544
25.2 Types of Nutrients
Nutrients can be classified as essential and non–essential; energy yielding and non–
energy yielding; as well as macro and micronutrients. Essential nutrients are nutrients that the body cannot produce in sufficient quantities and must be obtained
through the diet. These include carbohydrates, lipids and proteins, certain vitamins
and minerals, and water. Non–essential nutrients on the other hand can be made by
the body and are obtained usually from sources other than foods. Biotin and vitamin
K produced by gastrointestinal bacteria, cholesterol produced by the liver, and vitamin D produced in the presence of sunlight in our body are some examples of non–
essential nutrients. A person consuming a balanced diet is likely to have access to
most of the essential and non–essential nutrients. Nutrients may also be classified as
energy yielding (carbohydrates, protein and lipids), and non–energy yielding (vitamins, minerals and water). The energy–producing nutrients are metabolized by the
body to release energy (Marcus 2013). In general, the body requires two types of
nutrients: macronutrients and micronutrients. Macronutrients, like carbohydrates,
fats and proteins are needed by the body in large quantities whereas, micronutrients,
like vitamins and minerals, are needed by the body in smaller portions (Campbell
2017). If a person avoids foods to restrict calories on a regular basis, he/she runs the
risk of nutrient deficiencies in the body (Marcus 2013).
25.2.1 Macronutrients
Macronutrients, the primary building blocks of our diet are found in almost every
food item. During metabolism these are processed into chemical energy which are
then converted into cellular energy for utilization by the body to perform bodily
functions (Mahan and Raymond 2016; Titchenal et al. 2018). There are three main
macronutrients: lipids, carbohydrates, and proteins.
25.2.1.1 Lipids
Lipids are chemically defined as water insoluble (lipophilic or hydrophobic) substances that are esters of fatty acids, phosphoric acid etc. They are found in eggs,
shellfish, animal fat, soya products, olive oil, milk and coconut fat (Table 25.1).
Together with carbohydrates, sterols and proteins, lipids in the form of fats and oils
are the main constituents of living cells. Fats are glycerides of predominantly saturated fatty acids and solid at room temperature, whereas oils are glycerides of unsaturated fatty acids and exist in liquid form. These are abundantly found in butter,
oils, meats, dairy products, nuts, seeds, and in many processed foods, and execute
K. Sharma et al.
25.2 Types of Nutrients
Nutrients can be classified as essential and non–essential; energy yielding and non–
energy yielding; as well as macro and micronutrients. Essential nutrients are nutrients that the body cannot produce in sufficient quantities and must be obtained
through the diet. These include carbohydrates, lipids and proteins, certain vitamins
and minerals, and water. Non–essential nutrients on the other hand can be made by
the body and are obtained usually from sources other than foods. Biotin and vitamin
K produced by gastrointestinal bacteria, cholesterol produced by the liver, and vitamin D produced in the presence of sunlight in our body are some examples of non–
essential nutrients. A person consuming a balanced diet is likely to have access to
most of the essential and non–essential nutrients. Nutrients may also be classified as
energy yielding (carbohydrates, protein and lipids), and non–energy yielding (vitamins, minerals and water). The energy–producing nutrients are metabolized by the
body to release energy (Marcus 2013). In general, the body requires two types of
nutrients: macronutrients and micronutrients. Macronutrients, like carbohydrates,
fats and proteins are needed by the body in large quantities whereas, micronutrients,
like vitamins and minerals, are needed by the body in smaller portions (Campbell
2017). If a person avoids foods to restrict calories on a regular basis, he/she runs the
risk of nutrient deficiencies in the body (Marcus 2013).
25.2.1 Macronutrients
Macronutrients, the primary building blocks of our diet are found in almost every
food item. During metabolism these are processed into chemical energy which are
then converted into cellular energy for utilization by the body to perform bodily
functions (Mahan and Raymond 2016; Titchenal et al. 2018). There are three main
macronutrients: lipids, carbohydrates, and proteins.
25.2.1.1 Lipids
Lipids are chemically defined as water insoluble (lipophilic or hydrophobic) substances that are esters of fatty acids, phosphoric acid etc. They are found in eggs,
shellfish, animal fat, soya products, olive oil, milk and coconut fat (Table 25.1).
Together with carbohydrates, sterols and proteins, lipids in the form of fats and oils
are the main constituents of living cells. Fats are glycerides of predominantly saturated fatty acids and solid at room temperature, whereas oils are glycerides of unsaturated fatty acids and exist in liquid form. These are abundantly found in butter,
oils, meats, dairy products, nuts, seeds, and in many processed foods, and execute
K. Sharma et al.