Days Menu and the Digestive Process - Essay Example

Below are the menus for a day where the recommended daily allowance of calories is 2,200. Other recommended allowances are 285g of carbohydrates, 55g of fat, and 44g of protein. 

BREAKFAST MENU

2 fried eggs (2 servings)

1 cup milk (1 serving of 250ml)

Vegetable Sandwich (2 servings of bread and ½ serving of vegetables)

1 medium size apple (1 serving)  

Total Calories- 626 (68g carbohydrates, 20.9g fat, 17.4g proteins)

LUNCH MENU

1 cup beef stew (1 serving)

2 cups long-grain boiled rice (2 servings)

1 cup steamed broccoli (1 serving)

Total Calories-615 (101g carbohydrates, 9.6g fat, 11.2g protein)

SNACK

1 regular hotdog (1 serving)

1 cup of freshly squeezed orange juice (250ml)

Total Calories-354 (44g carbohydrates, 15g fat, 6.3g protein)

DINNER MENU

1 tender roasted chicken breast (1 serving)

2 cups macaroni and cheese (2 servings)

½ cup vegetable salad (0.5 serving)

Total Calories- 616 (87.4g carbohydrates, 13.3g fat, 12.2g protein)

Total Calories for the day- 2,211 (300.4g carbohydrates, 58.8g fat, 47.1g protein)

PART B- THE PROCESS OF DIGESTION

          After having lunch (stewed beef, boiled rice, and steamed broccoli), the absorption of nutrients by the body happens as detailed below; The esophagus is a tube made of strong muscles that connect the mouth and the stomach. The bolus goes down to the stomach through it using peristaltic waves. The esophageal sphincter at its lower end makes the food stay in the stomach (Brown, 2011).

In the stomach, the chewed food is stored for a while to allow the body to digest it properly. The food is mixed with gastric acid which contains hydrochloric acid and sodium chloride. Hydrochloric acid destroys any bacteria that may have been ingested together with the food. Gastrin is the hormone that arouses the G cells to produce gastric acid. The acid then stimulates the conversion of pepsinogen to pepsin that digests proteins. To avoid the corrosion of the stomach, there is a lining of mucus around it. As the food continues being mixed to form a thick liquid called chyme, the enzyme gastric lipase starts the chemical breakdown of fat globules in the food though not completely. The glycoprotein known as an intrinsic factor is produced by the parietal cells to help in the absorption of vitamin B12. Food components that are in their simplest form like glucose are absorbed in the stomach. The peristaltic movements of the stomach then push the food down to the small intestines. The food is blocked from re-entering the stomach by the pyloric sphincter (Brown, 2011).

The small intestines are the lower part of the alimentary canal where most nutrient absorption takes place. The duodenum makes the initial phase of the small intestines where the acidic chime is made alkaline through the action of bile from the gall bladder; bicarbonates from the Brunner’s glands and bicarbonates from the pancreas. Bile that is produced by the liver is stored in the gall bladder. The enzyme pancreatic lipase further breaks down the fat molecules called chylomicrons. The pancreatic juice also digests carbohydrates to glucose and proteins to amino acids. The lining of the stomach has many small protrusions called villi that increase the surface area for the digestion of the chyme and its absorption. The emulsified fat passes through the enterocyte villi into the lymph capillaries called lacteals with the help of bile after which the lymphatic system distributes it throughout the body (Brown, 2011).

The Themidsectionn of the small intestine is called the jejunum. Here, the carbohydrates that are broken down to glucose are absorbed as well as the fatty acids and amino acids. In the third section, the ileum, the bile acids, residue nutrients, and vitamin B12 are absorbed. The chyme is then pushed to the caecum which connects to the large intestine. The large intestines contain the gut flora that helps in the fermentation of fiber and residual matter. A few nutrients including the B vitamins and Vitamin K are absorbed in addition to water. The residue remains in the large intestines for 12 to 50 hours until it is excreted from the body as feces (Brown, 2011).