Carbohydrates: Types, Source, Benefits, Risks


Carbohydrate is the amplest biomolecule found in living organisms as well as a significant macronutrient of our daily food intake. 

  1. What is Carbohydrate?
  2. Types of Carbohydrates
  3. Rich Sources of Carbohydrates
  4. How much carbohydrate do we need daily?
  5. What is Dietary fiber?
  6. Why Cellulose is important for health?
  7. Functions of carbohydrates
  8. Carbohydrates Deficiency Syndromes
  9. Impact of Excessive Carbohydrates on Health

1. What is Carbohydrate?

Chemically, carbohydrate is a compound of carbon, hydrogen, and oxygen. It is a polyhydroxylated aldehyde or ketone
Carbohydrate provides energy to organisms and it is the primary source of energy for all living beings on the earth. 
There are mainly three types of carbohydrates that we consume in food. Namely starch, sugars, and cellulose.
General Formula - (C6H12O6)

1 medium cookie = 7 g of carbohydrates

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2. Types of Carbohydrates:- 

Carbohydrates can be divided into four types -

i) Monosaccharides 

Monosaccharides are the most lucid form of carbohydrates which means it cannot be hydrolyzed to smaller carbohydrates. The general formula of monosaccharide is (CH2O)n.

Some examples of monosaccharides are - 
  • Triose e.g. Glyceradehyde
  • Tetrose e.g. Erathrose
  • Hexose e.g. Glucose, fructose, and galactose

ii) Disaccharides 

These are made up of two monosaccharide molecules. The general formula for disaccharides is (C12H22O11). Some examples of disaccharides are -
  • Sucrose: Sucrose means normal sugar. It's available in sugarcane, beetroot, and in some fruits and veggies.
  • Maltose: During germination, starch gets converted into maltose due to the enzyme called Amylase. 
  • Lactose: It is found in milk.

iii) Oligosaccharides

They yield 2 to 10 monosaccharide molecules upon hydrolysis. Disaccharides are oligosaccharides too. Examples of oligosaccharides -
  • Trisaccharide - Raffinose, found in beet.
  • Tetrasaccharide - Scorodose, found in onion and garlic.

iv) Polysaccharides

These are a combination of more than 10 monosaccharides. These are generally insoluble in water and extracted from plants. The general formula is (C6H12O5)n. Some examples of oligosaccharides are -
  • Starch - It's found in plants.
  • Dextrin - It's found in toasted bread, yeast, and some bacterias.
  • Glycogen - It's found in the liver and muscles of the human body, fungi, and yeast.

According to reducing power, there are two types of Carbohydrates -

i) Reducing sugar - Carbohydrates that act as a reducing agent because of the presence of a free aldehyde (-CHO) or ketone(-CO) group are known as reducing sugar.
Example - Glucose, fructose, galactose, lactose, maltose, and dextrin.

ii) Non-reducing sugar - Carbohydrates which don't have free aldehyde(-CHO) or ketone(-CO) is called non-reducing sugar.
Example - Sucrose. Almost all polysaccharides are non-reducing sugar.


3. Rich Sources of Carbohydrates

  • Cereals: Wheat, Rice, Maize, Bajra, Jowar, Ragi, Barley, Quinoa, Oats
  • Roots and Tubers: Sweet Potato, Tapioca, Potato,
  • Fruits: Apple, Mango, Bananas, Blueberries, Oranges, Grapes, Dates, Raisins
  • Pulses: 36 to 60% carbohydrates available in various pulses.
  • Nuts: 3.9% carbohydrates available in nuts.
  • Green Leafy Vegetables: Full of cellulose.

Sugarcane, honey, jaggery, milk, fruits, and beetroots are sources of sugar, and the cell walls of fruits, vegetables, and cereals are sources of cellulose.

Starch and sugars get absorbed into the human body as glucose. The surplus glucose is changed into glycogen which is stored in the liver for subsequent use.

Presence of particular types of carbohydrates :
  • Glucose: 2 to 6% in various fruits and 30 to 40% in honey.
  • Fructose: 2 to 5% in some fruits along with glucose and 30 to 40% in honey as a free element.
  • Sucrose: 10 to 12% in sugarcane juice and 12 to 18% in beetroot sugar.
  • Lactose: Milk and milk products.


4. How much carbohydrate do we need daily?

A normal person needs about 400 to 500 grams of carbohydrates daily in the diet. But when it comes to a growing child or a person who does hard physical work or something like that, their energy requirement is much higher than normal people.

An adult woman needs 1600 to 2400 calories and an adult man needs 2000 to 3000 calories daily. So, an adult needs 2000 calories overall per day. 

According to American dietary guidelines, carbohydrate provides 45 to 65% of our daily calorie intake. Which means 900 to 1300 calories should be provided by carbohydrate. 

1 g carbohydrate can produce 4 Kcal energy. Saying more clearly we need 225 to 325 grams of carbohydrate per day.

5. What is dietary fiber?

Dietary fiber is a very significant polysaccharide. Dietary fibers are indigestible. Enzymes that help to digest don't work on fibers. According to solubility, there are two types of fibers - soluble and insoluble in water.
Insoluble fibers are lignin, cellulose, and hemicellulose. Pectin, gam, and mucilage are noticeable among soluble fibers.

6. Why Cellulose is important for health? 

Cellulose is the most essential fiber we get from food. It's an animal starch. Cellulose gives our food a volume and satisfy our hunger but don't get absorbed into the body as we lack cellulose digesting enzyme.

The presence of cellulose in food controls the amount of glucose in the blood. And enhance glucose tolerance power in diabetes patients.

Cellulose controls the amount of cholesterol in the blood by preventing cholesterol absorption and also lessens the amount of fat.

But that's not all. Various nutritionists have shown that the amount of cellulose we are consuming actually matters in various ways.

Deficiency of Cellulose in Food :

  • Too less amount of cellulose in food can promote Ischemic heart disease, Diabetes, Diverticular Disease, and Colon Cancer.

Risks of Excessive Cellulose in Food :

  • The abundance of cellulose disturbs the digestion of protein. Protein fails to digest. 
  • It lessens the absorption of calcium, magnesium, and phosphorus.
  • An adult should consume 4 to 7 grams of cellulose daily.

Average Amount of fiber in various foods :

  • Cereals and pulses - 2.3%
  • Green leafy vegetables - 1.2%
  • Tubers and roots - 0.8%
  • Other vegetables - 1.9%
  • Nuts - 3.9%
  • Fruits - 2.2%


7. Functions of Carbohydrates

Essential functions that make carbohydrate important are as follows - 

i) The Main Source of Energy :

Carbohydrate is the nutrient from where we get the most of our required energy. We get 4 Kcal energy from 1 g of carbohydrate. Body gain direct energy from the digestion of carbohydrate for metabolism and unused energy is stored in the form of glycogen in the body and whenever needed it gets consumed accordingly.

ii) Protein Sparing Action :

When carbohydrates are absent in our meal then stored protein is consumed by the body as the energy source. Proteins are necessary for the synthesis of enzymes, antibodies, etc so adequate intake of carbohydrates prevents the degradation of skeletal muscles and other tissues like kidney, liver, and heart hence ketosis prevented.

iii) Necessary for Fat Oxidation :

Our body needs carbohydrates to burn fats. Carbohydrates break down into oxaloacetic acid. It is necessary to metabolize fats, without this break-down, fats get converted into ketones, which is highly toxic to our body.

iv) Provide Sweetness for Food :

Carbohydrates provide sweetness to the food. Taste receptors of the tongue bind with tiny beats of carbohydrates and send taste signals to our brain. This sweetness keeps changing such as - fructose is almost twice as sweet as sucrose and sucrose is almost 30% sweeter than glucose.

v) Control Various Physiological works :

Glucose plays a great role in controlling body temperature, muscle contraction and relaxation, functions of nerves, the temperature of blood, and many other important bodily work. 

vi) Dietary Fiber :

The cellulose we get from leafy vegetables not only gives our food an extra volume but also take proper care of our intestinal health. 


vii) Absorption of Minerals :

Minerals are very much important for the human body. Carbohydrate helps to get absorbed the minerals from food into our body.

8.Carbohydrate Deficiency Syndromes:

  • Tiredness is the most important syndrome of carbohydrate deficiency. Carbs are the main source of energy for the human body. Long term fatigue is the thing you get when your food is lacking carbs on a daily basis.
  • Deficiency of sugar in the blood cause hypoglycemia including symptoms like dizziness, shakiness, hunger, weakness, anxiety, etc.
  • Among all the nutrients fat produces the highest amount of energy but this process of producing energy from fats remains incomplete in the absence of carbohydrates. 
  • And this incomplete burning of fat can create ketone bodies which can cause a disease name Ketosis
  • As a symptom of ketosis, there can be mental fatigue, nausea, headache, bad breath, swelling in joints, and kidney stones in case of severe ketosis.
  • Lacking carbohydrates in food can be a reason for constipation.

9. Impact of Excessive Carbohydrates on Health:

  • Too much consumption of carbohydrates raises the sugar level in the blood which can lead to Diabetes.
  • Having too much food containing sugar can lead to obesity.
  • Adding more dietary fibers to our food list can help in losing weight. Green leafy vegetables play a very significant role in a low-carb diet as they fulfill hunger but don't trigger weight gaining

Conclusion :

That's all for today guys. I hope this will help you decide whether you are on a good term with carbohydrates or maybe you need to do some modification with it.

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Thank you for visiting and reading.
Love and care from Anny's Pen.
See you in the next blog.

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  1. Thank you for every information gained about carbohydrates .