Tuesday, April 28, 2020

Everything you need to know about the carbohydrates , its types, role of carbohydrates in our body and good and bad carbs.


This article tells Everything you need to know about the carbohydrates , its types, role of carbohydrates in our body and good and bad carbs.

 Let's start from here to know what is carbohydrates.

 INTRODUCTION

Carbohydrates made up of C,H,O in the ratio of  1:2:1. Atoms of carbon, hydrogen and oxygen form carbohydrate compounds such as sugar and starch.. Carbohydrates are the body’s preferred source of energy and in fact your brain needs a constant supply of carbohydrates.
“The term carbohydrates or saccharides is derived from a Greek word Sakcharon (meaning sugar) . Chemically are polyhydroxy   aldehydes or polyhydroxy ketones or substances that yield such compounds on Hydrolysis. “
Carbohydrates form a major part of calorific intake along with fats and proteins and thus are grouped under the term Macro nutrients.
Carbohydrates are the sugars, starches and fibers found in fruits, grains, vegetables, and milk products.
Apart from acting as biological fuel, also function by preserving the structural and functional integrity of the organism.
40 – 50 per cent of your daily diet to be made up of carbohydrates for good health.

What are the form of carbohydrates ?

 On the basis of number of component carbon atoms
There are five types of carbohydrate sugars, glucose, fructose, sucrose, maltose and lactose

 Monosaccharides(simple sugar)

 It contain at least three carbon atoms and represent basic unit of carbohydrates.
 examples include:
Glucose- (most abundant in nature) also called dextrose or blood sugar are as poor source. It consists of a 6- carbon atom compound.
Fructose- (fruit sugar or levulose) is the sweetest sugar, has same chemical formula as glucose but different C-H-O linkage . Some fructose moves directly from the digestive tract into the blood, but all eventually converts to glucose in the liver.
Galactose-Galactose does not exist freely in nature; rather, it combines with glucose to form milk sugar in the mammary glands of lactating animals. The body converts galactose to glucose for use in energy metabolism.

Disaccharides

Disaccharides contain two monosaccharide units covalently bond to each other, together with monosaccharides are called simple sugars.
 examples include:-
Sucrose (cane sugar/ table sugar), most abundant. It occurs naturally in most foods that contain carbohydrates, especially  cane sugar, brown sugar, sorghum, maple syrup, and honey.
Lactose (lactose or milk intolerance is basically seen in Africans an almost all Orientals due to low levels of beta-D Galactosidase or lactase enzyme) Lactose found in milk only.
 Maltose (malt sugar) occurs in beer, breakfast cereals, germinating seeds.

 Oligosaccharides

 Oligosaccharides  made up of 2 to 10 monosaccharides bond chemically  yield short chains, usually three to six monosaccharide units upon hydrolysis example- maltotriose usually occur in plants.

 Polysaccharides

Made up of more than 10 monosaccharides.
 Linkages are formed by three up to thousands of sugar molecules by the process of Dehydration Synthesis  can be:-
Homopolysaccharides- same type of monosaccharide-starch and glycogen
Heteropolysaccharides- more than one type of monosaccharide units- Hya
lorunic acid.
  •  Another way of classifying polysaccharides:
              - Plant Polysaccharides (starch and fiber)
             
 Plant Polysaccharides
 Starch storage form of carbohydrates in plants, occurs in seeds, corn, grains of bread, cereal, pasta etc., occurs in two forms:-
1. Amylose- long straight chain of glucose units twisted into helical coil.
-Animal Polysaccharides (glycogen).
 2. Amylopectin-highly branched monosaccharide linkage
* starches with higher amylopectin amounts are rapidly digested and absorber while those with higher amylose amounts hydrolyse at a slower rate.
 * The term complex carbohydrates describes dietary starch accounts for 50% of the total intake  of carbohydrates.

DIETARY FIBER 


oats is good source of complex carbs.
image from pixabay
FIBER are classified as a non starch, structural polysaccharide includes  cellulose.
 Bonds of fibers  cannot be broken down during the digestive process( minimal or no energy available).
They retain considerable water and thus give bulk to the food .
Types
  •  Water-soluble fibers viscous fermentable:- easily digested by bacteria in associated with protection against heart disease and diabetes (lower cholesterol and glucose levels) and found in legumes and fruits.
  • Water-insoluble and not easily fermentable:- promote bowel movements alleviate constipation and found in grains and vegetables.
  •   Although excessive fiber intake inhibits intestinal absorption of minerals calcium, phosphorus and iron.
  •  Daily intake of fiber is recommended as a diet that contains 20-40 g of fiber depending on age) per day (ratio of 3:1 for water insoluble to water soluble fiber.
GLYCOGEN (The Animal Polysaccharide)
Glycogen  Is the storage carbohydrate within mammalian muscle and liver
A large polysaccharide polymer from glucose by the process of Glucogenesis.
Muscle glycogen accounts for largest carbohydrate reserve.
RECOMMENDED INTAKE OF CARBOHYDRATES
• Cereals, cookies, candies, breads, cakes provide rich carbohydrate sources .
• Fruits appear to have less carbohydrate value due to high water content.
 • For more physically active people and those involved in exercise training, carbohydrate should equal about 60% of daily calories or 400-600 grams predominantly as unrefined, fiber rich fruits, grains and vegetables.
• Periods of intense training require carbohydrate intake increase up to 70% of total calories consumed.

 ROLE OF CARBOHYDRATES IN THE BODY

They serve four important functions related to exercise performance and energy metabolism.

  1. Fuel for Central Nervous System.
  2. Energy Source.
  3. Prevent ketosis.
  4. Protein Sparer.

  •   ENERGY SOURCE
    Carbohydrates as energy source. Glucose is the blood sugar,primarily serve as an energy fuel, particularly during high intensity exercise.Catabolism of blood-borne glucose and glycogen drives the process of muscle contraction and other forms of biological work.Limited glycogen storage is replenished by sufficient daily intake of carbohydrates. Once the capacity for maximal glycogen storage is surpassed, excess sugars are converted and stored as fat. The body can store about ½ day supply of glycogen for energy.

  • PROTEIN SPARER

  • Protein serves important role in tissue maintenance, repair, and growth and to a considerably lesser degree as a nutrient energy source. Adequate carbohydrate intake helps to preserve tissue protein.Depletion of glycogen stores triggers gluconeogenic activity to allow availability of carbohydrates from the labile pool of amino acids to maintain plasma glucose levels. It strains body's muscle protein and under extreme conditions adds a solute load on kidneys by forcing excretion of nitrogenous waste produced from protein breakdown.

  • PREVENTS KETOSIS

  • Components of carbohydrate catabolism serve as the "primer" substrate for fat oxidation. Insufficient carbohydrate breakdown - in case of limitations in glucose transport (Diabetes- either insulin wanes or resistance to it occurs) or glycogen depletion (inadequate diet or prolonged exercise) leads to fat mobilisation to exceed the fat oxidation. Lack of adequate by-products of glycogen catabolism produce in complete fat breakdown with accumulation of "ketone bodies"  which in excess cause body fluid acidity to rise and cause potentially harmful condition called ketosis.

  • FUEL FOR CENTRAL NERVOUS SYSTEM (CNS)
    CNS requires uninterrupted stream of carbohydrate for proper function and normally metabolizes glucose almost exclusively as its fuel source.  Brain starts metabolizing fat as fuel when :
    Blood sugar usually remains regulated within narrow limits for two main reasons:  
  • 1.     Glucose serves as a primary fuel for nerve tissue metabolism. 2. Glucose represents the sole energy source for red blood cells.

   At rest and during exercise glucose levels are maintained at 100mg/dl. through liver  glycogenosis.
In prolonged exercise, liver glycogen depletes leading to hypoglycaemia  symptoms of which include: weakness, hunger, mental confusion and dizziness.
 This impairs exercise performance leads to
CNS fatigue. This on prolongation triggers unconsciousness and irreversible brain damage.
A carbohydrate-deficient diet rapidly depletes muscle and liver glycogen and negatively affects performance in short-term anaerobic exercise and prolonged intense aerobic activities.

      What are good carbs?

  The following lists of good carbs are recommended for a healthy diet.
whole wheat bread image from pixabay
    
  •                 Vegetables – eat a variety of vegetables every day.
  •          Nuts and seeds.
  •                Beans and legumes.
  •          Tubers –sweet potatoes.
  •                 Whole grains- such as oats, quinoa, brown rice, whole wheat bread, cereals and barley.
  •          Whole fruits.

What are bad carbs ?

The following lists of bad carbs are associated with health problems such as diabetes and obesity.
  •        Refined grain bread, white rice and grains.
  •      Refined carbs are not healthy, these include carbonated drinks.
  •       Junk foods, pastries.
  •      Pasta ,beer, sugary products.
  •      Starchy vegetables.

Click here to know everything about carbohydrates - https://www.okhealthok.com/2020/04/everything-you-need-to-about.html

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