The quest for food is as old as the beginning of living system on earth. When first organism appeared, then it was the beginning of the fight for food. Food affects not only the fate of an organism, but it shaped the civilisation, the war between tribes or nation, and also creates the so-called humanisation of human being.

 

 

 

 

 

 

 

 

 

 

 

 

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Introduction to Food

Good and healthy food is not a jargon, it is a life style, a decision that we make to get a valuable and sustain life. Consuming food is not for the sake of the taste that will last for only a few seconds during its journey through our mouth to the digestive system. Food that we consume will generate energy and many precursor molecules for the synthesis of many important macromolecules required to sustain the life of the cells and thus our body. What we consume will determine whether we will have a healthy, strong and beautiful body, or just a waste bin that creates many blockages in the blood artery and end ups in stroke, heart attack, or any physiological problems.

Breakfast

 

What is Food ?

Food is generally classified as anything in any form, liquid, solid, or semi-solid, that will give nutrition and nourish the body when it is consumed.  Based on the function and role to the body, food can be classied into four basic roles: (1) yields energy, (2) builds the body, (3) provides protection and regulating the body, (4) maintains health.  The energy-yielding food includes food rich in carbohydrate, fat (lipid) and protein. One gram of carbohydrate equals to 4 calorie, one gram of fat equals to 9 calorie, and one gram of protein gives 4 calories. What is calorie ? This term may confuse many people. In essence, calorie is a unit of energy. Anything that contains energy has calories. Calorie is defined in two types, small calorie (symbol: cal) is a unit of energy required  to raise one gram of water by one degree Celcius, and large calorie (Cal or kcal) is a unit of energy required to raise one kilogram of water by one degree Celcius. Therefore, one kcal equals to 1000 calories. It is important to note that in food labeling, the unit used is 1000 small calories or one kcal. Therefore, a food that is labeled as having 100 calories means that it contains 150,000 calories.

 

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Nutrition

Food and nutrition are two issues that are fully related like two sides of the same coin. We consume food to give nutrition to our body. What is nutrition ? Nutrition refers to the science of how living organisms obtain, uptake, metabolise food to fulfill all the processes required for the existence of living organisms. Michele McGuire and Kathy Beerman in their book: Nutritional Science. From Fundamentals to Food (Wadsworth, Cengage Learning, 2013) describe that scientists who study nutrition, nutritional scientists, can be found in many disciplines, including immunology, medicine, genetics, physiology, biochemistry and many other disciplines, while dietitians are nutrition professionals who work to help the people in planning the diet and food choices to support a healthy life style.

 

Fruits

Which Food ?

There are so many foods in the supermarket, many of them are wrapped in a beautiful eye-catching plastic or box to attract the consumers. In general there are two types of food available in the market, fresh and processed food. Fresh foods are foods that have not undergone any cooking except for basic treatment, such as cleaning or washing. Apples, for example, that have been coated with wax or any coating materials, can not be regarded as "fresh", they have to be classified as "processed foods". Processed foods, on the other hand, are foods that have been treated, either just for increasing their shelf-life, or by cooking, frying, or any cooking process to make food ready for consumption.

Food Composition

Basically, food is the source for energy and molecules for the synthesis of many building blocks of an organism, including human cells and tissues. However, it should be noted that not all components in a given food are nutrients. In general, scientists classify nutrients into six categories: carbohydrate, protein, fat, mineral, vitamins, and water. Main source of energy comes from carbohydrate, in the form of simple sugar to complex molecules such as starch. However, fat and protein can also become the sources of energy when the carbohydrate is not present in the food we consume. Carbohydrate also serves as the sources of many precursors (molecules that become the foundation structure of more complex biological molecules) when it is metabolised by the organisms. Many types of molecules which build the cells can be classified into simple groups of molecules or macromolecules, such as protein, lipid (fat), vitamins, minerals. Some foods contain mostly carbohydrate, such as rice, cassava, potato, despite the fact that they may also contain some proteins, minerals, or other molecules in minute amounts. On the hand, some foods contains mostly protein, such as meat, although meat also contains carbohydrate molecules albeit at a much lower concentration than protein as the main component of meat. In addition to carbohydrate, protein, and fat, some foods also contain minerals, vitamins, or other molecules.

Basically almost every food that we harvest from the field contains carbohydrate, protein, fat, and some minerals, despite the fact that each food has the main component, either as the main source of carbohydrate, protein, or fat. Consumption of varied foods will provide a more complete source of nutrition required by the body.

Despite the fact that our body can use all kinds of nutrients, we need only some of the nutrients in the food. Therefore, food nutrients can be categorised into three groups: (1) essential, (2) non-essential, and (3) conditionally essential, nutrients. Essential nutrients are nutrients that are absolutely required by the body to fulfill the utmost process for keeping the life. Essential nutrients must be present in the diet as our body may not have the ability to synthesise or can not produce in adequate amounts. Non-essential nutrients are nutrients that can be produced by our body in adequate amounts to satisfy the physiological requirement. Hence, we do not necessarily have to consume non-essential nutrients. Many foods contain essential and non-essential nutrients. However, acoording to Michele McGuire and Kathy Beerman in their book: Nutritional Science. From Fundamentals to Food (Wadsworth, Cengage Learning, 2013), non-essential nutrients may become essential under certain condition. Such nutrients are called as conditionally-essential nutrients.

Nutrients can also be classified based on the amount required by the body: macronutrient, required in large quantities (over one gram per day), such as water, carbohydrate, protein, and lipid, and micronutrient, required in small quantities (microgram or milligram per day), such as micronutrient iron. Nutrient can also be classified by organic nutrient or inorganic nutrient. Nutrient is classified as organic if it contains carbon atoms bonded to hydrogen atoms or other carbon atoms, while the inorganic nutrients do not contain such carbon atoms bonded to hydrogen atoms, such as water and minerals. Therefore, carbohydrate, protein, lipid and vitamins are organic nutrients, and so other foods are organic. However, in terms of the production system, food may be categorised as organic if it is produced and processed using organic system of production as described by organic standards, such as do not use inorganic pesticides or fertilisers.

Food and Human Health

No human being and all sort of living organisms can live and survive without food. Food, and the right environmental condition, will determine how a particular organism strives and maintains the life and, to a certain extent, will develop into a more complex living organisms. The quality, and the right quantity, of food taken up by a human being will lead the human body into a specific physiological state. Food provides energy, building block molecules for growth, synthesis of new cells to replenish the dead cells, protection against disease, and even may determine the psychological status of a person. Nutritional deficiencies have become major problem in several less developed countries. However, health problem may also arise from poor diet choices which results in the imbalances in the uptake of important nutrients required by the body. Obesity, cancer, diabetes type 2, heart disease, osteoporosis are some examples of health problem as a result of poor or imbalanced diet.

Michele McGuire and Kathy Beerman in their book: Nutritional Science. From Fundamentals to Food (Wadsworth, Cengage Learning, 2013) also explain that, in addition to the macro- and micronutrients, it is now known that plants and animals also contain substances which also contribute to human health. They are phytochemicals (phytonutrients) originated from plants, and zoochemicals (zoonutrients) found in animals. Another type of food that is now becoming increasing popular is functional food, containing enhanceed amounts of traditional nutrients and phyto- or zoonutrients, such soy milk. Fruits and vegetables are part of healthy diets that should be included in the list of the menu prepared for everyday meal.

Food and Life

Undoubtedly, food is as important as the life itself. Without any food, there will be no life. Finding food has become the main driving of human civilisation. Human civilisation was shaped and transformed by the way human being finds the food. Simple organisms find the food through biochemical reactions which in many cases do not involve any visual process. Human being, on the other hand, finds the food based on biochemical reactions in the body as well as visual, and even emotional stimuli. Therefore human being achieves physical, emotional, and cultural development throughout the time line of historical quest for food.