Bridge

This Newsletter aims to promote communication between schools and the Student Health Service of the Department of Health

March 2014 Issue No.62

Published by the Student Health Service, Department of Health


Editiorial

"Weight loss" has becomes our catchphrase nowadays. Some people may not need to lose weight but they often think they should lose weight.

Whereas, some people should lose weight but very often do not take any action.

Do you think that you need to lose weight? How much do you know about it?
Do you have confidence in a successful weight loss progarmme if you really need to?

In this issue, we shall introduce healthy way towards weight loss by some case illustrations. We hope that readers can lose weight correctly with better health and more confidence.


KEEP FIT FORMULAE

Department of Health, Student Health Service

Dietitian: Cheung Wing Sum, Chan Ying Ying


Introduction

“Keep Fit” becomes a hot topic nowadays. Many teenagers envy models with thin body figures and try to imitate them. There are various keep fit tips available on the media and the internet. Although there is a lot of detailed programme, it may not be credible. Before starting on a weight reduction programme, you are encouraged to consider the following points:

  1. (1) Do I need to lose weight?
  2. (2) How many pounds to lose?
  3. (3) How to do it?

Proper weight reduction can help you to improve health and increase self-esteem, but on the other hand, if we lose weight in a wrong way, we would not get the expected result, but also have a bad impact on our health. Now let us learn some healthy keep fit tips through the following case.


It will soon be the graduation dinner, everyone in class is looking forward to it and thinking how they can have a good memory on that day. Winnie and Grace are worried on what to wear for the dinner as they both think that they are overweight and will not fit in any pretty dress. Today, Winnie and Grace are seeking some advice from Winnie’s sister, a dietitian.

Winnie: Sister, please help me! The graduation dinner is coming next week, I want to be slim as quick as possible, please let me know how to lose 10 pounds in a week.
Sister: Wait a minute, Winnie. You are 16 years old. You should check with the weight for height growth chart to determine whether you are overweight and if so how many pounds you should lose. Furthermore, losing 10 pounds in a week is not practical at all. Even for an adult, healthy weight loss should be 1 to 2 pounds per week only. Okay, please tell me your height and weight first.
Winnie: My height is 157 cm and my weight is 58 kg. This is top secret, don’t tell anybody! Could you please also check for my friend, Grace?
Grace: My height is 169 cm and my weight is 60 kg. Thanks a lot.
Sister: Winnie, you have gained weight recently! According to the weight for height growth chart, you are 1.8 kg overweight. For Grace, since your height is more than 165 cm, you should use the BMI (Body Mass Index) to calculate your desirable body weight. BMI means weight (kg) over height (m)², and if the index falls between 18.5 and 22.9, that means your body weight is within the desirable range. Now, Grace’s BMI is 20, so you are fine and do not need to reduce your weight.
Winnie: Sister, I want to lose weight, please tell me how to do so, I will follow your advice!
Sister: In fact, to lose weight is very simple, just follow a formulae!
Winnie: Does it mean a weight loss menu? I want it!
Sister: No! It’s all about energy balance! When energy expenditure is more than energy intake, then we lose weight.
Winnie: I see, then I shall skip my breakfast in the coming week and I will become slim.
Grace: Winnie, I guess you won’t bear the hunger. It may be even worse if you overeat at lunch when you feel hungry.
Sister: Grace is right! Skipping breakfast is not a proper way to lose weight. If we starve ourselves, our Basal Metabolic Rate (how fast our body spend the energy) would be reduced automatically and this actually facilitate fat accumulation. Therefore, Winnie, your weight could increase sharply if you starve for the whole morning and then just overeat at lunch!
Winnie: My best friend told me that not eating rice or starchy food could lose weight. Is it true?
Sister: This method is wrong! Most food items contain energy. If our energy intake exceeded our body needs, our body would transform the extra energy as fat for storage. Starchy food contains carbohydrates, which is a major source of energy and carbohydrates contain 50% less energy when compared with fat. If we consumed rice or starchy foods in appropriate amount, and chose those with higher fibre and low fat content, this would not contribute to weight gain. Furthermore, let’s think, if we have less rice/starchy food, we might have larger portions in our main dishes, which was mostly meat and cooked with oil. Larger main dish portions will therefore increase the fat intake. Winnie, if you do not eat rice but more junk snacks, it is even more difficult for you to control weight.
Winnie: Then, what should I eat in order to lose weight?
Sister: Have you heard about the healthy food pyramid?
Grace: Yes, I remember we have learnt it from the home economic lesson. Healthy food pyramid is divided into four levels, the bottom of the pyramid is the group for grains and cereals, which are the major energy source and we should eat the most. The next level up is the group for vegetables and fruits. They provide plenty of vitamins, minerals and dietary fibre, which we should eat more. The groups above that are meat and dairy products. They are rich in protein and calcium respectively, we should eat these in moderate amount. Finally, the top part of the pyramid is…...
Winnie: Let me continue. At the top of the healthy food pyramid is the group that we should eat the least, which is fat, salt and sugar.
Sister: Well done! So I suggest you to eat less junk foods including instant noodle, potato chips, sausage, luncheon meat, soft drinks, chocolate, etc., as these junks are high in fat and sugar. One pack of instant noodle contains about 470 kcal, which is about the energy content of nearly two bowls of rice!
Winnie: But… what if I cannot stand the hunger?
Grace: Winnie is always hungry, she cannot eat less!
Sister: I know you well little sister. Firstly, we should space out our 3 main meals evenly during the day, and keep meal times regular and the amount of food intake constant. You can have some healthy snacks (eg. cherry tomato, corn on the cob, skim/low-fat milk) in-between the main meals. You should read the food labels if you choose pre-packaged food. Always remember snack portions should be small and not to affect the appetite at main meals, over-eating snacks can increase body weight!
Winnie: Ok, I got it. But how come I am still hungry after taking a large bowl of rice, a bowl of meat, a bowl of soup and a little vegetables at dinner?
Sister: I know the reason, tell me how long did you take to finish your meal.
Grace: I know! Winnie eats very fast, she can finish a bowl of noodles within 5 minutes.
Sister: You should eat slowly, chew more before you swallow. You can cut the food into smaller pieces before you eat, and you can eat more vegetables. These few tips can help you to have better satiety. By the way, taking a bowl of meats is too much for you.
Winnie: I thought having lots of meat is a way to lose weight?
Sister: Wrong, wrong, wrong! Having excessive meat or protein food will increase the workload of the kidneys. It increases urination and therefore a rapid weight loss in the beginning, but only reduced the body’s water content and could lead to dehydration. When our body is deficient in carbohydrates , it will switch to use our body fat as energy fuel and ketones will be produced. Accumulation of ketones would create odour in our breath, disturb the pH level of our blood, cause us to faint coma or even death. Furthermore, protein also contains energy and therefore having excessive protein food is actually fattening! Winnie, you often eat beef brisket and chicken skin rather than lean meat!
Grace: We should not eat poultry skin because of its high fat content, right?
Sister: Yes, Poultry skin is high in saturated fat which increases the risk of cardio-vascular diseases. 100 g of chicken with skin contains 58 kcal more than these without skin. Beef brisket also has relatively more fat, it is better to choose lean beef or trim off the visible fat before eating.
Winnie: What if I eat deep-fried fish fillet?
Grace: Deep-fried!? I think you better choose food which are cooked with less oil, such as steaming, stewing, baking, etc.
Winnie: Fine, maybe I won’t eat meat and just have rice with sauce.
Sister: Sauce is actually high in oil, salt and sugar! You should avoid excessive condiments such as tomato ketchup, oyster sauce, etc. When dine out in restaurants, you can order your food with “less sauce” or “no sauce”.
Grace: Winnie, I think drinking grapefruit juice can reduce body weight!
Sister: Grace, this is a wrong concept. Grapefruit belongs to the fruit family and all fruits contain energy. A medium grapefruit (248 g) has 78 kcal. There is no scientific evidence that sour food will reduce fat content of other foods or burn body fat. It is a good idea to have fruits as snack between main meals but not to replace main meals. A glass of fruit juices usually contains several pieces of fruits, excessive fructose can actually increase our body weight.
Grace: Winnie, you better do some exercise if you really want to lose weight.
Winnie: Ok, let me start by doing sit-up for 200 times everyday, that should reduce the fat at my waist.
Sister: Winnie, it is good that you are determined to do exercise, but there is no evidence that any particular exercise can reduce body fat at specific area. As sit-up is not an aerobic exercise, it can probably strengthen your waist muscle instead of reducing body fat.
Winnie: So what is aerobic exercise?
Grace: I know, the PE teacher said aerobic exercise included rope skipping, basketball, tennis, badminton, swimming, running, cycling, etc.
Sister: Yes. Aerobic exercise can strengthen the cardio-pulmonary function, increase the endurance, burn calories and prevent the accumulation of body fat. According to the recommendation of Centers for Disease Control and Prevention (CDC), children and adolescents should do at least 60 minutes physical activity of moderate to vigorous intensity everyday in order to stay healthy.
Winnie: Now I understand that the formulae for weight reduction is “balance diet + regular exercise”. Thank you so much my lovely sister. I will soon be fit and wear a pretty dress to attend the graduation dinner!

Reference

Pennington, J.A.T. Bowes and Church’s Food Values of Portions Commonly Used, 17th edition, 1998
https://www.cdc.gov/physicalactivity/everyone/glossary/index.html (3/2009)

Smart phone App

Student body weight for height check

Student Health Service, Department of Health has developed an App for iPhone and iPad as a tool for students to check their body weight for height. The App also provides health tips on diet and physical activities. There are fun games in the App too. At present, the App is only available in Chinese version and you are welcomed to download it from the iTunes website or Hong Kong App Store.


Bridge Blog

My views on “Weight Loss”:

Never skip breakfast even if you want to control weight. A nutritious breakfast is essential for an energetic school day.

What we want is to keep a healthy body weight! Don’t solely focus on “Weight Loss”!

Besides having no snacks and soft drinks, we also need to quit fat from meat and skin of poultry as well.

Avoid meals before bedtime if you wish to lose weight.

Being slim doesn’t mean beauty. So, don’t lose weight too fast and too much. In fact, being healthy is the most beautiful.

Doing regular exercise would be far more effective and long lasting to control weight and prevent accumulation of fat.


Bridge Chats

Mini: My mum said dinner is ready. But don't bother! Let's chat!
Baby: Why? You don't feel hungry? You don't like the food?
Mini: No! She has cooked some spare ribs. That's my favourite! But I won't eat. I want to lose weight!
Baby: Don't eat is no good! No food, no energy!
Mini: Slim is beauty! I just want to be slim!
Baby: If you don't eat, you'll have no energy. You can't concentrate in class or do homework, not to mention playing games!
Mini: Slim is OK!
Baby: You'll get sick and malnourished.
Mini: You are right! I won't look good if I'm sick!
Baby: Skipping food doesn't cause weight loss. Weight control is to have frequent small meals plus daily exercise for at least 1 hour!
Mini: OK! I am very hungry! I'll go for my dinner! Bye!

Junior Health Pioneer

Junior Pioneer asks Zhuzhu whether she is feeling unwell when he saw zhuzhu looks so unhappy.

Junior Pioneer: Zhuzhu you look so tired, are you not feeling well? Do you need to tell your parents and go to see a doctor?
Zhuzhu: NO please. Jade taught me how to lose weight quickly. That is skip all meals except lunch everyday. However, after trying it for 2 days, I feel tired for the whole day.
Junior Pioneer: You must stop this, the correct way of weight control is to keep a healthy diet and to do some physical exercise. Improper diet will affect our health.
Zhuzhu: Let’s me tell Jade this is an improper way to lose weight. Junior Pioneer, can you teach me something about weight control?
Junior Pioneer: No Problem. Let’s read this issue of Bridge. The dietitian of Student Health Service will teach us about weight control.

For enquiries of student's health problems, please e-mail to "Health Box"

E-mail Address: shsbridge@dh.gov.hk

Editorial Board Members: Dr. HO Chun-luen, David, Ms. LAI Chiu-wah, Phronsie, Ms. CHAN Shuk-yi, Karindi, Ms. CHOI Choi-fung, Ms. CHAN Kin-pui

Tel : 2349 4212 / 3163 4600 Fax : 2348 3968