WHO Europe outlines healthy and sustainable diets workstream

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The World Health Organization (WHO) European Office for the Prevention and Control of Noncommunicable Diseases have released a fact sheet on their workstreams around healthy and sustainable diets. This work is intended to guide European national policy on shifts towards more sustainable diets.

Many public health authorities and governments use WHO recommendations as a basis to guide decision making. The outlined workstreams indicate WHO’s interest in nutrient profiling, processed foods and beverages, digital marketing and sustainable food systems. Below are some details on individual workstreams:

  • Food profiling model for healthy and sustainable diets

Current food profiling tools (that score foods on nutritional and environmental factors) will be reviewed and used to develop a new standardised tool. This tool will then be used to inform the creation of sustainable food labelling.

  • Data platform for modelling healthy and sustainable dietary patterns

An open-access data platform that will allow governments to assess their national dietary intake data and model diets to meet local nutrition needs and sustainability goals.

  • Guidelines on ultra-processed plant-based foods

Investigating the nutritional composition of ultra-processed plant-based foods (such as vegan burgers) sold in retail and restaurants. This will be used to inform guidelines on ultra-processed plant-based food intake.

  • Healthy digital food environments

An online platform, called FoodDB, that compiles nutrition data from online food retailers, with the intent of making healthy online food choices easier.

These projects will have important ramifications for the treatment of sustainable nutrition by European authorities. Quantifying the nutritional composition of novel foods is essential in understanding their benefits and risks. It is to be hoped that this project will extend to consideration of the bioavailability of the nutrients in the novel foods.

The greater availability of nutritional data to researchers and policy-makers should allow for more evidence-based decisions on food policy shifts. However, the challenge of creating food profiling tools that can fully capture the nutritional and environmental aspects of different foods is clear: nutrition and environmental impacts are very broad topics, and unifying data from both of these fields in order to compare different foods directly will not be straightforward.

Moreover, there is a difference between healthy, sustainable diets and a globally sustainable food system. A diet that meets health, nutrition and sustainability goals for an individual may not be feasible for feeding the global population. For example, increasing the production of a certain food that contributes to one individual’s healthy, sustainable diet may result in less sustainable production of that food. It is essential to consider both what is healthy for individuals and what the global food system can sustainably produce for the global population.

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Dairy in a low-cholesterol diet

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A recent study on dairy’s role in cardiometabolic health has added further nuance to the topic by indicating the different outcomes total dairy and individual dairy products have on biomarkers of disease.

Cardiometabolic diseases including cardiovascular disease, diabetes and chronic renal failure are now the number one cause of death in our aging population. The main cause of these diseases is an unhealthy lifestyle. A broad range of biomarkers (indicators of a disease that can be found in the blood) have been identified and can be used to determine onset. Some studies have linked dairy intake with increased risk of individuals developing cardiometabolic disease. The present study tested these associations to further understand how dairy products can influence cardiometabolic health by measuring biomarkers.

The cross-sectional study included over 35,000 women aged 50 to 79, spanning 40 clinical centres across the US. Concentrations of 20 different biomarkers were compared.

The key findings were:

  • Lower triglyceride (type of fat associated with cardiometabolic disease) was associated with greater intake of total dairy. This was driven by full-fat dairy products
  • Greater total milk and yoghurt intake were associated with lower concentrations of total cholesterol, while greater butter intake was associated with higher cholesterol concentrations
  • Greater total dairy, total and full-fat cheese and yoghurt were consistently associated with lower concentrations of glucose, insulin and C-reactive protein (all of which are biomarkers of cardiometabolic disease).

These findings do not support conclusions of dairy playing a role in cardiometabolic disease, and more specifically the health benefit for low-fat dairy product varieties over full-fat, as promulgated by some health authorities. The challenge in finding consistent outcomes for the role of dairy in the onset of cardiometabolic disease calls for further research in the area. What has been made obvious is the critical role that nutrition plays in the health of our populations and that individual products, rather than food groups, should be considered.

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Your health is what you eat: the role of nutrition in health

This Thought for Food from Professor and researcher in Health Economics at the University of Sao Paulo, Flavia Mori Sarti, focuses on the importance of healthy diets based on regular intake of fruit and vegetables to maintain health and prevent the onset of noncommunicable diseases (NCDs), alongside the potential impacts on health care costs.

In recent decades, advances in nutrition research have been showing the role of diet in promoting health and preventing diseases. A balanced food consumption pattern that includes diverse types of staples, fruits, vegetables, and protein sources provides the energy, macro- and micronutrients to support healthy lifestyles. The consumption of other bioactive compounds may also help prevent certain chronic NCDs such as type 2 diabetes, dyslipidemias, and cardiovascular diseases.

However, the food consumption patterns of many populations around the world have been changing away from more traditional patterns towards modern diets marked by excessive intake of industrialized foods with high content of sugar, trans-fats and salt. The nutrition transition refers to the process of substitution of foods in natura with industrialized foods in different populations. This is often accompanied by a decrease in physical activities during transport, work and leisure, and an increase in sedentary activities.

The importance of consuming fruits and vegetables

Agriculture remains one of the most important economic activities, generating employment and income for billions of individuals worldwide. There are approximately 250,000 edible plant species known; however, only around 120 species are cultivated for human consumption. In addition, 12 plants and five animal species are responsible for approximately 75% of world food. Yet, plant food sources represent the main source of energy and nutrients, and are the sole contributors to fiber intake in the human diet.

Many health authorities recommend food consumption patterns with increased consumption of fresh fruits and vegetables to ensure sufficient intake of fiber, micronutrients, trace elements and bioactive compounds, also known as phytochemicals.

Dietary guidelines referring to the daily intake of fresh fruits and vegetables seek to promote the supply of nutrients through healthy diets, optimizing body functions and maintaining an individual’s health. Considering variations in cultural habits, several countries and regions publish and update national dietary guidelines based on current nutrition knowledge adapted for their populations (for example, Australia, Brazil, European Union, India, Japan, New Zealand, and the United States).

Nutritional deficiencies, such as a lack of specific vitamins and minerals found at high concentrations in plants, may be prevented through inclusion of diverse fruits and vegetables in daily meals. There is significant evidence that the high consumption of fiber reduces cholesterol and reduces the risk of cardiovascular diseases, diabetes and certain types of cancer. In addition, research on the numerous bioactive compounds that have been identified in plant foods show their contribution to the reduction of risk of NCDs in diverse population groups.

However, not all fruits and vegetables are of equal benefit. The 5-a-day mantra, adopted by authorities in many countries to increase fruit and vegetable consumption, can give the impression that all forms of fruit and vegetables deliver equally positive health consequences. While increased fruit and vegetable consumption is linked to multiple positive health outcomes, it is important to acknowledge the varied nutritional contents of these foods.

For example, there has been much debate on whether fruit juices should count towards achieving intake targets. While fruit juices contain many important micronutrients, they are also a source of sugar while lacking fiber. In developed nations, dietary fruit and vegetable variety is poor, with starchy vegetables making a disproportionately high contribution to vegetable intakes. These foods deliver a high energy intake with low nutrient diversity compared to other vegetables, such as leafy greens. The most desirable increases in fruit and vegetable consumption would be those that deliver high concentrations of micronutrients and fiber without contributing to macronutrient excesses.

Diet-health nexus for reduction of health care costs

Although there is substantial evidence on the protective effects of healthy diets, the consumption of diverse fruits and vegetables in daily diets is usually lower than recommendations in many countries.

The World Health Organization recommendation regarding consumption of fruits and vegetables is to include at least 400 grams per capita per day in the diet. However, according to data from the Food and Agriculture Organization (FAO), only 101 out of 174 countries had sufficient food supply to achieve this recommendation in 2018. Accounting for food waste (approximately 15% to 30% of food supply, depending on the country), the proportion of countries that fulfill the WHO recommendation reduces to approximately 60 out of 174 countries.

On the other hand, 169 out of 174 countries had a food energy supply greater than 2,000 calories per capita per day. Even accounting for food waste, approximately 120 countries still provide excess daily calories for adult individuals with sedentary lifestyles.

Therefore, modern lifestyles lead to a higher prevalence of obesity and related morbidities in many countries. The recent Global Burden of Disease Study 2019 indicated the greatest recorded increase in populations’ exposure to obesity and diabetes was between 1990 and 2019, among other risk factors for early mortality linked with modifiable behaviors. Simultaneously, the low diversity in food consumption patterns provide low intakes of micronutrients and bioactive compounds, characterizing the double burden of diseases, marked by coexistence of undernutrition and obesity related to NCD.

In Brazil, direct costs due to outpatient and inpatient care for treatment of 14 overweight- and obesity-related diseases has been estimated to total US$ 2.1 billion per year between 2008 and 2010. Other estimates pointed to expenditures of approximately 3.45 billion reais (US$ 908 million), attributable to outpatient, inpatient and medication for treatment of hypertension, diabetes and obesity on the national health system in 2018.

A systematic review of literature showed estimates of substantial direct health care costs of obesity and related diseases in 17 studies from developed countries and 6 studies from developing countries. They found that the medical costs associated with obesity and its knock-on effects had been increasing across both the developed and developing world. A previous review indicated that obesity was responsible for approximately 0.7% to 2.8% national health care expenditures in developed and developing countries worldwide. Additionally, individuals diagnosed with obesity usually presented costs 30% higher in comparison with healthy weight individuals due to occurrence of obesity-related NCD.

Conclusion

The reversion of negative nutrition transition trends worldwide depends on changes at individual, social, and policy level: these include gradual modifications of dietary patterns towards greater inclusion of nutrient-dense fruits and vegetables; increased physical activity levels, particularly during transportation and leisure; regulation of food marketing directed at children; adoption of nutrition education strategies; and health promotion actions within primary health care.

The cost-effectiveness of numerous strategies targeting obesity among children, adolescents and adults was assessed through economic evaluation studies in Australia, showing higher effectiveness of actions focusing on lifestyle changes among younger individuals, especially tackling consumption of industrialized foods and beverages, promoting physical activity and encouraging regular consumption of nutritious foods. Primary health care strategies addressing healthy lifestyles through family-based visits and surgical interventions showed reasonable cost-effectiveness.

Besides reducing costs in national health systems, incremental changes in diet associated with adjustments in physical activity level may prevent the onset of diverse NCD and reduce early mortality in different population groups worldwide, thus prolonging healthy life years and maintaining quality of life of individuals. In sum, following dietary guidelines will be a win-win situation for individuals and governments.

The Thought for Food was written by Flavia Mori Sarti, professor and researcher in Health Economics from the University of Sao Paulo, Brazil.

Glossary

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Dietary Guidelines for Americans 2020 – 2025 published

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The USDA has released their latest dietary guidelines document, with a new emphasis on the importance of considering different life stages when designing guidelines.

A new set of dietary guidelines are designed for the US population every five years, based on the recommendations of a scientific advisory committee who review the latest nutrition and health research, ensuring up-to-date advice.

In this document, specific dietary recommendations for infants and toddlers appear, where before this advice was absent. These recommendations cover breastfeeding and infant formula use, as well as complementary foods. Strong emphasis is placed on food variety for toddlers, as well as on the importance of iron and zinc intake.

The guidelines recommend that Americans should eat more whole fruits, vegetables, and whole grains, while limiting added sugars and saturated fat to less than 10% of daily calories each. While this largely chimes with the advisory committee’s scientific report, they had suggested that only 6% of daily calories be from added sugar, due to the negative health outcomes of high dietary sugar intake. The committee were also cautious on the contentious subject of saturated fat, not recommending any change to the current guidelines and mentioning that replacement of these fats with carbohydrates is not advised.

Nutrient density and dietary patterns were pulled out as important terms in the report. Nutrient dense foods are recommended throughout, and listed as vegetables, fruits, whole grains, seafood, eggs, beans, peas, lentils, unsalted nuts and seeds, fat-free and low-fat dairy products, and lean meats and poultry. However, the recommendations put emphasis on dietary patterns rather than on individual foods or food groups to enable adaptations that fit cultural, personal and individual needs and preferences. The three food patterns of the guidelines are the Healthy U.S-Style Pattern, the Healthy Vegetarian Pattern and the Healthy Mediterranean-Style Pattern. All three patterns provide most of their energy from plant-based sources, provide protein and fat from nutrient rich sources and limit intakes of added sugars, solid fats and sodium.

This is consistent with the results of the DELTA Model which illustrates that most of our energy should come from nutrient rich foods to ensure all nutrient requirements are met. Nutrient poor foods such as sugar should be minimised, and it is essential to consider the different needs of different demographic groups.

Interestingly, the guidelines make no mention of the environmental sustainability of different foods or diets. Several countries already make this inclusion, with this number likely to increase, but it will be at least 2025 before any such recommendations appear in the US dietary guidelines.

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WWF encourage planet-based diet

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The WWF report Bending the Curve: The Restorative Power of Planet-Based Diets joins other efforts to demonstrate the negative health and environmental consequences of our current way of producing and consuming food, while proposing ways to turn this around.

The report opens with the assertion that our food system must provide healthy, safe, affordable and nutritious diets for all, with reference to the UN Food Systems Summit later this year and the Sustainable Development Goals. This is completely in line with the principles of SNI: nutrition must come first when considering the global food system. The report then goes on to define planet-based diets as win-wins: healthy and with low environmental impacts and explores how these can be achieved.

A major recommendation of the report is that national dietary guidelines need to be more ambitious. This echoes a results of a previous WWF model. Currently, these guidelines largely reflect a healthier version of current consumption patterns and do not consider environmental impacts. The report argues that guidelines could be simultaneously healthier and more sustainable.

The main health recommendation of the report is to increase the plant-based proportion of the diet and decrease overconsumption. This is supported by the Global Burden of Disease study findings, indicating that low wholegrain and fruit intake, as well as high sodium intake, were the greatest dietary risk factors.

Beyond these overarching directions, recommendations for dietary and production change vary on a regional level. This is due to the difference in dietary, health and environmental factors seen in different parts of the world.

Countering biodiversity loss also requires a nuanced approach. For example, the report finds that most of the biodiversity loss associated with the Danish diet is due to imports of coffee, tea, cocoa and spices. Contrastingly, red meat holds this place for Latin American countries.

Similarly, the report states that we must feed our population on existing agricultural land and not further expand, but again the implications vary by region. Countries suffering from widespread undernutrition may need to expand their agricultural land to ensure healthy diets for their population, while more developed countries may need to contract.

The same regional variability is true for the planting of trees for carbon sequestration, conversion of grazing land to arable or optimising water use. The results of the report emphasise careful consideration of actions at a national level, as healthier diets can lead to increased environmental damage of one kind or another in vulnerable regions. A one-size-fits-all approach will not lead to a sustainable food system.

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GMO crops in the global food system

Genetically modified organisms (GMO) are already major contributors to the global food system since their commercial introduction in the 1990s. For example, over 90% of US corn and soy acreage is planted with GMO seeds. Despite this, the use of GMO is still controversial, with many individuals against their use and many authorities strictly regulating their production and consumption. Here, the arguments for and against GMO use in crop production are presented. 

GMO are defined as organisms, and products thereof, that are produced through techniques in which the genetic material has been altered in a way that does not occur naturally by mating and/or natural recombination. 

The process in which GMO are created differs depending on the degree of modification required but generally, a desirable trait is identified in one organism that could be of benefit in another. The trait is studied and, if possible, the gene(s) responsible for the trait are isolated. These genes are then introduced to the target organism, either via bacterial or viral infection, where the microorganism carries the target gene into the organism for uptake, or by bombarding the organism with particles coated in the target gene. 

The outcome of the process is a GMO that expresses the desired trait isolated from the original organism. 

Advantages of GMO  

The ability to transfer desirable traits between distantly related crops that cannot be interbred has obvious benefits. Examples of GMO use include the ability to increase photosynthetic rate, develop crops that are drought-tolerant with increased yields, and produce crops with disease resistance, such as blight-resistant potatoes

Moreover, crops can be developed that have greater nutritional value than conventional varieties. There exists a long list of such biofortified crops, including cassava with increased zinc, iron, protein and vitamin A content, high lysine maize, high provitamin A rice, and corn with increased provitamin A and folate. These crops are of particular value in global regions where nutrient deficiencies are a high priority public health issue. 

One widely used GMO is Bt-maize. This crop takes its name from Bacillus thuringiensis, the bacterium that donated to the maize plant the trait of producing an insecticidal toxin. Thus, Bt-maize is more resistant to pest insects than conventional maize, leading to higher yields and reduced pesticide use. As a result, 82% of the crop grown in the US in 2020 was the Bt variety. 

Disadvantages of GMO  

The arguments against GMO are largely based on health and environmental risks. The approval process for GMO is nationally administered, so differs between countries. Largely, these processes are more rigorous than for conventional foods and assess both the health and environmental risks of the GMO. 

The World Health Organisation states that no negative health consequences of approved GMO have been shown to date. However, concerns and risks do exist. One health concern raised is the possibility of allergenicity being unintentionally transferred between organisms. An example of this was when early GMO researchers, hoping to increase methionine content, found that the main allergen from Brazil nuts retained its allergenicity after transfer into a GMO soybean. As a result, the GMO soybean was never released commercially and allergenicity is now an important consideration when selecting donor crops. 

From an environmental perspective, there is the possibility that the GMO crop itself, or the introduced gene via cross-breeding or gene transfer, could escape the farmed environment and become a pest. The implications of this would depend entirely on the nature of the GMO crop; for example, transfer of a herbicide resistance gene to a non-target organism could lead to difficulties in controlling its growth. Alternatively, GMO crops could outcompete other plants due to the introduced trait, resulting in decreased biodiversity with unknown downstream implications. While the risk of these unintended consequences is low, they should be considered in the design and management of GMO. 

Finally, some express the opinion that GMO are morally wrong, as they involve too great an interference with living organisms. Such a decision can only be weighed by the individual but will likely mean that a proportion of the population will continue to avoid foods containing GMO products. 

This avoidance is challenging given the ubiquity of GMO products in many foods and by the difficulty for a consumer in identifying GMO foods. Different authorities take different stances on GMO labelling. For example, GMO are not specifically labelled in the US, rather foods that contain ‘bioengineered’ ingredients must be labelled as such. However, specific food labelling for certain types of GMO is on the horizon. The EU has stricter rules, with a requirement for GMO ingredients to be listed on food packaging. However, major food retailers have previously been forced to change their GMO policies due to the increasing “risk of finding GM material in non-GM food”. 

Conclusion 

GMO are widespread in the global food system, but not equally distributed.  

Moreover, regulation of GMO production varies and is not always clear and explicit. There are countries, like the US, where GMO crop production is widespread. Contrastingly, 19 member countries of the European Union have previously voted to either partially or fully ban the use of GMO. In New Zealand, no GMO crops are commercially grown. These variations in use and acceptance will certainly limit investment and development of future GMO. However, there is the opportunity for countries that have a GMO-free stance to use this status to market their products at a premium. 

GMO crops generally result in decreased pesticide use, coupled with increased yields and profitability. Moreover, there are those that believe that GMO will be necessary to adequately nourish a growing population and to adapt production to changing climates. The risks of GMO largely relate to unintended and uncertain consequences that must certainly be properly managed if GMO use and development is to increase. 

This Thought for Food was written by Cody Garton, a summer intern from Pūhoro STEM academy

Glossary

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Trends in undernourishment show promise

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A study of undernourishment in 76 countries found positive results, but not all global regions are progressing at the same rate.

Although overnutrition continues to grow globally, undernutrition rates are decreasing. Undernutrition currently affects more than 800 million people, either as protein-energy malnutrition or micronutrient deficiencies. 

The researchers used data from 1991-2013 from the FAO and the World Bank to analyse both undernutrition and related factors. The countries studied were mostly developing countries located in sub-Saharan Africa, Asia or Latin America. 

Undernourishment and child mortality showed decreasing trends overall. Urban populations, GDP, food production and agricultural land had all increased over the study period. However, when grouped into regions, the Eastern Mediterranean countries (Iran, Iraq, Jordan, Tunisia and Yemen) showed a late upwards trend in undernourishment, possibly due to political unrest in this region in the latter years of the study period. 

A problem noted by the authors is in equal distribution of food, both between countries and within national populations. This is a conclusion also reached by the DELTA Model, which shows that apart from a few micronutrients, the global food system in 2018 would have supplied sufficient nutrition for the world’s population, had it been equally distributed. The problems of unequal distribution are bound up in many other social, economic, political and environmental factors. 

While it is reassuring to see the decreases in undernourishment and infant mortality shown by this study, it also highlights areas that remain to be improved.

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Peas please

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Food Foundation in the UK are gaining traction with their ‘Peas Please: Making a pledge for more veg’ initiative, the results of which were recently described in Nutrition Bulletin. 

Despite a historically growing UK market for fruit, which has increased by around 50% since 1970, vegetable purchasing was seen to slowly decline over the same period. The common perceptions of vegetables as boring or not that tasty was likely not helped by minimal publicity, with only 1.2% of the UK food advertising spend used to market vegetables. On top of this, there are questions around the environmental impacts of the average UK shopping basket, and ample evidence that field-grown vegetables have small environmental footprints. 

Most of the UK public do not meet dietary guidelines for vegetables, particularly those with lower incomes. On top of low purchase rates, 40% of purchased vegetables in the UK are wasted at home. This matches the global trends of food waste shown by the DELTA Model, where most of the nutrient waste is from plant-sourced foods. Altogether, the nutritional and health implications of low vegetable intake due to consumer choice and waste needs to be tackled. 

The ‘Peas Please’ initiative aims to make eating vegetables more healthy, affordable, sustainable and pleasurable. Organisations, such as supermarkets and restaurants, pledge to follow these directives, in the hope of changing the way the country treats vegetables. Their website features ways in which individuals, communities and businesses can engage with the initiative and forge better relationships with vegetables. 

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Calcium comparisons between dairy, soy and almond beverages

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Research in the journal Current Developments in Nutrition has found that almond beverages were inferior to both milk and a calcium-fortified soy drink for bone health. 

The New Zealand researchers fed rats diets supplemented with either milk, or a soy-based or an almond-based drink. They analysed the amount of the liquid and feed consumed, as well as indicators of bone health and body composition. Fortified with calcium, the soy drink had the highest calcium (181 mg Ca/100 mL) and energy content (66 kcal/100 mL), while the almond drink had the lowest for both (105 mg Ca/100 mL; 29 kcal/100 mL). Milk lay in between for both energy and calcium (127 mg Ca/100 mL; 65 kcal/100 mL). 

The animals given the almond drink showed the least weight increase and the lowest body fat content. In terms of bone health, these animals showed the least bone growth, the lowest bone calcium content and the weakest bones. The fortified soy drink had results similar to those for milk, which is interesting given that the difference in calcium content between the almond drink and milk was far less than the difference between the fortified soy drink and milk. 

Many people, due to personal choice or health reasons, replace milk with plant-based beverages. The authors emphasised the need to consider more than just the energy or protein content of these replacements, which is particularly pertinent for elderly people prone to poor bone health. 

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Saturated facts

For nearly 50 years it has been believed that saturated fat is linked to heart disease. However, the scientific evidence does not universally support this assertion and recommendations are being made to change dietary guidelines and public knowledge around saturated fat. 

In response to increasing rates of heart disease in Western populations in the mid-20th century, the results of epidemiological studies comparing diets in different countries suggested that saturated fat intake could be a risk factor. Minimising the intake of saturated fat-containing foods such as red meat, dairy and chocolate was advised as a result. Currently, the NZ and UK dietary guidelines recommend reducing saturated fat intake, while the US and Australian Dietary Guidelines recommend the restriction of saturated fatty acids (SFAs) to less than 10% of total calorie intake in order to reduce the risk of cardiovascular disease (CVD). 

Saturated fatty acids (SFA), colloquially termed saturated fat, are molecules found in many common foods, especially animal fats and certain plant oils. Saturated refers to the molecular structure of the fatty acids, which have only single bonds between the carbon atoms, which cannot bond with any more hydrogen: thus, saturated with hydrogen. 

The claim that saturated fats were linked to negative health outcomes was accepted by public health institutes such as the World Health Organisation and the American Heart Association, and quickly caught on as a widespread belief. This has become so ingrained that, despite evidence to the contrary, it is proving difficult to change nutritional guidelines and the opinions of medical professionals, nutritionists, and consumers.  

A recent study, published in the Journal of the American College of Cardiology (JACC), performed a meta-analysis of randomized trials and observational studies on saturated fat. It was found that there were no beneficial effects of reducing SFA intake on cardiovascular disease and total mortality. While it was found that SFAs do increase cholesterol in most individuals, they increase concentrations of large particles of low-density lipoprotein (LDL) cholesterol, which is less correlated with CVD risk than the small, dense particles.  

An important finding of this study was that health effects could not be predicted from the SFA nutrient group alone; consideration of the overall macronutrient distribution and food matrix was necessary. Different SFAs have different physiological effects, which are further influenced by the foods they are found in and the carbohydrate content of the diet. Several foods relatively rich in SFAs but also rich in other nutrients, such as whole-fat dairy, dark chocolate, and unprocessed meat, were not associated with increased CVD or diabetes risk. 

There are calls to examine the overall risks of foods containing SFA, rather than SFA themselves. Likewise, the replacement of SFA-containing foods with those containing other fatty acids, often recommended in nutritional guidelines, was found unlikely to reduce CVD events or mortality. The authors of this last publication warned that current recommendations to replace SFA with alternative fatty acids may hinder efforts to get people to adopt more beneficial lifestyle changes, thinking that this single dietary change may be sufficient to reduce their CVD risk. 

One of the studies included in the JACC meta-analysis was the PURE (Prospective Urban Rural Epidemiological) study of 135,000 people from 18 countries on five continents. It found all types of fat (saturated, mono-unsaturated and polyunsaturated) were not associated with CVD, and saturated fat had an inverse association with stroke. Additionally, fat intake was associated with lower risk of total mortality. In contrast, a diet high in carbohydrates was associated with higher overall mortality risk.  

The claims around the negative consequences of fat intake may themselves have caused health problems. Reduction of saturated fat in the diet can lead to excessive consumption of carbohydrates as a replacement. Prevalence of obesity and type 2 diabetes has exploded in recent years, as seen in the chart below. Dr James Muecke, 2020 Australian of the Year, wrote in the Canberra Times“A flawed dietary guideline, which we have obediently and blindly followed for 40 years, is literally killing us. We’ve been encouraged to eat less fat and consume more carbs and yet we’ve never been fatter, our teeth never more rotten, and type 2 diabetes and its complications never more prevalent.” Dr Mueke makes clear the far greater need to prioritise reductions in excess carbohydrate consumption, rather than reductions in fat, to reduce the rate of non-communicable diseases in developed nations like Australia.

Rapidly increasing prevalence of obesity globally over the last 40 years. Source: World Health Organisation

In addition, advice to reduce consumption of nutrient-rich foods such as dairy and meat risks limiting the intake of nutrients such as calcium, iron, zinc, riboflavin and Vitamin B12. The Global Burden of Disease study shows that in the main, global health problems are caused more by what people do not eat – either through poor choice or through lack of choice – rather than an excess of certain foods. With the exception of excess sodium, the highest association of mortality and disability-adjusted life years globally was with insufficient intake of nutrient-rich foods. The study also showed the problems of consuming excess sugars. Consuming calorie-rich but nutrient-poor foods (e.g., sugary drinks) can displace nutrient-rich foods in the diet. The Global Burden of Disease study demonstrates that diets low in nutrient-rich foods are correlated with higher mortality. Importantly, saturated fat intake did not appear with any link to higher burden of disease. 

Number of deaths per 100 000 population attributable to individual dietary risks at the global level in 2017. Reproduced from the Global Burden of Disease study.

It is important for policy makers and health institutes to take all evidence into account when- designing nutritional guidelines. Arbitrary recommended intake levels for saturated fat will be less useful for the prevention of CVD or reduced mortality than targeting excess consumption, particularly of carbohydrates, and micronutrient deficiencies. Foods containing saturated fat, such as meat and dairy, can contribute to a nutritious balanced diet. They certainly should not be removed from the diet due to their saturated fat content, which has inconsistent links to modest impacts on CVD. Replacing these foods with carbohydrates will likely cause greater damage. 


Glossary

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