Understanding the digestive process helps us understand the need for good food habits, and the need to eat at the proper times.

1. Digestion in the Mouth

As you chew food in your mouth, the food is broken into smaller pieces and mixed with saliva. Saliva contains an enzyme—salivary amylase or ptyalin—that changes the insoluble starches into simpler soluble forms. For effective digestion, keep the following points in mind. 

  • Chew the food properly. This will break it down into smaller pieces, increasing the surface area and contact with the saliva. 
  • Avoid very sour items (sour curds, lime, etc.) in combination with rice and chapatis. The acids in sour foods will not permit digestion in the mouth, as saliva needs an alkaline medium to work. This is especially true for people with poor digestion, who experience belching and sour liquids in the mouth after meals. 
  • Avoid pasty or watery foods. One tends to just swallow them, leading to poor salivary digestion. Follow the dictum—“Drink the solids, eat the liquids.”

2. Digestion in the Stomach 

The stomach is a living bag, continuously contracting and expanding so that food in it gets thoroughly churned up. While food stays in the mouth only for a few seconds, it spends more time in the stomach, between two to three hours. The digestion of proteins commences in the stomach, to be finally completed in the intestines along with carbohydrates and fats.

In the digestive process, the stomach secretes pepsin, which breaks down the long protein chains into smaller units, called peptones that are soluble in water. It also secretes Hydrochloric Acid, which does many important jobs in the stomach. It provides the acidic medium in which pepsin can work. It also kills bacteria that enter the stomach with the food.

3. Digestion in the Small Intestine

The third phase in digestion takes place in the small intestine, a very long tubular structure, about 5 or 6 times the body height, 20 feet in length, cleverly folded up and tucked into the abdomen behind the navel region. The pancreas and the gall bladder pour out their digestive enzymes at the beginning of the small intestine. These enzyme rich juices digest the semi-digested proteins, starches, and sugars. Fats are digested into simpler substances with the help of enzymes. The bile secreted by the gall bladder converts simple fats into globules.

Finally the simpler units of proteins, fats, and carbohydrates are absorbed into the bloodstream, across the lining of the small intestine. The vitamins and minerals are also simply absorbed into the blood. In normal healthy state, it takes 4 to 6 hours for food to pass through the small intestine.

4. Digestion in the Large Intestine

It follows the small intestine. It looks like a bicycle tube and goes around the abdomen like the letter U placed upside down. As digested food passes along the large intestine, water gets absorbed along with the vitamins and minerals. The food remains become harder and finally reach the outlet called anus and pass out as stools.

5. Acidity

When a log of wood is burnt, it leaves behind some ash. When any food is digested, absorbed and metabolized (burnt up), it also leaves some residue in the cells of the body. This can be acidic or alkaline. This is measured on pH scale from 1 to 14, in which 7 is the neutral value. The pH value of our blood is 7.4 alkaline. Optimal health is in a mildly alkaline body. All the fluids in the body, with the exception of the stomach, are or should be alkaline.

The average 21st century lifestyle, diet, and environment produce far more acid in the body than is necessary. 90% of the population is too acidic. The results of this are:

  • Connective tissues are weakned and facial skin and hair lose their tone.
  • Sleep pattern gets disturbed. Relaxing deep sleep is reduced.
  • Physical and mental exhaustion by mid-afternoon.
  • Colds infections, headache, and flu are common.
  • Friendly bacterial in the intestines die and the immune system gets impaired.
  • Vitamins and minerals from food are not absorbed well.
  • Free radical oxidation occurs with great ease.
  • Digestion is impaired and flatulence and bloating is more frequent.

Thus, the number of calories we consume means nothing unless they come from proper food. We must consume both—alkali and acidic ash foods—daily, since both are necessary. In general, fruits and vegetables yield an alkali ash, whereas meat, milk products, oils, nuts, etc. yield an acidic ash. Grains yield an acidic ash. Pulses and beans yield an acidic ash, but when sprouted they yield on alkali ash. Coffee, alcohol, tobacco, sauces, vinegar yield an acidic ash. Honey, ginger, herbal teas yield an alkali ash. We should eat a diet that is 75 per cent alkali ashes formation and 25 per cent acidic ashes. Our present day diet is the reverse of this.

To maintain the proper proportion between acidic and alkali ash in the body, follow the general guidelines: 

  • Eat some fresh fruit every day and include salads in each meal. 
  • Include fresh sprouts in your diet, either raw or conservatively cooked. 
  • Substitute in-between snacks with fresh fruits and nuts. 
  • Develop the habit of enjoying freshly squeezed lime in one glass of water daily, a minimum of one lime a day. Lime and other citrus fruits taste acidic and are acidic for the first hour in the body, but leave an alkaline effect on the body after being assimilated. 
  • Minimize fried foods, packaged foods, processed, and stale foods. Eat freshly cooked food, do not cook and store in the refrigerator. 
  • Reduce consumption of pasteurized milk products. 
  • Calm the mind through Yog, music, prayer, etc. React to others with love and compassion. Moderate exercise, walking in fresh air, Yogic stretches, and pranayam are all conducive to reducing the acidic ash formation in the body.


  1. Sushree 09/07/2022 at 3:52 pm - Reply

    Very useful facts. Thanks for this wonderful post .

  2. Manjushree Nanda 24/07/2022 at 10:19 pm - Reply

    Thanks for the useful article.

  3. Liza Panigrahy 26/07/2022 at 7:03 pm - Reply

    Wow! I just wonder to know all of the science behind the digestion of the Food we eat in our body and all over the Digestive system!! This is really such so sensitive and longer journey to digest food in our body!! So we must have aware of our food what we have taken carefully and to having in proper way to stay healthy! So so amazing Article!! Thank lots!!

  4. MANORAMA DAS 27/07/2022 at 11:16 am - Reply

    So important and interesting article science behind digestive system. Thank you so much.

  5. Aryan Raj 04/08/2022 at 11:56 am - Reply

    Very amazing and basic practices are taught in this health Blog. Chewing food, physically active lifestyle, mental happiness, etc are really helpful for a good health.

    • Sailendra narayan Das 14/01/2023 at 11:00 am - Reply

      Nice information . Thank you for sharing.

  6. MANORAMA DAS 11/01/2023 at 7:35 pm - Reply

    So useful and practical information. Thank You.

  7. K Pragati 13/01/2023 at 2:25 pm - Reply

    Thanks for this useful information. Radhey Radhey

  8. Sudhanalini sarangi 13/01/2023 at 7:25 pm - Reply

    Very useful tips. Thanks JKyog team

  9. Praful Thapliyal 13/01/2023 at 9:29 pm - Reply

    Wow! I have been searching for healthy diet for long, and came across this beautiful gem of knowledge regarding health and diet, it’s amazing, thank you team for beautiful content

  10. Santosh Kumar Mahanty 16/01/2023 at 12:41 pm - Reply

    Very use full tips

  11. Santosh Kumar Mahanty 16/01/2023 at 12:42 pm - Reply

    Very nice

  12. Santosh Kumar Mahanty 16/01/2023 at 12:43 pm - Reply

    Beautiful tips

  13. Manjushree Nanda 17/01/2023 at 2:38 pm - Reply

    We must go through the article to stay healthy.Thank you.

  14. VIKAS 18/01/2023 at 9:55 am - Reply

    This article is very helpful, thanknyou

  15. Sudhanalini sarangi 30/01/2023 at 7:57 pm - Reply

    Very informative facts, I ever know. Also useful for systematic life style.

Leave A Comment