Food pyramid: How much do you know about it?
Published: 6 September, 2023 | 14'
The food pyramid is a fundamental guide for incorporating healthy eating into our daily lives. It is a widely known and used reference, but do we really know everything about it? In this article, we will tell you about its origin, evolution, and adaptation to the dietary needs of other countries.
What is the food pyramid and why does it matter?
In 1992, the International Conference on Nutrition established the need for tools and strategies to disseminate food guidelines and regulations to the population, with the aim of preserving overall health based on a balanced diet.
From this requirement arose the so-called "food pyramid," which is nothing more than a graphical representation, in the form of a triangle, of the dietary guidelines recommended by nutrition authorities.
The importance of the food pyramid lies in its ability to provide a quick and easy-to-understand guide to healthy eating. How does it do this? By indicating the foods (quantity and type) that should be consumed daily to maintain good health, and especially to prevent or reduce the risk of developing eating disorders.
Basic nutrient groups for a healthy diet
It is necessary to inges specific quantities of nutrients daily to contribute to optimal health. These nutrients are part of a healthy diet and consist of proteins, fats, carbohydrates, vitamins, and minerals, which must be obtained from a variety of foods, as it is not possible to obtain all the necessary nutrients in the right amounts from a single food.
Let's take a look at each of them:
Carbohydrates
Carbohydrates represent more than half of the calories we consume, providing 4 kcal/g, and are found in the majority of the foods we eat. In general, plant-based foods are the ones that provide the most carbohydrates to our diet (fruits, vegetables, legumes, etc.), while animal sources provide them in dairy products and liver (in the form of glycogen).
Carbohydrates are composed of sugar units and can be classified as either "simple" (glucose, fructose, sucrose, lactose, and maltose; for example, sugar from fruits) or "complex" (starches, glycogen, fiber, among others; for example, the starch contained in potatoes). Simple carbohydrates are rapidly absorbed and should be consumed in moderation, while complex carbohydrates are absorbed more slowly and are more nutritionally adequate.
Fats
Fats or lipids are the most energy-dense sources available to our bodies, providing 9 kcal/g. They are stored in various parts of our bodies, as they constitute our energy reserves, and are also a vital component of all cells and tissues. Examples of these fats are triglycerides and cholesterol, which, in the right amounts, play an important role in many processes in our body. While our biochemical processes can convert fatty acids from carbohydrates and proteins, certain fats (such as fat-soluble vitamins like vitamin D) and essential fatty acids (such as linoleic acid) cannot be produced in our bodies.
It is worth noting that fats are divided into saturated, monounsaturated, and polyunsaturated based on their chemical structures. From a nutritional and health standpoint, monounsaturated fats (such as olive oil and omega 9) and polyunsaturated fats (such as fish oil and omega 3 and 6) are the most appropriate.
Proteins
Proteins are the most abundant components in cells and are essential for their structure and function, as well as participating in many metabolic processes. Like carbohydrates, proteins provide 4 kcal/g, but more energy is required for their absorption and processing. They are made up of amino acids (there are 20 for humans), which are small structures that combine to form different proteins, such as collagen and hemoglobin.
Of these 20 amino acids, 9 are considered essential because they are either not produced by our bodies or are produced in very small quantities. Examples of essential amino acids include tryptophan, leucine, lysine, and methionine. Due to this, protein intake should focus more on quality than quantity. In the case of plant-based proteins, diverse sources such as nuts, vegetables, and grains should be chosen to provide these 9 essential amino acids. In the case of proteins of animal origin, such as dairy products, eggs, and fish, they contain all of these amino acids and are recommended.
Vitamins
Vitamins are essential, non-caloric nutrients that are necessary in small amounts in the diet. They are not produced by our bodies and their presence determines whether other nutrients are digested, absorbed, metabolized, or incorporated into body structures. Vitamins can come from both plant and animal sources, such as fruits, cereals, dairy products, fish, and poultry, among others.
Vitamins are divided into two classes: fat-soluble (which dissolve in fats) and water-soluble (which dissolve in water). Fat-soluble vitamins (i.e. A, D, E, and K) are mainly found in lymph and are stored in the liver or adipose tissue. Water-soluble vitamins (i.e. C and B) are available in the bloodstream and are generally not stored in tissues, being easily excreted in urine.
Minerals
Minerals are essential, natural, inorganic, non-caloric nutrients that represent about 5% of our body. Like vitamins, they are not produced by our bodies and are stored after ingestion. They participate in many metabolic pathways, such as the production of red blood cells (iron is incorporated), and are vital for muscle, bone, water balance, hormone production, among others.
Minerals are classified as macrominerals and trace elements. Macrominerals, such as calcium and potassium, need to be consumed in an average intake of more than 100 mg/day, while trace elements, such as iron, zinc, and selenium, require an intake of less than 100 mg/day.
Fiber
Fiber is a complex carbohydrate that does not contain starch and is poorly digested. Therefore, fiber passes through the human body intact without providing energy for use, except for those fibers that can be fermented by intestinal microflora in the colon. Examples of foods rich in fiber include whole grains, legumes, and fruits, among others.
Fiber is important because it promotes satiety and increases fecal volume, which is beneficial for weight control and intestinal health.
How has the food pyramid evolved?
When the first version of the food pyramid was presented in 1992, it included cereal, bread, rice, and pasta at the base, followed by vegetables (3-5 times/day) and fruits (2-4 times/day). The next level consisted of protein-rich foods, and at the top were fats, oils, and sweets, which should only be consumed occasionally.
Over time, scientific research in nutrition, changes in eating patterns, economic reasons, globalization, climate variations, environmental impact, among others, have led to adaptations of this pyramid by adjusting recommendations to the characteristics of populations at the regional or national levels. Let's look at some of these adaptations and the arguments for their implementation.
Swedish Pyramid: the origin of it all
During the 1970s, Sweden faced a crisis caused by rising food prices. The government commissioned the National Food Administration to design a strategy to address this situation. They developed a triangular graphical representation because it provided a better visualization of portion sizes, recommending three levels of basic and complementary foods based on their affordability for the population. At the base of the triangle were milk, cheese, margarine, bread, cereals, and potatoes, followed by fruits and vegetables as complementary to main meals. The top tier consisted of meat, fish, and eggs.
Currently, in Sweden, they have modified the graphical representation to a traffic light system. Green: eat more vegetables, fruits, berries, fish, seafood, nuts, seeds, and exercise. Yellow: consume whole grains, healthy fats, and low-fat dairy products. Red: eat less red and processed meat, salt, sugar, and alcohol. This type of traffic light system, along with a plate, is also included on food labels.
MyPyramid: another twist on nutrition
In 2005, the United States Department of Agriculture (USDA) published the Dietary Guidelines Report along with a graphical representation called MyPyramid. This guide recommends dietary patterns and nutrient intake based on age, sex, and activity levels. It was in effect until 2011.
It defined eight levels: personalized physical activity based on functional groups, with recommended durations of 30-60 minutes per day; six food groups: whole grains (27%); vegetables, especially dark green ones (23%); fruits, excluding juices (15%); oils from fish, nuts, and vegetables (2%); dairy (23%); and proteins from lean meats, low-fat dairy, beans, peas, nuts, and seeds (10%). Finally, there was a very narrow discretionary calorie allowance that included items such as sweets, alcohol, or other additional foods from any group.
MyPlate: a more flexible dietary option
The USDA updated its food pyramid with the MyPlate guide; while MyPyramid focused on variety, moderation, and proportion, MyPlate focuses on variety, portion size, and nutrition of foods.
The MyPlate Plan is a much more visual and easier-to-implement format that shows the goals of the food groups, what and how much to eat, within the recommended calorie intake. Similar to the previous guide, it tailors its recommendations based on age, sex, physical activity level, and now includes weight and height.
The recommended food groups for each quarter of the plate are: fruits, which should be seasonal as they contain more nutrients; vegetables of different colors to obtain a wide variety of nutrients; grains, preferably whole grains; protein, from animal sources such as beef, pork, poultry, or seafood, and from plant sources such as nuts and beans. Dairy should be consumed with every meal.
The "Healthy Eating Plate" from Harvard
The Healthy Eating Plate from Harvard is based on various epidemiological studies on dietary variables and their impact on cardiovascular health and cancer. Based on these results, nutrition experts from Harvard developed a guide focused on the frequency of consumption of a group of foods rather than the amount, creating an index of diet quality, the Alternate Healthy Eating Index.
This index consists of nine components: cereal fiber, fruits, vegetables, nuts/soy, white and red meat ratio, polyunsaturated and saturated fatty acid ratio, trans fats, multivitamins, and alcohol. When combined with data from the Harvard study, it was associated with a lower risk of chronic diseases. Its recommended food intake is represented through a plate that indicates that half of the plate should consist of vegetables and fruits with a variety of colors; a quarter should consist of whole grains (such as wheat, barley, quinoa, oats, etc.), which have a more moderate effect on blood sugar and insulin; and the remaining quarter should consist of protein from fish, poultry, legumes, and nuts, limiting red and processed meats. Accompanying the Harvard plate is the recommendation to consume healthy plant oils such as olive oil, corn oil, sunflower oil, and others, while avoiding partially hydrogenated oils. It also recommends drinking water, coffee, or tea, consuming one to two servings of dairy products per day, and limiting sugary beverages. The final recommendation is to stay active to maintain a healthy weight.
Differences between the traditional food pyramid and the one recommended by SENC
The Spanish Society of Community Nutrition (SENC) has designed a food guide for the Spanish population based on a chromatic pyramidal structure. The guide has been revised and updated since the year 2000 by a group of experts who review the available evidence in the field of nutrition, considering the guidelines of the WHO and the Spanish public health policy, with a focus on the adequacy of the diet, weight control, and increased physical activity to prevent and manage chronic diseases.
To this end, during the III World Congress of Nutrition and Public Health in 2014, SENC developed a revised and consensual proposal for the Food Guidelines. SENC emphasizes that this guide respects the current dietary model of the Spanish population, aiming to help individuals organize their eating process more efficiently, considering all its nuances, including sustainability. What recommendations does the guide contain? Let's see.
The base of the pyramid consists of five areas: physical activity (30-300 min/week depending on the population group), emotional balance (promoting a healthy relationship with food), weight control, culinary techniques that preserve nutritional properties, and adequate fluid intake (2.5 liters/day). The second level recommends the intake of whole foods such as grains, bread, legumes, etc., according to the level of physical activity. The following level suggests sufficient and frequent intake of vegetables, fruits, and olive oil. These two levels make up the main food group for each main meal. The fourth level is for a varied daily intake that includes dairy products, fish, lean meats, legumes, eggs, among others. The remaining two levels are for occasional consumption of fermented beverages (i.e. wine), red meats, cured meats, pastries, sweets, salty snacks, etc.
Do you know how many variations of the food pyramid there are?
In recent years, there has been extensive research on dietary options, nutrition, health, and the environment. The factors that have driven this activity are that many countries have experienced decisive nutritional changes that have led to populations consuming a diet characterized by increased intake of animal proteins, processed foods, hydrogenated fats, and decreased intake of fiber, coupled with sedentary lifestyles. These factors contribute to high rates of obesity and chronic diseases such as diabetes.
Therefore, food guidelines are evolving each day and are more tailored to each country or region, aiming to find cost-effective solutions to address nutritional problems, considering the specific characteristics of the population in terms of habits, traditional and local food resources, economy, and health indicators.
The Mediterranean diet
The Mediterranean diet has produced the most scientific evidence of its direct health benefits. It was declared an Intangible Cultural Heritage of Humanity by UNESCO in 2010: it is not just a diet, but also a tradition and a symbolism of the Mediterranean region, its cuisines, and its people, as well as a healthy way of life.
Its importance was demonstrated in a large-scale study conducted by Cresta in 1969, which revealed that the diets of Mediterranean regions were characterized by a high adult life expectancy, low obesity rates, low rates of coronary heart disease, certain types of cancer, and other related chronic diseases. The other major findings were a much higher consumption of cereals, vegetables, fruits, and fish and a much lower consumption of potatoes, meat, dairy products, eggs, and sweets, as well as a lifestyle that included regular physical activity, food preparation, and socializing during meals.
The current Mediterranean pyramid (see figure) indicates foods based on their importance, type, and frequency, incorporating 5 key elements at the base for a healthy state: moderation, related to frugality and portion sizes; socializing, emphasizing the social and cultural value of a meal beyond its nutritional aspect; cooking, with sufficient time dedicated to food preparation; sustainability, involving the development of a sustainable diet model for current and future Mediterranean generations; and physical activity, recommended as a basic complement to the diet to balance energy intake, maintain a healthy body weight, and provide many other health benefits.
The Australian Food Pyramid
The graphic representation is based on the Australian Dietary Guidelines of 2013, which summarize the types and proportions of foods recommended for daily consumption to maintain good health. It is important to note that it includes the five main food groups as well as healthy fats, and the layers of the pyramid are based on the recommended food intake for people aged 19 to 50 years; however, the proportions and placement of each food group are generally applicable to all age groups from 1 to 70 years.
The layers of the Australian pyramid consist of a foundational layer containing legumes, vegetables, fruits, and whole grains, covering 70% of our intake; the middle layer focuses on protein-rich foods: reduced-fat dairy, fish, lean meats, nuts, seeds, and legumes. The top layer includes healthy unsaturated fats from plant sources (such as olive oil, nuts, or seeds) or from animal sources such as fish, while avoiding foods containing saturated fats and trans fats. The pyramid also recommends choosing water for hydration and limiting sugar and salt consumption.
Vegetarian Pyramid
These guidelines were developed after extensive experimental and epidemiological research on the food habits of vegetarian populations, and a committee of experts proposed an appropriate nutrient intake to achieve optimal health. The key principles for determining this pyramid are variety and abundance in the consumption of plant-based foods, reducing processed/refined products, including animal protein sources if part of the vegetarian eating pattern (i.e. dairy products), and choosing suitable Sources of healthy fats.
The Spanish Vegetarian Union has designed a pyramid based on these principles, recommending the following intake: the first layer consists of half the plate being vegetables and greens (fresh, seasonal, and locally produced), one-fourth consisting of whole grains and tubers (i.e. cereals, couscous, sweet potatoes, cassava, etc.), and fruits (fresh, seasonal, and locally produced; whole, sliced, or in pieces); the second layer consists of one-fourth of protein-rich foods (i.e. lentils, chickpeas, eggs, soy-based fermented products, etc.), and the top recommendation is to take vitamin B12 supplements and iodized salt. Olive oil and water accompany these layers.
Cardiovascular Health Pyramid
The cardiovascular health pyramid was developed following a study (DASH -Dietary Approaches to Stop Hypertension-) that evaluated the impact on hypertension of three different diets, one of which is a combination of the others called DASH. The DASH diet proved effective in reducing hypertension and combined fruits, vegetables, reduced-fat dairy products, fish, and whole grains, with a reduction in the intake of oils, red meats, sugars, and sodium salt.
The plan of the cardiovascular health pyramid (based on the DASH diet), recommended by the Spanish Heart Foundation, associates the servings of each food group per day, based on a wide variety of vegetables, fruits, whole grains, and dairy products as the fundamental principle of the graphic. It then continues with olive oil, spices, nuts, legumes, fish, poultry, and eggs. Finally, it includes red meats and processed meats as an occasional intake recommendation.
Inverted Food Pyramid or the Triangle of Nutrition
Another pyramid currently used is the inverted pyramid from Belgium. This graphic focuses on foods that should be the primary part of our diet, occupying the wide base and the top of the pyramid: vegetables and fruits, followed by legumes, whole grains, vegetable protein, potatoes, and wholemeal pasta. Healthy fats (quality oils, nuts) are also included in this first group.
The second group consists of regularly consumed foods such as fish, fermented dairy products, eggs, chicken, and white meats, while the top layer, for occasional consumption, includes butter and red meat. In addition, alcohol, soft drinks, processed products, pastries, sweets, chocolate, among others, are excluded from the pyramid or recommended to be consumed as little as possible.
Conclusion
As we have read, food and diet are largely responsible for our health. The type of food, its quantity, and its quality in terms of nutrients, calories, and positive impact on health, especially cardiovascular health, are all important.
Food guidelines issued by nutrition authorities are diverse and must be adjusted to the idiosyncrasies of the country or region and the changing population, as well as aligned with the goals of preventing chronic diseases. Therefore, the best guidance for a healthy and balanced diet should be provided by health institutions and professionals with expertise in nutrition.
