V.I.M. (Very Important Microbioma)

Recently, knowledge about the importance of human interaction with microorganisms is questioning the lifestyle of many societies while recognizing the importance of biodiversity in every way.

We had the pleasure of talking to Dr. Clelia Peano, a researcher of the Institute of Genetic and Biomedical Research CNR and Head of Genomic Unit at Humanitas Clinical Center in Milan, Italy. Clelia is part of a group of researchers studying the intestinal microbiome with an aim to understand the functions of microorganisms and their impacts on human health.

Dr. Clelia Peano explaining us the importance of intestinal microorganisms and their effects on human health.

It is worth mentioning that the importance of the microbiome is recently recognized by the scientific community. Only since the year 2000, the interactions of microorganisms with their host (animals (humans), plants, soil, water) are known to be relevant to the sustainability, balance and overall health of all constituents within the ecosystem.

But now, let’s allow Clelia to explain it to us:

What is the microbiome?

The microbiome is composed of all microorganisms (e.g. bacteria, fungi, etc.) that colonize an environment. It constitutes an ecosystem.

What is the human microbiome and why is it important?

The human microbiome refers to all microorganisms (e.g. bacteria, fungi) that live within our body.

Inside the human body, the skin and the intestine are the organs that are colonized by the largest diversity of bacterial species (more than one thousand species), followed by the oral and pharyngeal tract (more than six hundred spices). 

The microbiome is important because our body is dominated by bacteria. As a matter of fact, the bacterial cells colonizing our body are 10 times more abundant than are our human cells.

Inside the intestine, microorganisms exert very important functions such as extracting energy from food, producing vitamins and regulating the immune system, glucose level and metabolism.

How does the microbiome control these body functions?

The microbiome produces metabolites that can contribute to maintain a  systemic state of equilibrium or, in some cases, can cause diseases.

The alteration of the correct balance between the microbiome and the immune system is known as dysbiosis, and it can be correlated with the occurrence of diseases such as asthma, diabetes, obesity, liver disease, depression, heart disease, colon cancer and inflammatory bowel disease.

What is the difference between a healthy microbiota and a sick microbiome?

An important difference is related to the relative abundance between different kinds of bacteria. For example, a sick or dysbiotic microbiome has a higher ratio between femicutes/bacteroidetes, and can lead to a systemic inflammation, while a healthy microbiome exhibits a higher bacteroidetes/fermicutes ratio that may be correlated with the maintenance of low levels of inflammation.

What factors influence the microbiome composition?

First of all, the microbiome is an ecosystem that responds and continuously adapts to the organism that hosts it; in this case to our body and lifestyle.

The factors that influence the microbiome composition are:

  • food: a diet poor in fiber, high amounts of processed foods and high levels of sugars, predisposes to gut microbiome dysbiosis;
  • lifestyle: poor physical activity and excessive/use of drugs can compromise the balance of our microbiome. For example, excessive use of opioids can slow down the digestive process, antipsychotics can have a direct antibacterial effect, gastroprotectors can cause gastric cancer;
  • genetic predisposition: our genes play an important role in shaping our intestinal microbiome, this was demonstrated in a study in which from the analysis of 416 pairs of twins, it was observed that identical twins (homozygotes) have a microbiome more similar to each other than different twins (heterozygous).
Dorila Peranchiguay feeds her chickens outside her house in the island of Teuquelín, a part of the Chiloe islands off the coast of Chile. The only inhabitants of Teuquelín are the Peranchiguay family, whose descendants arrived there two hundred years ago. The men and youth have mostly left in search of work. Those left behind (mostly elders, women and a few children) make a living by harvesting Luga, an algae that is used in the production of shampoo and diapers. Foto by Karla Gachet.

Two stories to better understand how the intestinal microbiome evolves and transforms, adapting itself over the course of human lives:

1. Comparison between the intestinal microbiome of Hazda and Italians:

We compared the microbiome of two very different populations: the Hazda, and the Italians.

  • The Hadza are a nomadic population living in Africa (Tanzania). They are the last Human hunters and gatherers living on Earth. They have a lifestyle similar to that of the people who lived in the Paleolithic era which occurred more than 10,000 years ago. They have never experienced either agriculture or farming.
  • Italians, on the other hand, are a settle/civilized population living in Europe. They have a western lifestyle and live in urbanized environments.
  • The Hadza microbiome is dominated by bacteria that serve to degrade fibers while the microbiome of Italians is specialized in the degradation of carbohydrates. Since the diets of these two peoples have a very different composition, the diet of the Hadza is much more diversified and involves the consumption of large quantities of fiber and protein, while the diet of Italians is made up of more than 50% of carbohydrates.
  • In the Hadza microbiome, there are no Bifidobacteria, which are present in the microbiome of all other human beings. Their microbiome is different from that of all other peoples: Africans, Europeans and Americans.
  • The Italian Microbiome is rich in bacteria that perform functions to metabolize drugs, antibiotics and pollutants. These functions are totally absent in the Hadza microbiome.
  • Genes for antibiotic resistance in the Hadza intestine are derived from soil bacteria, which are antibiotic producers, and give an advantage to them.
  • Genes for antibiotic resistance in the intestines of Italians derive from the excessive use of these drugs and are a disadvantage for us.

2.Comparison between the intestinal microbiome of newborns and centenarians:

To understand how the microbiome develops and transforms itself over the course of our life, we compared the microbiome of individuals of very different ages: newborns and centenarians.

  • The microbiome of infants is dominated by Bifidobacteria, which are essential for the digestion of oligosaccharides (sugars polymers) contained in breast milk and for the correct development of the immune system.
  • The interruption of breastfeeding allows the complete maturation of the intestinal microbiome of the newborn.
  • The species and bacterial strains found in the microbiome of newborns derive from the mother’s microbiome. The mother is the main source.
  • The microbiome is essential for the correct development of the immune system in newborns.
  • The intestinal microbiome of centenarians and ultra-centenarians is different from the microbiome that colonizes human bodies during the rest of life.
  • In Centenarians and ultra-centenarians, the microbiome is essential for maintaining the state of health and balance within the immune system. Their microbiome is characterized by the presence of the bacterial genus Christensenellaceae.

What are the advantages of the clinical study of the intestinal microbiome?

The study of the intestinal microbiome can be fundamental for prevention, early diagnosis and therapy and can help to successfully integrate drug therapies while utilizing a personalized diet.

What awaits us in the future?

Once reliable markers associated with the intestinal microbiome dysbiosis in relation to the onset of pathologies is established and validated, it will be possible to integrate microbiome analysis (from fecal samples) with other non-invasive analysis (urine, blood and saliva samples) to combine different clinical parameters and thus obtain a complete diagnosis that can allow us to identify personalized therapies that include the correct and personalized prescription of drugs and diet.

In addition, information about genes and metabolites can help doctors to provide a more effective, comprehensive and personalized health care plan for each individual in the future.

Conclusions:

Our lifestyle (nutrition, exercise, drug intake) affects our health. The quality of the food we eat, the quantity and the diversity in our diet influences the balance of our microbiome and, consequently, our health.

Biodiversity and integration: Biodiversity is always positive both in the environment and within our gut. Let’s respect and improve biodiversity by all means!

Another important point to consider is that the excessive use of antibiotics (in humans, animals and plants) not only affects the microbiome but also causes resistance. Antibiotic resistance is a major problem today! To get an idea, watch this video that illustrates the problem and, for more information, check out the World Health Organization webpage dedicated to this topic. We will develop more on this topic in future posts. Stay tuned!

Publications to which Clelia has made reference:

Nature Communications, 2013. Schnorr, SL. et al. Gut microbiome of the Hadza hunter-gatherers.

Current Biology, 2015. Rampelli, S. et al. Metagenome Sequencing of the Hadza Hunter-Gatherer Gut Microbiota.

Cell, 2014. Goodrich, J.K., et al. Human Genetics Shape the Gut Microbiome.

Health, Food and Biodiversity: INSEPARABLE

As Hippocrates, the father of medicine, already stated ca. 460 BC, …”Let food be thy medicine and thy medicine your food”…  our health is directly related to the food we consume!

This raises up the question, what shall we eat to be healthy?

The WHO (World Health Organization of the United Nations) emphasizes the importance of eating fruits, vegetables and legumes, and to restrict consumption of free sugars, trans-fats and salt.1

Importantly, it points out that diets evolve over time, being influenced by social and economic aspects including cultural traditions, individual beliefs and preferences, food prices and environmental factors.1 Therefore, an ideal diet can only be established inside the local contexts, meaning that there is a huge diversity of diets.

Every May, in some towns in the state of Guerrero, Mexico, the Feast of the Holy Cross is celebrated. Each day of the party, the men of the family dispossess animals and the women prepare large quantities of food for all the people invited to the celebration. The smells of mole, tamales, pozole, corn and mezcal travel across the streets. Photo by Karla Gachet.

In recent years, the awareness regarding a sustainable way of eating has increased.

For FAO (Food and Agriculture Organization of the United Nations) …”sustainable diets are diets with low environmental impact which contribute to food and nutrition security and to healthy life for present and future generations. Sustainable diets are protective and respectful of biodiversity and ecosystems, culturally acceptable, accessible, economically fair and affordable; nutritionally adequate, safe and healthy; while optimizing natural and human resources.”…2

So, sustainable diets are healthy diets for which the economic, social and environmental aspects are taken in consideration, right?

A nice way of looking at the relationship between the nutritional value of food and its environmental impact is the double food and environmental pyramid model developed by the Barilla Center of Food and Nutrition and adapted to the Italian Mediterranean diet. For example, animal products that have a high environmental impact (bottom of the environmental pyramid) are recommended to be consumed in low amounts (top of the food pyramid) and fruits and vegetables that have a low environmental impact (top of the environmental pyramid) are recommended to be consume in high amounts (bottom of the food pyramid).

Of course, all of this has to considered within the local context. If you live in north Canada as Inuit do, you might not be able to eat lots of fresh fruits and vegetables and you probably get high quantities of animal products, and that is ok! In fact, for centuries, we all have adapted to our local conditions by eating mostly local food.

The Baihua and Tega families meet up in the river after the Tega family had hunted a monkey, a wild pig and a deer. The Huaorani community of Bameno is on the Cononaco River in the Yasuni National Park in the Amazon rainforest of Ecuador. Hunting is still the main way to obtain their food. Photo by Karla Gachet.

And very importantly, we shall not all eat the same to be healthy. For example, indigenous people inside the amazon don’t need wheat as a source of carbohydrates as they have manioc, they don’t need olive oil as they have other sources of healthy fats (e.g. sacha ichi, Brazilian nut, macambo), they don’t need salmon as they have paiche. Wouldn’t you agree?

And we are not saying we should eat strictly local food but, if we prefer it on regular basis, we support the local economy, preserve local traditions and protect local environments. 

A very interesting article presented in the National Geographic magazine shows the evolution of diets and how similar or diverse these are in different countries. Really worth seeing.      

According to FAO, diets that are healthy and sustainable have the following characteristics:2

  • diverse (a wide variety of food)
  • balance between energy intake and energy needs (or eat what the body needs)
  • based on minimally processesed tubers and whole grains; legumes; fruits and vegetables – particularly those “robust” (or less prone to spoilage) and those which require less of rapid and more energy-intensive transport. Meat, if eaten, in moderate quantities – and all animal parts consumed
  • eat in moderation: dairy products or alternatives (e.g. fortified milk substitutes and other food rich in calcium and micronutrients)
  • unsalted seeds and nuts
  • small quantities of fishand aquatic products sourced from certified fisheries
  • very limited consumption of food high in fat, sugar or salt and low in micronutrients (e.g. crisps, confectionery, sugary drinks)
  • oils and fats with a beneficial omega 3-6 ratio such as rapeseed, olive oil, avocado oil (and others)
  • tap water in preference to other beverages.  

In fact, these characteristics can be adapted to all diets, don’t you think?

Homemade bread and cheese accompanied with a salad of green leaves and broad beans. The bread was made with the leftover whey from the cheese preparation.

But let’s wait a second, before industrialization and globalization, weren’t these characteristics followed by most cultures? It might be wise to look back and retake some food habits practiced by older generations.

A practical example of a healthy and sustainable dish has recently been presented in the study of the EAT-Lancet Commission.3 Worth seeing!

Why is diversity so important?

The diversity of diets is not only key for protecting the loss of biodiversity (i.e. genetic, species and ecosystem diversity4) and environment degradation but to preserve human food cultural knowledge as well.

Keep in mind that diversified varieties, cultivars, and breeds of the same food have different nutritional content.4

Since the beginning of agriculture (ca. 12000 years ago), we have faced a dramatic loss of plant and animal species used by humans as food. For example in Thailand, from the 16,000 varieties of rice traditionally cultured, today, only 37 are being cultivated.4  

Not all of us should be eating the same things. Local traditions need to be preserved for our health and for the health of our planet!

The Huaorani community of Noneno is located along the Shiripuno River in the Amazon rainforest of Ecuador.  Many of the communities have moved away from hunting and adopted more modern ways of eating such as rice with canned tuna and pasta. Photo by Karla Gachet.

Recently, a scientific study has quantified the mass of life on earth (biomass) and has shown that within the animal kingdom (2% of the entire biomass), there are many more humans than wild animals and that there is around 40% more livestock than humans.5 This is crazy!

In the city of Otavalo, in northern Ecuador, live the "Otavaleños", an indigenous community with a high cultural identity. The photo was taken during the celebration of "Paukar Raymi" or “flourishing celebration” held every year in the Andean villages. At the "Pawkar Raymi" celebration, "Pacha Mama" or "mother earth" is thanked with two main elements, water and flowers. Photo by Karla Gachet.
Biomass calculated as gigatonnes of Carbon (Gt C) :
1 Gt = 1000000000000 kg
Source: PNAS, 2018. Nar-On, Y.M., et al. The biomass distribution on Earth.

Accrording to FAO, countries, communities and cultures maintaining their traditional food systems not only conserve their local food specialties with the corresponding diversity of crops and animal breeds but are also less likely to suffer diet-related-diseases.4

High up in the Andes of Peru, a community gathers to round up the wild vicuñas to mark and vaccinate them. The women are in charge of feeding everyone, they bring huge pots and pile up wood to cook. They served cooked potatoes and pasta. Photo by Karla Gachet.

A great scientific work safeguarding agricultural and tree diversity to achieve a sustainable global food and nutrition security is being performed by Biodiversity International. One recent publication has shown that a great diversity of cultivated vegetable species (1097) still exist around the world – some of which could have the potential for a widespread diffusion, and many others could fulfil important roles in nutrition at the local context.6

Also, a nice photographic social study performed by Peter Menzel and Faith D’Aluisio is presented in several books that can be viewed online. They show photos and information about food habits and traditions of people around the world. Really worth looking!

Why are we losing traditional food heritage?

”Globalization, industrial development, population increase and urbanization have changed patterns of food production and consumption affecting deeply ecosystems and human diets”4

For different reasons, the global market requires high yields of some foods to be commercialized around the globe at a low price. This need has pushed agriculture towards intensive farming and the cultivation of big areas of monocultures and livestock. The abundance of these “cheap” global foods (cheaper than locally produced foods) has simplified diets and damaged the ecosystem (intensive-use fertilizers, pesticides, antibiotics, deforestation, etc.). We will talk more about this topic, so stay tuned!

Scene at a butcher’s house in Limones, an island of the coast of Ecuador in the Esmeraldas province. The butcher gets up before sunrise and kills a pig. They will sell every part of the animal. Photo by Karla Gachet.

Some very impactful photos showing intensive agriculture were taken by photographer George Steinmetz for his projects: Feeding-9-billion, 21st-century-agriculture and Europes-food-revolution. Worth looking!  

Also, to understand our current food system better, have a look at the YouTube video created by Denis van Waerebeke (available in English with  subtitles in many languages) which explains the global players, dynamics, problems and inequalities affecting food production and what can we do to be part of the solution. Worth watching!

The simplification of diets, the decline in consumption of local nutritional food and the little time/interest we invest in our food (cultivation, selection, preparation) are related to the increase incidence of chronic diseases (nutritionally-poor and energy-rich).  

Poor dietary habits and unhealthy diets are the cause of many nutrition problems today!

Interestingly, before all the scientific and nutritional awareness about food (mostly on individual nutrients), culture mediated the relationship between people and nature, and therefore, people’s relationship with food as well. Industry, wanting to sell more, has undermined the authority of traditional ways of nourishment, impacting how we eat and causing serious harm to human health.

Food as a Public Health Problem

Today, 815 million people are undernourished7 while 1.9  billion are overweight, and from this 650 million obese.8 About half the global population is inadequately nourished (hunger, micronutrient deficiencies and overweight/obesity).9

Children eat breakfast at a preschool in the Kichwa community of San Pedro Sumino deep in the Amazon rainforest in the province of Napo, Ecuador. There used to be a breakfast program to fight malnutrition in Ecuador which was later stopped for lack of funding. Photo by Karla Gachet.

If we think about it, these pandemic nutrition problems are a direct consequence of food waste (link to post 3). Not only does our current food system waste 1.3 billion tonnes per year10, but we waste food when we eat more that we need.

To waste food means not consuming it and overconsumption!

But let’s think about for a minute, our current food system seems to be designed to waste, we need to change this! We need to produce respecting our planet (including technological advancements) and the people working to preserve it (e.g. agroecological farmers, sustainable fishers). It sounds reasonable, don’t you think?

Changes might not be done in the twinkling of an eye, but if we start at home (paying attention to what we buy, from who we buy, at what price, buying seasonally, locally and only what we are going to eat and support the work of farmers producing taking care of the ecosystem (at home or abroad) and politicians willing to take actions in their favor) and talk about it, soon we will be more until we become the majority. .Then, the industry that wants to sell will sell what we want.

Things can change if we really want them to change. We, as individuals, can make the difference, we are already doing it!  

But to change, we need to get informed and understand how things work and what is good for our health which is not disconnected from what is good for our society and our planet.

Healthy Diets

A healthy diet is a diet that must satisfy energy needs (proteins, fats, carbohydrates) and essential nutrients (vitamins and minerals) through food, to attain and maintain optimal health and physiological function.11

Importantly, our bodies need energy (energy requirement) for a series of functions that are essential for life or basal metabolism (e.g. heart beating, respiration, brain activity, cell function and replacement; synthesis, secretion and metabolism of enzymes and hormones, or everything that our smart bodies do on their own), to process food and to perform physical activity. Additionally, at some stages of our lives we need more energy, to allow growth and development during childhood, deposition of tissue during pregnancy and the secretion of milk during lactation.11

So, every day and depending on our body needs (age, gender, body size, body composition, metabolism and physical activity), we need to achieve an energy balance. This happens when the dietary energy intake (what we eat) is equal to the total energy expenditure (what the body consumes).11

Malnutrition occurs when, at long term, the energy balance is not reached  (either too much or too little) and/or there is a deficiency of nutrients.

Sources of energy

Fats and carbohydrates are the main sources of dietary energy, though proteins also provide important amounts of energy, especially when total dietary energy intake is limited.11  

Fausta teaches us to prepare “pisarei” (gnocchi made with old bread). “Pisarei e fasoi” (pisarei with beans) is a traditional recipe in northern Italy. In Italy, before the economic boom, food was not wasted.

Current energy recommendations for a healthy diet suggest a distribution of proteins, fats, and carbohydrates are in the range of 15, 29 and 55 percent daily (conversion factor of 4, 9 and 4 kilocalories per gram (kcal/g) for proteins, fats and carbohydrates).12 Meaning that, if an adult consumes 2000 kcal/day as commonly recommended, the energy intake should be divided in 300 kcal coming from proteins, 580 kcal from fats and 1100 kcal from carbohydrates (or 75 g, 64 g and 275 g) daily.

Additionally, dietary fiber (ca. 2% daily requirement)12 is very important for a healthy diet as it interacts with the gut’s microbiome maintaining or improving the microbiota. In recent years, the awareness about the importance of human microbiota (microorganism within our body) has increased. We will talk more about this topic. Stay tuned!

We need quality and diverse food that provides energy, vitamins and minerals needed to live in a healthy way!  

It’s worth noting that the values recommended for daily energy requirements are used as a matter of convention and convenience as they represent an average of energy needs over certain period of time and that there is a large inter-individual variation.11 So, if we considering the average energy value for everybody (e.g. 2000 kcal), some people could be eating either too much or too little.

It is possible to calculate individual energy requirements12, soon we will perform an exercise to share it with you, don’t miss it!

The Best Diet

There is misunderstanding about the exact components of a healthy diet, and many diets considered to be healthy.

Mennonite sisters from the Santa Rita community in Santa Cruz, Bolivia, make a lot of empanadas for the whole family. The family also has a cheese factory. Members of the community sell them their milk and they make the cheese later on distribute it in the city of Santa Cruz. Photo by Karla Gachet. The full story can be found here

The confusion is probably because the scientific information available is misleading. Many studies have been based only on individual nutrient (e.g. fats, carbohydrates), others have been sponsored by companies which comprises the accuracy of the conclusions, and a lot of knowledge has been spread without really understanding the long-term benefits.

To clarify these misunderstandings, it would help if scientific studies would focus on nutrients in the context of food, food in the context of diet and diet in the context of lifestyle.

Common sense about diet is not common yet!

Luckily, it seems like most recognized diets have a lot in common. This is the outcome of the True Health Initiative, a global community with more than 400 world-renowned health experts. The initiative evaluates scientific information and spread fundamental evidence and consensus-based truths about lifestyle as medicine.

What do most recognized diets recommend?

…“Eat food (true food). Not too much. Mostly plants”… And drink mostly water with it!13

In essence, most diets recommend meals rich in vegetables, fruits, beans, lentils, nuts, whole grains, seeds with or without other elements such as dairy, eggs, meat (consumed in small portions), and prevailing quality over quantity.

Seems easy, right? But, what is true food?

True food refers to food that grows in nature (fruits, vegetable, grains, seeds, nuts, etc.), minimally processed (traditionally or innovatively transformed/conserved (e.g. bread, cheese, yogurt or under vacuum); the less additives the better and even better if they are all natural), sustainable (produced on healthy soil using clean water, respecting the environment and conserving biodiversity), and ethically produced (towards humans and animals).

The production of true food treats the environment, plants, animals and people with respect avoiding intensification (that requires the use of chemical fertilizers, pesticides and antibiotics) and exploitation. 

However, this is not the way most food is produced. The cost of this food is cheap for the consumer but comes at a very high price for the farmers and the environment. It destroys our society, our planet and our health because at the end, it is all connected!  

If we care about consuming true food, we support not only a healthy way of eating but we also build a community that shares values of respect towards nature and humans beings.

In post 2 we talked about food as a good and the environmental connotation of its production. But, food is much more, once it is prepared and placed in the table, it connects us, brings emotion and joy to our life and at the same time it nourishes us!

The house of Abdon Peranchiguay in the island of Teuquelín, Chile, filled up with family the day of his mother’s death anniversary. They cooked up a feast for the invited guests who came to pray. They cooked with a method called curanto, in which they bury burning rocks in the ground. This tradition comes from the Mapuches, one of Chile’s indigenous groups. The only people who live in Teuquelin are of the Peranchiguay family, who arrived about 200 years ago. Photo by Karla Gachet.

Food is meant to be enjoyed! Pleasure is good for our health. If we think about it, people having fun tend to be healthier.

Lifestyle as Medicine

Nowadays, there is a general consensus that health needs to be approach in a holistic way – meaning that food is very important for health but not less important than physical activity, sleep, happiness, low levels of stress and good social interactions. Lifestyle as medicine is not only important for disease prevention but also improves the outcome of many illnesses.

On this regard and remarking on the importance of healthy diets have a look to the YouTube video What is the best diet? with Dr. Mike Evans from the Reframe Health Lab. Many nice videos on his website that are really worth watching!

Conclusions

Many factors influence our health – and a very important one is what we eat.

It is important to eat in a sustainable manner, prevailing quality over quantity, thinking of our health and our planet, respecting all living beings, and safeguarding local food traditions and biodiversity!!

Let’s remember that changes in the food system can come either from above (e.g. politics-related work, activism) or from below (e.g. food demand, health literacy, label reading ability).

The industry produces what the consumer wants! So, we, the consumers, are able to change things if we really want!

We can start caring about what we eat in an active way. Let’s prepare our own food. Let’s start cooking!!

By M. S. Gachet

REFERENCES:
1 WHO. Healthy diet.
2 FAO, 2016. Plates, pyramids, planet.
3 EAT-Lancet Commission, 2019. Food, Planet, Health. Healthy Diets From Sustainable Food Systems.
4 FAO. Biodiversity and Nutrition a common path.  
5 PNAS, 2018. Nar-On, Y.M., et al. The biomass distribution on Earth.
6 Biodiversity International, 2018. Meldrum, G. et al. Issues and Prospects for the Sustainable Use and Conservation of Cultivated Vegetable Diversity for More Nutrition-Sensitive Agriculture.
7 UN. Nutrition.
8 FAO. Obesity and Overweight.
9 FAO, 2019. The State of Food Security and Nutrition in the World.
10 FAO, 2013. Food Wastage Footprint. Impact on Natural Resources.
11 FAO/WHO/UNU, 2001. Human energy requirements. Report of a Joint FAO/WHO/UNU Expert Consultation.
12 FAO, 2003. FAO Food and Nutrition Paper 77: Food energy – methods of analysis and conversion factors. Chapter 3: Calculation of the Energy Content of Foods – Energy Conversion Factors. 
13 Pollan, M. New York Times. January 28, 2007. Unhappy Meals.