The Optimeal® tool for healthy, sustainable food products and diets

Both individual consumers and the food industry are increasingly considering the dual impact of their food on health and the environment. Quantifying how sustainable certain foods are is challenging, but the Optimeal® tool allows you to look at this question in detail.

Optimeal was developed in the Netherlands and has contributed to several scientific publications around the sustainability of diets. You can enter a daily diet into Optimeal, and ask it to optimise the diet for nutrition, or to minimise the environmental impact of the diet, or even to replace a certain food item with nutritionally equivalent foods. Optimeal then returns an altered diet that answers the question posed with the minimum degree of change to the original diet. This helps to ensure that the new diet would still be acceptable, due to its similarity to the original diet. 

Optimeal can also be used in food product development. For example, a food developer may wish to reduce the environmental impact of a new ready-meal, while ensuring that it meets some constraints around nutrition. Optimeal would optimise the increases and decreases needed to the ingredients in the meal that satisfy the developer’s requirements. 

Optimeal differs from the Sustainable Nutrition Initiative’s DELTA Model in the scale of sustainability it considers. Optimeal is excellent for analysing food and diets from an individual up to a national level, whereas the DELTA Model considers the sustainability of the global food system. Considering sustainability from the individual and the global perspective are both important in designing future food systems.


Glossary

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World Food Day

Our Actions are our Future: Grow, Nourish, Sustain. Together.

Today – Friday 16th October – is World Food Day, the 75th anniversary of the founding of the Food and Agriculture Organisation of the United Nations with its goal to achieve food security for all and make sure that people have regular access to enough high-quality food to lead active, healthy lives. We congratulate the FAO on reaching this anniversary and all the good work the organisation does.

At the same time, it is a day for all of us to reflect on the challenges facing the global food system. Despite advances in agricultural production methods and yields, we fail to produce and distribute sufficient food to nourish an increasing global population. Many production systems are damaging the natural resources on which they or other food production systems rely, and many food producers receive subsistence income from their products. The 2030 Sustainable Development Goal (SDG) of Zero Hunger looks as far away today as it did when the SDGs were first developed. 

Sobering facts from the FAO’s World Food Day 2020 webpage:

  • Over 2 billion people do not have regular access to safe, nutritious and sufficient food whilst the global population is still growing and expected to reach almost 10 billion by 2050. 
  • Nearly 690 million people are hungry, up 10 million since 2019. The COVID-19 pandemic could add between 83-132 million people to this number. 
  • The impact of malnutrition in all its forms – undernutrition, micronutrient deficiencies, as well as overweight and obesity – on the global economy is estimated at USD 3.5 trillion per year. 
  • Today, only nine plant species account for 66% of total crop production, despite the fact that there are at least 30,000 edible plants. We need to grow a greater variety of foods to better nourish people and sustain the planet. 
  • Approximately 14% of food produced for human consumption is lost each year between the “farm” and the wholesale market. Even more food is wasted at the retail food and consumer stages. 

Our ability to effectively nourish an increasing global population is one of the key challenges facing the human race. The global food system is incredibly complex, the world’s largest economic sector, with multiple inputs and outputs. It is often politicised, is subject to various socio-cultural forces, and touches every human being on the planet. Charting a course for the food system of the future requires quality thinking and discussion built on strong evidence-based foundations.   

The Sustainable Nutrition Initiative was founded to meaningfully contribute to this discussion.  Some key thoughts as we consider the future of food:   

The DELTA Model has been developed to help people explore different futures for the food system for themselves. 

The goal remains to achieve food security for all and make sure that people have regular access to enough high-quality food to lead active, healthy lives. We can all help towards this through understanding the food system in all its complexity, strengths, and weaknesses, leading to better informed discussion on the future of food for all of us. 


Glossary

Image from FAO World Food Day 2020 website

Protein: we need quality, not just quantity


Getting enough protein in our diets is essential for adequate nutrition. What is less well known is that protein represents a group of nutrients, the amino acids, each of which needs to be consumed in sufficient amounts. Here, we look at how we digest protein, the importance of amino acids, and show that protein quality, not just quantity, is vital.

Protein, alongside carbohydrates and fat, is one of the dietary macronutrients found on the nutrition label of all commercially-produced food. The recommended daily intake (RDI) for protein on these labels varies between authorities, but is usually around 50 g. This allows food companies to easily calculate and display on packaging what percentage of your protein RDI is supplied by their product.

But what is meant by ‘protein’ on these labels? And where do these RDIs come from?

Protein and amino acids

Proteins are a group of molecules essential to all life, distinguishable from carbohydrates and fats by containing nitrogen. The use of proteins in our bodies is broad: they form our tendons and ligaments as collagen, break down our food as digestive enzymes, and protect from infection as antibodies, among many other roles.

Every protein is composed of a string of smaller molecules, amino acids, folded into a functional shape. The amino acids in the string and the folded shape of the protein are specific to the function of that protein.

When we discuss protein as a dietary macronutrient, we are really referring to the supply of amino acids in the foods we eat, rather than the protein per se. The protein content seen on food packaging should really be seen as the sum of the amounts of each amino acid in the food.

Protein digestion and use

Protein is present in the majority of foods we eat. The amount and type of protein varies depending on the food, but all are subjected to the same digestive processes once eaten.

Protein digestion begins in the stomach. The body produces the enzyme pepsin, which starts the breakdown of proteins with the help of the stomach’s acidic conditions. Digestion continues in the small intestine, with the enzymes trypsin and chymotrypsin continuing the breakdown of proteins to individual or very short strings of amino acids (dipeptides and tripeptides).

These small molecules, rather than the original proteins, are absorbed by the intestine and transported around the body in the bloodstream. Once absorbed, amino acids are used to construct the many proteins needed by the body.

Consuming adequate protein in the diet is essential. Our bodies do not store protein in the way we can store fat or carbohydrates. Instead, there is a constant cycling of protein construction, breakdown and excretion. This protein turnover cycle leads to around 250 grams of new protein being produced each day, either using recycled amino acids from body protein breakdown, or from the amino acids derived from newly digested dietary protein. If dietary protein is lacking, this can lead to an overall depletion of body protein over time.

The importance of each amino acid

The most common way of calculating protein RDI is by bodyweight. For example, a frequently heard recommendation is that you should eat 0.8 g of protein each day for each kg of bodyweight. Thus, a 75 kg man should consume 0.8 x 75 = 60 g of protein each day. However, there is a lack of consensus around the value of 0.8 g, with many arguing that intake should be at least 1 g, particularly for athletes and older adults.

This calculation around protein RDI hides the more specific amino acid requirements of the body. There are 20 common amino acids, 9 of which are essential. Essential means that the body cannot effectively make these amino acids itself, so must obtain them from the diet.

There are RDIs for each essential amino acid, based on the amount required for body protein production. However, these RDIs are not displayed on food products, as this would be difficult to calculate for each food and make understanding nutrition labels more difficult. Instead, the protein RDI approximates what is needed based on the amino acid content of an average diet. This approximation was designed for a population that consumes a diverse diet over time. It is less fitting for day-to-day protein consumption of the individual, particularly those who consume only a limited range of protein sources. As an individual, it’s important you obtain enough of each essential amino acid each day.

What happens if we don’t get enough of a certain amino acid?

The result of deficiency in amino acids is best explained through an analogy.

Imagine you are assembling toy cars. The process involves painting the body of the car green, and then putting on the wheels. You have a box of car bodies, a pot of green paint, and a box of wheels.

As you are assembling these cars, you come to a point where you still have car bodies and wheels, but you have run out of green paint. However, with a little more effort, you can make more green paint by mixing some blue and yellow paint you have. With this newly made green paint, the assembly process can continue.

However, if you come to a point where you have car bodies and paint, but have run out of wheels, you cannot continue to assemble the cars. No matter how much of the other two components you have, the wheels are essential, so car assembly must stop until you have more wheels.

The construction of the toy cars from components is analogous to the construction of a protein in the body from individual amino acids. In the assembly of a protein, several different amino acids are required. Like the green paint, if the body runs out of a non-essential amino acid, then it can produce more from other amino acids, although less efficiently. However, if the body runs out of an essential amino acid (those that must be derived from the diet), protein synthesis is halted – much like running out of wheels in the toy car assembly.

If you do not obtain sufficient essential amino acids from your diet, synthesis of necessary proteins can be halted. The wheels in the toy car analogy are the ‘first limiting’ component in car assembly. In humans, it is often the amino acid lysine that is the first limiting amino acid to protein synthesis. This is because lysine is required in a large number of proteins and is not always readily available from the diet. A person can be protein deficient by being deficient in just one essential amino acid, regardless of the amount of the other amino acids they consume. And since the body is unable to store protein, an excess of unused amino acids consumed will be wasted by the body when it cannot immediately use them. Getting enough of each essential amino acid is required for optimal health.

How do I ensure I get enough of each amino acid?

Different foods contain different distributions of amino acids. For example, chickpeas are higher in lysine than oats, but the reverse is true for the amino acid cysteine. Plant foods are more often limited in certain essential amino acids than animal foods, due to the similar proteins required by animals and our own bodies. If plant-sourced foods are your main source of protein, it is important to understand their amino acid profile. Plant foods with complementary amino acid profiles can be consumed together to make up for their individual deficiencies.

Another important consideration is amino acid bioavailability; the percentage of the total amino acid that is available to the body from different food protein sources. The efficiency of the protein digestion process varies depending on the structure of the protein consumed and the food matrix proteins are contained in. Extensive research has been performed on the bioavailability of each amino acid in human foods. The table below gives a summary of bioavailability values for some selected foods.

FoodAmino acid bioavailability
(% of total consumption that is absorbed)
Roasted beef94 – 99  
Fish81 – 94
Cooked kidney beans64 – 100
Oats70 – 88
Potatoes47 – 66
Rice75 – 99
Skim milk78 – 97
Cooked soyabeans71 – 90

Bioavailability of amino acids can vary widely between foods. Therefore, it is useful to have a score for each food reflective of the overall amino acid availability, commonly referred to as protein quality. The DIAAS score (Digestible Indispensable Amino Acid Score) is recommended by the UN Food and Agriculture Organisation for this purpose. The digestibility of each essential amino acid in a food is calculated and compared to a reference protein, and the DIAAS is the lowest of these calculated values. The score is thus reflective of the digestibility of the most limiting essential amino acids in the food.

A DIAAS score of 100 or more indicates excellent protein quality, with high digestibility of all the essential amino acids. Scores between 75 and 100 are considered good sources of protein, but consuming complementary proteins would improve their profile. Scores below 75 are of lower quality. Some example foods with their DIAAS are given below.

FoodDIAASLimiting amino acid(s)
Beef (roasted)99Leucine and Valine
Pea protein concentrate82Methionine and Cysteine
Rice (cooked)60Lysine
Skim milk powder105Methionine and Cysteine
Soya protein isolate84Methionine and Cysteine
Wheat45Lysine

Generally, animal-sourced foods have higher DIAAS scores than plant-sourced foods. This means that the profile of amino acids is better suited to human digestion and to fulfilling our needs for protein synthesis.

At a global scale, producing enough of each amino acid is critical to the ability of the food system to meet nutrient needs. When considering possible future scenarios, the DELTA Model predicts the supply and bioavailability of essential amino acids, as well as total protein.

Take home message

The single macronutrient protein consists of a group of essential nutrients: the amino acids. These molecules are what is needed in our diet to construct the diverse body proteins, essential to bodily function, health and life.

Getting enough protein in your diet is not just about reaching the protein RDI. Instead, you need to reach the RDI for each essential amino acid. This is most easily achieved by eating high-quality protein, or combinations of protein sources with complementary amino acid contents.


Glossary

References for DIAAS values: 1, 2, 3, 4

Green car photo by MW on Pixabay. All other photos courtesy of the Riddet Institute.

Higher atmospheric CO2 changes the nutritional quality of vegetables

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Vegetables grown at higher carbon dioxide (CO2) concentrations may grow better but may not have the same nutritional benefits. 

Increasing atmospheric CO2 concentrations have prompted research into the effect of this phenomenon on plant growth. In general, elevated COis good for plant growth, increasing yield and environmental stress tolerance. However, a review of the research in this field has found that elevated CO2 also reduces the magnesium, iron and zinc content of vegetables. This reduction was as much as 31% for iron in leafy greens. 

In specific vegetables, the review found that sugar content of lettuce, tomatoes and potatoes increased at higher atmospheric CO2 concentrations, while protein content decreased. Other factors, such as antioxidant content, were strongly affected, but this effect was different between different vegetable cultivars. 

Higher yields with lower protein content have also been found for staple crops and grains grown at elevated CO2 concentrations. These changes occurred alongside reduced iron and zinc content. 

In a future with increased atmospheric CO2 concentrations, our crops and vegetables may grow larger and sweeter, but the amounts of other essential nutrients that we get from them may decrease. This could lead to higher caloric intakes required to obtain the same amount of nutrients from these foods. While the concentrations reviewed in this publication were high compared to those expected in the near future, we should be prepared for some degree of impact on our crops. Targeting crop varieties which make the best of the changing conditions is being explored.

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Glossary

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Canteen food waste can be more than food consumed

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A case study of a US school canteen found that 54% of all food purchased was uneaten.

Globally, the UN estimates that around one third of food is wasted somewhere along the path from on-farm production through to in the home. This represents a huge challenge to creating a sustainable food system, and waste reduction is a key target for improving sustainability. However, a recent case study shows that certain eating environments including different age groups may contribute more to food waste than others. 

The researchers followed the path of food in a US school canteen from purchase, through service and consumption to what was left on the plate after lunchtime. This plate waste accounted for 37% of the total food purchased, with preparation losses taking the total wasted up to 54%. This plate waste value was much higher than the 2-39% found in US households, suggesting differing behaviour in the canteen environment. 

The difference may also be because the canteen users were predominantly children. Food waste decreased with age in this study: elementary and middle school children wasted around half of the food on their plates, whereas high school children and staff members wasted around 30%. Perhaps unsurprisingly, fruit and vegetables were the most wasted food groups. 

The researchers conclude that service changes (such as reducing the number of buffet choices) would be the easiest changes to implement, but not the most effective. The most effective strategies would target the food choices made by the canteen users and understanding why waste is greater at school than at home. 

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Glossary

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Microbiomes and Sustainable Nutrition


Did you know that around 10% of your daily energy intake is supplied by intestinal microbes? Or that many plants and animals that we rely on for food are dependent on microbes for their survival? Although the connections between the microscopic world and the global scale of sustainable nutrition are not obvious, microbes play a significant role in the way our food is produced, processed and digested.

The term microbiome refers to a collection of microbes in a certain location. For example, the human gut microbiome consists of the microbial population living in our intestinal tract, which is receiving increasing attention as we recognise its importance in human health.

Microbiomes exist in diverse locations, many of which form part of the global food system. The role of these microbiomes in delivering sustainable nutrition for the global population is increasingly clear.

Cereal crops are a staple food source for the global population, providing predominantly energy and protein. These crops rely on soil nutrients, such as nitrogen, to grow and produce the protein we then consume. Often these nutrients are applied to cropland as fertiliser, produced either industrially or from animal sources. Management of fertiliser application is essential to avoid environmental damage caused by excess nutrients in soils and waterways.

Nitrogen can also be captured directly from the air by soil and root microbiomes, and microbes associated with roots can increase the availability of micronutrients to the plant. These microbes also increase the resistance of crops to soil pathogens. Moreover, soil microbes play a role in reducing soil erosion by producing products that bind the soil together. Current soil microbiome research is tackling the problem of reduced crop yields due to microbiome depletion and working to understand how the beneficial impacts of soil microbes can be harnessed. Learn more

In addition to plant-sourced food products, microbiomes are essential in the production of animal-sourced foods. An example of this is the rumen microbiome. Much of the forage consumed by ruminants cannot be digested by the animal’s own digestive enzymes; instead, the action of rumen microbes converts resistant plant matter, such as cellulose, to nutrients that can be absorbed by the animal’s digestive tract. These microbial products form the majority of energy intake for many domesticated ruminants. The action of the rumen microbiome is thus an important step in converting inedible plant material into animal-sourced food products in our own diet.

Rumen microbiome research currently has a strong focus on minimising the production of methane, a greenhouse gas and by-product of digesting plant material, by the rumen microbiome. This research is unpacking what causes certain microbiomes to produce less methane than others, and what the impact of different animal feeds is on methane production. Learn more

Continuing along the food supply chain, microbes are responsible for the production of common fermented foods. Fermented foods include cheeses, yoghurts, kimchi, sourdough and fermented meats, and are produced via the introduction of microbial populations to the raw food material. Apart from changing the taste, texture and appearance of these foods, the fermentation process enables perishable foods to be stored for longer periods, which can reduce food waste. The nutritional value of fermented foods is also enhanced in many cases. For example, the fermentation of cabbage to sauerkraut results in vitamin B12 synthesis, a nutrient not available in unfermented cabbage. There is also the probiotic capacity of fermented foods: their consumption can introduce beneficial bacteria to the human gut microbiome. Learn more

Microbiomes continue to play a role in the food system even after food is eaten. Although there are microbiomes in different sections of the human digestive system, the gut microbiome is intensively studied for its impacts on human nutrition and health. The make-up of our microbiome is in part determined by our diet, which forms the major food source for intestinal microbes. Just as our own ten trillion human cells require the nutrients we eat to carry out their function, so too do our equally numerous microbial cells. Current research is demonstrating increasing links between gut microbiome composition and various outcomes for human nutrition and health. This includes links to energy and nutrient yield from the diet, roles in intestinal disease and even impacts on brain function and mood. It is now recognised that we cannot have a full appreciation of human nutritional health without consideration of the gut microbiome. Learn more

A sustainable food system is one that ensures food security and nutrition for all, without compromising the future of the economic, social and environmental bases that the system depends on. Microbiomes are a critical element of a sustainable food system. Soil microbiomes enable and enhance crop growth, while playing a protective role in minimising the environmental damage of farming. Animal microbiomes are essential for the conversion of inedible plant material to animal-sourced foods, essential for food security in many developing parts of the world. Fermented foods are an integral constituent of the diet in many cultures and provide a means of preserving perishable foods, as well as adding nutritional and financial value. Finally, the human microbiome in part determines the nutrition we obtain from the foods we eat.

Microbiomes are present throughout the food system, and touch on all aspects of sustainability. As such, designing sustainable food systems for the future must involve consideration of the microbial element.


Glossary

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The cheapest nutritionally adequate diet contains both plant- and animal-sourced foods

A recent paper published in Nature Food asked what foods would be in the cheapest diet that satisfies nutritional requirements. Combining the prices and food composition data for common food items in the US, the authors determined the cheapest way to feed one person a nutritionally adequate daily diet.

The cost of the diet was calculated as US$1.98 per day (NZ$3.02). It consisted of 15 foods, all of which could be found in the average US home kitchen. The top five contributors were milk, legumes, rice, potatoes and corn tortillas.

The authors also analysed what level of price increase to animal-sourced foods was necessary before the cheapest diet became entirely plant-based. Between 200-1,150% increases in the cost of animal-sourced foods was required, and the plant only diet would cost US$3.61 per day (NZ$5.51). The plant only diet overlapped with the original diet for many foods, but also included soy beverages, green peas and peanut butter.

The authors highlighted that the bioavailability of consumed nutrients was not considered in this study. Inclusion of bioavailability would likely increase the cost of both diets but would have a greater impact on the plant-based diet, due to the lower bioavailability of many nutrients in plant foods. The daily diets proposed by the authors are not recommended diets – a limit of 15 different foods is not feasible – but the work does show that animal-sourced foods can be a cost-effective way to get adequate nutrition.

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Glossary

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Impact of COVID-19 lockdowns on sustainable nutrition

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Many countries across the world instituted a degree of lockdown this year to minimise the harm caused by the COVID-19 pandemic – but what effect does a lockdown have on nutrition and sustainable food production?

The impact of the Spanish lockdown during March and April 2020 on nutrition has recently been investigated by researchers from multiple Spanish and international universities. They found that the amount of food purchased increased slightly during the lockdown (from 13.8 to 14.3 kg per person per week). Plant foods were the major part of the increase, followed by eggs and red meat. Beer and coffee purchasing decreased, possibly due to the closing of restaurants and bars.

Food energy intake increased by 6% during the lockdown compared to the same period in previous years, while the nutritional quality of the lockdown diet was 5% lower. The environmental footprint of the lockdown diet was also greater than pre-lockdown: increases were found for water use, land use and global warming potential.

While this study only considered the impact of the Spanish lockdown, the trends are likely to be true for lockdowns in many countries. The results of this research highlight that changes to the global food system must take into consideration the potential for unexpected events to disrupt progress towards sustainable nutrition.

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Glossary

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Emissions on farm vs off farm

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The Environmental Working Group breaks down the life cycle analysis of total greenhouse gas emissions for common protein foods and vegetables.

As expected, animal foods have significantly higher greenhouse gas emissions. Lamb, for example, has the highest because it generates methane through enteric fermentation and produces less edible meat relative to the sheep’s live weight. Most emissions from meat, dairy and fish occur during production. However, most emissions from plants are generated after crops leave the farm. This is primarily because of the energy needed to cook plant-based foods. For example, post-farmgate emissions account for 65% of dry beans’ total emissions and 59% of lentils’ total emissions.

This does not mean plant-based foods have greater net post-farmgate emissions. For example, 65% of dry bean’s emissions is post-farmgate, which equates to 1.3kgCO2e. On the other hand, while only 10% of beef’s emissions is post-farmgate, this is a larger total of 2.7kgCO2e. The key message is that the main sources of emissions vary among different foods, depending on production and food preparation methodology. This means it is inappropriate to only compare footprints at the production stage. A more holistic view of environmental impact is required for a fair comparison.

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Glossary

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Build a food system from nutrient rich foods first


The philosophy of the Sustainable Nutrition Initiative (SNI) is to help create a better understanding of our food systems and identify opportunities for improvement. This is to ensure that in the future we can sustainably feed the global population. SNI has developed a modelling approach to test any range of possible scenarios that could contribute to globally sustainable food systems; The DELTA Model. This Model is unique because it explores the ability of different food production scenarios to provide the bioavailable nutrients needed to adequately feed the global population. The Model does not try to identify or prescribe options for diets for individuals, as there are many ways individuals, particularly those with money and access to different food types, can meet their nutrient requirements. Rather, it enables the creation of scenarios to inform discussions about possible future food production systems that meet the nutrient requirements of the entire population.

A critical feature of a sustainable food system is that the food produced is sufficient to provide the bioavailable nutrients required by the global population. However, there are imbalances in the production and consumption of these nutrients, causing a range of health issues. There is also sub-optimal use of resources, including environmental resources, to produce and distribute food. Globally, the current food system provides sufficient energy and macro-nutrients, but not sufficient micro-nutrients and trace elements, to meet global requirements. Therefore, production and consumption of nutrient-rich foods, particularly those that address micro-nutrient and trace element deficiencies, should be a priority.

There is an increasing challenge to feed the world within global resource constraints

The target of the global food system is to meet nutrient requirements of the global population. This includes all nutrients that humans must obtain from their diet to survive and thrive; energy, macro-nutrients – including essential amino acids as part of overall protein, micro-nutrients and trace elements. However, the earth has limited resources. There is a limit to the amount of food that can be produced before we run out of land, water and other resources. Not all food production scenarios are practical within these constraints. It is therefore a challenge to use resources optimally to ensure all nutrient requirements are met.

The global food production system produces enough energy to feed the world, but problems arise from lack of choice or poor choice

The current food system already has sufficient, even an abundance of energy and macro-nutrients to feed the global population. According to FAO, the world produces around 2,900 calories, 83 grams of protein, and 84 grams of fat per person, per day. This is more than enough to meet the average human requirements. There are however imbalances in the production and consumption of such nutrients. The reason that 11% of the world is undernourished is because of the inequality in access to food (distribution and affordability), rather than production scarcity. Other health issues caused by an under or over consumption of energy arise from a lack of choice or poor choice.

There is not enough production of some micro-nutrients to feed the world

While there is evidence that global food production can feed the world on a calorific basis, the micro-nutrient and trace element requirements of the global population may not be able to be met, even with perfect distribution and zero waste.

According to WHO, an estimated 2 billion people have a micro-nutrient or trace element deficiency (including clinical and sub-clinical deficiencies). Micro-nutrient and trace element deficiencies are common contributors to poor growth, intellectual impairments, and increased risk of morbidity and mortality. This is often referred to as ‘hidden hunger’; it doesn’t always cause death in the way protein-calorie hunger does. Instead it often results in individuals ‘surviving but not thriving’. Long-term consequences occur not only at the individual level but have detrimental impacts on national economic development and human capital. The most common deficiency is iron which affects a quarter of the global population. In some cases, these deficiencies are due to poor dietary choice, but others are due to a lack of choice resulting from limited access.

The DELTA Model shows that if all food that is currently produced was distributed evenly globally, there would still be shortages against requirements for some micro-nutrients and trace elements such as calcium, iron and zinc. In other words, the global food production system currently cannot provide sufficient micro-nutrients and trace elements to feed the world. This indicates resources are not being used to produce food that is optimal for meeting human requirements.

The food system should prioritise nutrient-rich foods

To ensure that the food we produce has sufficient nutrition to feed the global population, while still staying within the constraints of planet earth, nutrient-rich foods should be prioritised. The food system should be built from foods that deliver highly bioavailable quantities of micro-nutrients. This is particularly important for the nutrients in short supply (like calcium, iron and zinc), but as part of an overall nutrient-rich profile.

For example, the richest and best-absorbed source of calcium is cow’s milk and its derivatives. Other foods show high concentrations of calcium; however, bioavailability is variable. Milk is an efficient source of calcium in the food system. But the real benefit lies in dairy being a balanced source, rich in multiple nutrients other than calcium, including high-quality protein, zinc, vitamin B12 and riboflavin.  

For iron, the best sources come from animal-sourced foods, including red meat. This is because the bioavailability of haem iron from animals is much greater than non-haem iron from plant sources. Haem iron also helps the absorption of non-haem iron. Therefore, it is important to have sufficient red meat, alongside plant-sourced foods in the system to meet global iron requirements.

Of course, animal-sourced foods are not the richest source of every micro-nutrient and trace element. For example, vitamin C is best sourced from plants. The key is that starting with foods rich in bioavailable nutrients helps to ensure the global nutrient requirements are met, while using the limited production resources in the most efficient way.

If the food system is built up from the most nutrient rich foods first, energy as well as other macro-nutrients will naturally be met, as these are inherent in food groups. For example, milk also contains fat and protein, as well as the micro-nutrients and trace elements as explained above. Therefore, improvement and optimisation of food systems should place priority on nutrient rich foods.


Glossary

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