Wednesday, February 25, 2009

Obesity

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Obesity
Obesity is affecting adults and children in the world.
BMI = weight(kg) / height (m2)
BMI of 30 or greater is categorized under obese.
Food consumption in developing and industrialized countries is increasing every year.

Causes of Obesity
1. Overeating
2. Sedentary lifestyle
3. Physiological factor
4. Genetic
5. Smoking
6. Medication and drug
7. Environment factor: fast food, busy lifestyle, video gaming

Problems Associated with Obesity
1. Respiratory problems
2. Heartburn
3. Menstrual irregularity
4. Sleep apnea
5. Depression
6. Cardiovascular diseases
7. Muscle skeletal problems
8. Venous stasis disease
9. Loss of urine control
10. Infertility

Prevention of Obesity
1. Choose healthy food
2. Prevent overeating
3. Reduce alcohol intake
4. Regular exercise
5. Take Balance and variety meal
6. Minimize fat in meal preparation
7. Reduce sugar intake such
8. Maintain healthy body weight
9. Practice good eating habit since childhood
10. Promote breast feeding

Monday, February 16, 2009

Curry Laksa


Curry laksa is one of locals’ favourite foods. It is quite similar to curry chicken mee. However, there are some differences between curry laksa and curry chicken mee. Curry chicken mee contains only chicken and noodles whereas curry laksa contains more ingredients such as bean sprouts, fried bean curd cubes (taufu-pok), chickens, long beans, cockles as well as optional types of noodles. Moreover, the amount of coconut milk used in cooking curry laksa is more compared to curry chicken mee.

Metabolism Involved
The main sources of carbohydrates come from noodles. Carbohydrates can provide energy after digestion and absorption. The digestion starts in the mouth where the starch is broken down to smaller units by saliva containing enzyme amylase. Carbohydrates pass through the stomach and into the small intestine. Most digestion and absorption occurs in small intestine where digestive enzymes are secreted from the pancreas and small intestine to breakdown starch into smaller units. Pancreatic amylase (from pancreas) breaks starch into disaccharides and small polysaccharides whereas enzymes from small intestine break the remaining disaccharides into monosaccharide components. Sugars such as galactose, glucose, and fructose that are produced by the breakdown of polysaccharides enter into absorptive intestinal cells. After absorption, they are transported to the liver where galactose and fructose are converted to glucose and released into the bloodstream. Glucose is able to produce energy for the body through a series of processes. Glucose undergoes glycolysis, Krebs cycle and electron transport system to produce ATP (activated carrier which gives organisms energy). The glucose may be sent directly to organs that need energy, it may convert into glycogen (in a process called glycogenesis) for storage in the liver or muscles, or store as fat in adipose tissue.




Figure 1: Metabolism of carbohydrates (UNISA, 2008)

In addition, curry laksa also provides protein source which mainly come from chicken as well as fried bean curd (taufu-pok). Protein breaks down into amino acids by digestion. Initial physical breakdown of protein begins in the mouth. Then, the stomach secretes pepsinogen which will then convert into pepsin. Pepsin helps in breaking protein into amino acids. Once the food moves into duodenum, duodenum and pancreas work together to breakdown protein into single amino acid molecules with the help of trypsin. Amino acid molecules absorb into the small intestine and pass into the bloodstream. The amino acids are then carried by blood to the body in order to rearrange into human proteins as well as use in building its structure. Excess amino acids will be metabolized to glycogen or fat and used for energy metabolism. Amino acids will be used to produce energy when starvation. The carbon skeletons are converted to acetyl CoA, which enters the Krebs cycle for oxidation to produce ATP.

Furthermore, noodles and fried bean curd (taufu-pok) contribute most fats in curry laksa. Digestion of fats starts in the small intestine with the aid of lipases and bile acids where fats breakdown into smaller units. The smaller units are absorbed through the wall of the intestine then they are reassembled into triglycerides and carried into the body through the lymph system on chylomicrons. Lipid can metabolize through several pathways such as lipolysis, betaoxidation, ketosis, and lipogenesis. Lipolysis (fat breakdown) and beta-oxidation occurs in the mitochondria. It is a cyclical process in which two carbons are removed from the fatty acid per cycle in the form of acetyl CoA, which proceeds through the Krebs cycle to produce ATP (Patel, 2008). The rate of formation of ketones by the liver is greater than the ability of tissues to oxidize them, ketosis occurs. This happens when large amounts of fats are consumed in the absence of carbohydrate or during prolonged starvation. Lipogenesis is the process by which glucose is converted to fatty acids, which are subsequently esterified to glycerol to form the triacylglycerols that are packaged in VLDL and secreted from the liver (Wikipedia_Lipogenesis, 2009). Lipogenesis encompasses the processes of fatty acid synthesis and triglyceride synthesis (Wikipedia_Lipogenesis, 2009).

Figure 2: Catabolic processes of proteins, carbohydrates and fats (Hardy, 2005)

Nutritional Value and Benefits of the Ingredients of Curry Laksa:

The main ingredient for curry laksa, chicken especially chicken breast is a very good source of protein. Protein helps in growth of bone, acts as enzymes, hormones, regulators of fluid balance, acid-base regulators and transport proteins, defend the body against disease by producing antibodies as well as source of energy. In addition, chicken also contains the cancer-protective B vitamin, niacin. Niacin is important in components of DNA. Deficiency of niacin as well as other B-complex vitamins leads to genetic (DNA) damage (Mateljan, 2007). Trace mineral, selenium also can be found in chicken. It is an essential component of several major metabolic pathways, including thyroid hormone metabolism, antioxidant defense systems, and immune function (Mateljan, 2007).

Cockles in the curry laksa have a high content of selenium, vitamin B12, iodine and iron. Selenium is an antioxidant and helps to regenerate vitamins E and C so that they can fight with free radicals (Obikoya, 2009). Besides that, iron also helps to promote growth of red blood cells.

Other than cockles, long beans in the curry laksa are high in fiber, vitamins and minerals as well as low in fat and calories. It provides a good source of protein, vitamin A, thiamin, riboflavin, iron, phosphorus, and potassium, and a very good source for vitamin C, folate, magnesium, and manganese (Wikipedia_ Yardlong bean, 2009). Fiber helps to reduce the glycemic effect of meals and contributes to colon health. Moreover, it seems to help in lower the cholesterol and triglycerides level and also may help to prevent ulcers, particularly in the beginning of the small intestine (duodenal ulcers), diabetes, heart disease and colorectal cancer (Dolson, 2007). Besides that, fiber also helps in management of constipation, increasing the stool output and also beneficial for irritable bowel syndrome.

Bean sprouts in curry laksa contain significant amount of proteins, vitamin C and number of essential B vitamins which are needed by body for proper functioning of various body system (Ayushveda, 2008). Bean sprouts forms the ideal food for those who go on for dieting as it is very low in calories and be eaten without putting any dressing.


Recommended Nutrient Intake (RNI) of Curry Laksa:


1 bowl of curry laksa contains approximately:


Ø 41% of total energy required daily
Ø 17% of carbohydrate required daily
Ø 84% of protein required daily
Ø 67% of fat required daily


As we are taking 3 meals in a day, energy and nutrients required from a bowl of curry laksa should only fulfill 1/3 of daily diet. This means that, a bowl of curry laksa should only contain approximately 33% of energy and nutrients required daily. However, we can see that the total energy, protein and fat contents in a bowl of curry laksa that we usually eat are higher than what we require whereas carbohydrate is lower than what we require.

In this case, curry laksa can be modified to enable us to have maximum benefits of it and at the same time reducing the adverse effects of it. First, we can use white soya bean curd (white taufu) instead of fried soya bean cubes (taufu-pok). As taufu-pok is very high in fat, it provides too much energy that it raise the calories (energy) contain in curry laksa highly. So, using white taufu instead of taufu-pok can lower the fat content in curry laksa, therefore reducing the calories in curry laksa. White taufu contains no cholesterol and is very low in fats. It contains proteins, carbohydrates, polyunsaturated fatty acids, various minerals and vitamins, nutrients that are easily absorbed by the human bodies. Second, we can choose to use rice noodles rather than other types of noodles as it is high in carbohydrate but low in fat. Long beans, fried soya bean cubes, chicken and bean sprout are all high protein food, so, by decreasing the amount of some of these food, the protein contents in curry laksa can be lowered. Therefore, the amount of chicken and white taufu replacing taufu-pok is decreased to obtain lower content of protein in curry laksa. The amount of long beans, cockles and bean sprouts are not modified because they contribute least in nutrients of the curry laksa as they are used in small amount. However, we need to make sure that the cockles are fully cooked before they are eaten because it may cause Hepatitis A. Lastly, not to leave out fruits in a meal, banana will be good to balance out the modified curry laksa.


Recommended Nutrient Intake (RNI) of Modified Curry Laksa:



1 bowl of modified curry laksa and banana contains approximately:


Ø 28% of total energy required daily
Ø 30% of carbohydrate required daily
Ø 32% of protein required daily
Ø 14% of fat required daily

Written by,

Elsie & Cheng Siew

References:
Ayushveda, 2008. Health Benefits of Bean Sprouts [Online]. Available from:
<
http://www.ayushveda.com/womens-magazine/health-benefits-of-bean-sprouts/> [Accessed on 7 February 2009]

Dolson, L., 2007. Fiber [Online] Available from:
<
http://www.vitamins-nutrition.org/vitamins/selenium.html> [Accessed on 7 February 2009]

Hardy, J.K., 2005. Carbohydrate Metabolism [Online]. Available from:
<
http://ull.chemistry.uakron.edu/genobc/Chapter_23/> [Accessed on 7 February 2009]

Mateljan, G., 2007.Chicken [Online]. Available from:
<
http://www.whfoods.com/genpage.php?tname=foodspice&dbid=116> [Accessed on 7 February 2009]

NutriWeb Malaysia, 2009. Malaysian Food Composition Database [Online]. Available from:
<
http://www.nutriweb.org.my/searchfood.php?submit_search=Back+to+Search>[Accessed on 14 February 2009]

Obikoya, G., 2009. The Benefits of Selenium [Online]. Available from:
<
http://www.vitamins-nutrition.org/vitamins/selenium.html> [Accessed on 7 February 2009]

Patel, G., 2008. Metabolism [Online]. Available from:
<
http://www.faqs.org/nutrition/Met-Obe/Metabolism.html>[Accessed on 7 February 2009]

Wikipedia_Lipogenesis, 2009. Lipogenesis [Online]. Available from:
<
http://en.wikipedia.org/wiki/Lipogenesis> [Accessed on 7 February 2009]

Wikipedia_ Yardlong bean, 2009. Yardlong bean [Online]. Available from:
<
http://en.wikipedia.org/wiki/Yardlong_bean> [Accessed on 7 February 2009]

UNISA, 2008. Carbohydrate Metabolism [Online]. Available from:
<
http://www.unisanet.unisa.edu.au/08366/h&p2carb.htm> [Accessed on 7 February 2009]

United States Department of Agriculture, 2009. Nutrient Data Laboratory [Online]. Available from:
<
http://www.nal.usda.gov/fnic/foodcomp/search/>[Accessed on 14 February 2009]