Food and Nutrition; Definitions, History and Nutrients

What is Food?

The Turkish Language Association’s dictionary defines food as “any edible substance suitable for nourishment”. This definition, however, is not sufficient to describe food: taken literally, it does not account for drinkable foods.

Similarly, medicines could qualify as food under this definition, although medicines are not food. Food science sources do not offer a single, universally accepted definition either. Definitions generally focus on the physiological effects of food.

Food is not consumed solely for its physiological effects. People may eat something they find delicious simply because they want to, even when they are neither hungry nor thirsty.

People can therefore be said to have a need for the pleasure of taste. If food were consumed only to satisfy hunger and thirst, there would be no need to expand the already extensive variety of foods. A definition of food should also take this aspect into account.

In its broadest sense, the term “food” encompasses foods and beverages that contain the energy and/or building blocks needed for physiological functions and are consumed to satisfy hunger, thirst and the desire for enjoyable flavors.

What is Nutrition?

The absence of a clear, shared definition of food also applies to nutrition. Existing definitions emphasize its physiological aspects while overlooking the important role of taste and the pleasure of eating. Yet these have a major influence on how we eat.

We often eat for taste and pleasure as well as out of necessity. An individual’s aims and activities also influence nutrition. For example, an athlete’s eating plan and that of a student preparing for an examination differ according to their goals.

In this context, nutrition can be described as the oral intake of foods that a person must consume to sustain life and/or wishes to consume.

History of Nutrition

Archaeological evidence indicates that before the Neolithic period, humans were hunter-gatherers. We can therefore infer that they ate the meat of hunted animals and foods collected from nature, such as eggs, honey, fruit and nuts.

This was a time when finding food was a matter of life and death. It can also be regarded as a period when food processing began, as illustrated by the discovery of fire and the cooking of meat.

During the Neolithic period (8000–5000 BC), the transition from hunting and gathering to settled life brought about a major transformation in human societies.

People began to domesticate plants and animals as food sources, giving rise to agriculture. Archaeological evidence indicates that cereals and the meat, milk and eggs of domesticated animals were consumed.

Over this approximately 3,000-year period, the development of human civilization accelerated.

Settled life brought many advances, including protection from environmental and climatic conditions and a more accessible, consistent food supply. The foundations of modern civilization can be traced to the Neolithic period.

Before the Neolithic period, people lived on what they could find and hunt. Farming then enabled them to produce more food than they could consume. This surplus very probably encouraged trade.

This raises an important question: how did people store and preserve surplus meat, milk and grain under the conditions of that time?

Today, meat can be stored for long periods in cold stores or freezers, and milk can be dried into powder for long-term storage. Modern transport networks allow food to travel long distances.

Practical, safe packaging is also available today. But what containers did people use in the past, and how did they preserve their food? These questions lead us to the development of food processing techniques and fermented foods.

During the Neolithic period:

• The meat was dried in the sun and salted,

• The bread was produced by turning the grain into flour,

• Milk was put in earthen pots and yogurt was discovered, milk became cheese in the tripe that was used as a bag,

• Butter was produced by separating milk fat; it was used both as food and as an ointment,

• Wine and vinegar were probably also produced.

• This period brought a major increase in dietary variety and a transformation in how people ate.

In the Chalcolithic Age (5000–3500 BC), the variety of foods consumed continued to increase, although developments were less extensive than those of the Neolithic period.

During this period, the Cretans were skilled in producing olive oil, and sugar cane began to be used as a sweetener in place of honey. Spices and medicinal plants also began to be consumed and traded.

This suggests that people had largely secured their food supply and were turning to greater variety to improve flavor.

The discovery of bone fishing hooks dating back 5,000 years, the raising of mullet in saltwater ponds by the Chinese and the development of navigation on the Nile by the Egyptians indicate that seafood became a significant part of the human diet in Antiquity (3500 BC–AD 476).

Sugar cane consumption spread to different regions during this period. Around AD 350, people in India discovered how to obtain sugar crystals from sugar cane.

Although trade developed, the variety of foods people could consume remained limited by their environment and climate. Since the discovery of the Americas in 1492 had not yet occurred, the civilizations of that period lacked many foods widely enjoyed today, such as potatoes, eggplants and tomatoes.

A joke illustrating this point is that Mehmed the Conqueror died without ever tasting menemen, the Turkish dish made with eggs, tomatoes and peppers. These vegetables were not present in Ottoman cuisine until the 1700s. Nevertheless, Ottoman cuisine also contributed distinctive delicacies such as Turkish delight.

The Industrial Revolution (1760) can be said to have influenced human nutrition at least as much as the Neolithic period. Advances in technology and science greatly increased food production, packaging, storage and transport capacity.

These developments extended the shelf life of food and enabled products made in one part of the world to be transported quickly over long distances without spoiling.

In the 2000s, food processing advanced to another stage. Specific substances, such as vitamins, minerals and fatty acids, could be isolated from foods and offered as supplements.

Dietary approaches based on different beliefs, such as eating only plant foods, have also developed and become popular. Research into laboratory-grown meat is another important development. These changes suggest that major shifts in diets and the types of foods consumed may occur in the near future.

Although the Industrial Revolution and modern communication have made diets more globalized and uniform, humans still consume an enormous variety of foods, from grasshoppers to mussels and from spaghetti to kebabs.

History of Food Science

Plants believed to have medicinal effects were traded during the Chalcolithic Age (5000–3500 BC). This suggests that people had discovered that certain foods served purposes beyond satisfying hunger and thirst, and consumed them for those purposes.

The saying of Hippocrates (460–377 BC), “Let food be your medicine and medicine be your food”, also illustrates attempts to explain food and nutrition within the knowledge available at the time. In the 10th century, Ibn Sina (980–1037) emphasized eating foods according to the season and warned against overeating.

Although the composition and functions of foods were still poorly understood, their important effects on health were recognized. Until the 19th century, foods were thought to consist of a single nutrient.

In the 19th century, it was discovered that foods contained components with different structures, such as carbohydrates, fats and proteins, rather than a single building block. These components were not yet well understood, however, and were thought to serve only as sources of energy.

After the 1850s, their different functions and properties began to be discovered. It also became clear that foods contained minerals and vitamins in addition to carbohydrates, proteins and fats.

Important milestones in the development of nutrition science include the work of:

• Lavoisier (1743–1794), who explained aspects of fermentation chemistry and principles for analyzing organic compounds;

• Gay-Lussac (1778–1850), who introduced analytical methods for determining the proportions of carbon, hydrogen and nitrogen in dried vegetables;

• Berzelius (1779–1848), who introduced the term “protein”, and Mudler (1802–1880), who studied the amino acids produced by protein breakdown during the same period;

• Liebig (1803–1873), who divided foods into nitrogen-containing and nitrogen-free groups in 1842;

• Louis Pasteur (1822–1895), whose research on microorganisms helped explain fermented foods and the relationship between food and microorganisms.

Nutrients

Foods contain major and minor components. Four major components—water, carbohydrates, proteins and fats—generally make up 99% of a food. Minor components are present in much smaller amounts but have important physiological effects.

Macronutrients:

1. Water (see Water and Health and Water in Foods)

2. Carbohydrates (see Nutritional importance of carbohydrates and Carbohydrates)

3. Proteins (see Nutritional importance of proteins and Proteins)

4. Lipids (see Nutritional importance of fats and Lipids)

Micronutrients:

1. Vitamins (see Vitamins; Health and Nutrition)

2. Minerals (see Minerals; Health and Nutrition)

3. Other micronutrients (food additives, phenolic compounds, natural toxic compounds, compounds formed during food processing, microorganisms, etc.)

The compositions of some foods are given in the table below. Some of the minerals and vitamins are included in the table as an example. Each nutrient will be covered more extensively in the respective chapters. (Fe; Iron, Mg; Magnesium, Ca; Calcium, mg; milligram, IU; international unit. Values are average.)

References

Raymond, J. L., & Morrow, K. (2023). Krause ve Mahan Besin ve Beslenme Bakım Süreci (16. baskı; G. Akbulut, Çev. Ed.). Nobel Tıp Kitabevleri.

Sencer, E., & Orhan, Y. (2005). Beslenme. İstanbul Medikal Yayıncılık.

Aksoy, M. (Ed.). (2022). Beslenme Biyokimyası (7. baskı). Ankara Nobel Tıp Kitabevleri.

Saldamlı, İ. (Ed.). (2021). Gıda Kimyası. Hacettepe Üniversitesi Yayınları.

Bilişli, A. (2012). Gıda Kimyası. Sidas Medya.

Türk Dil Kurumu. (n.d.). Gıda. Güncel Türkçe Sözlük. Türk Dil Kurumu.

World Health Organization & Food and Agriculture Organization of the United Nations. (2024). What are healthy diets? Joint statement by the Food and Agriculture Organization of the United Nations and the World Health Organization. WHO & FAO.

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