can create a ‘healthy user bias’, confounding epidemiologic relations between diet quality and health outcomes [Darmon & Drewnowski 2008]. This could cast doubt on which foods are truly healthful or harmful, due to a misleading statistical association with unmeasured socio-economic (lifestyle) factors. It may explain why striking and contradictory differences are often seen when comparing US-based cohorts with ones that are either global (cf. PURE study) or situated in other regions, especially with respect to the health outcomes of saturated fat, red meat, and fibre.
The privileged position of 'healthy diets' can be patronizing, pushing Western nutrition theory upon cultural minorities [Best & Ward 2020; Katz-Rosene 2020], and thereby neglecting 'complexities of nourishment that are at the heart of kinship, social life, and caregiving' [Burnett et al. 2020]. The result is often a monolithic 'one-size-fits-all' reductionist approach to food and nutrition [Katz-Rosene 2020], excessively relying on an animal/plant divide [see elsewhere].
'Preventive' public health nutrition displays all three signs of arrogance, being (1) aggressively assertive (pursuing symptomless individuals in the general citizenry), (2) presumptuous (confident it does more good than harm), and (3) overbearing (attacking those who question the value of its recommendations) [cf. Sackett, 2002]. Health education policies are based on the neoliberal assumption that everyone is responsible and accountable for their own health by adherence to the norms, so that individuals who are considered ignorant of health measures need to be educated on, for instance, calorie counting, the harms of fat, or the benefits of fibre [Fixsen 2024]. Yet, while public health policies stress individual responsibility, deregulated markets wich erode traditional ways of eating are promoting disordered consumption patterns that conflict with self-care [Pirie 2016; Fixsen 2024].
Taken together, dietary guidelines describe opinion but fail to provide meaningful information about true diet-chronic disease relationships. Some argue that it may as well be wiser to ignore them altogether [Marantz et al. 2008].This is not to be considered as anodyne; in a biopolitical context, public health interventions can have serious ethical repercussions on individual responsibility and freedom, cause iatrogenic harm, and affect societal well-being [Mayes & Thompson 2015].
This is, for instance, the case for the 'Nunavik food guide', whereby a Mediterranean-style pyramid, rebranded as an igloo-shaped model, is used to 'reflect current issues in nutrition and to meet the needs' of the local Inuit [NRBHSS 2020]. Meat, fish, and fat, that were once at the heart of historical arctic diets [see elsewhere], have been strongly de-emphasized to the benefit of previously irrelevant foods such as vegetables, exotic fruits, (breakfast) cereals, and milk. Similarly, the Australian 'Aboriginal and Torres Strait Islander Guide to Healthy Eating' is superficially framed as a traditional dietary model but is once more based on Western nutritional dogma and at odds with indigenous eating habits [NHMRC 2015]. Meanwhile, the fact that meat-heavy ancestral diets sustain good health are ignored. For instance, the Masai are on a long continued diet of exclusively meat and milk but display little evidence for atherosclerotic heart disease [Mann et al. 1964], despite atherosclerosis and intimal thickening [Mann et al. 1972].