About Drinking Cold Water and Hot Water

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What Science Reveals About Drinking Cold Water: Is It That Bad for Your Health?

Drinking water is necessary for human health and survival, and drinking clean water—regardless of temperature—is never bad for your health. No scientific evidence supports a general statement like "cold water is bad for you," though there are circumstances when warm water is better.

The advent of TikTok and other social media platforms has brought ancient Ayurvedic and traditional Chinese medicine (TCM) practices—such as drinking warm or hot water rather than cold—into the current zeitgeist. Centuries of anecdotal evidence support the theory that room temperature and warm water are optimal for health and digestion. However, these practices can be taken out of context, resulting in rumors that drinking cold water is "bad for you."

What Makes Cold Water "Bad"?

It May Thicken Nasal Mucus

As a child, you may have been told not to drink cold water when sick. It's true that when you have a cold or infection, your body produces mucus that's thicker and stickier than normal.

A 1978 study of 15 healthy participants found that drinking cold water significantly decreased nasal mucus flow rate, whereas both hot water and hot chicken soup increased it. Researchers concluded that drinking hot liquids is better than cold liquids for managing mucus in people with upper respiratory tract infections like the common cold.

However, this study is very old and small and hasn't been replicated since, nor were the participants actually sick during the study. Ultimately, when you're sick, it's more important to prioritize drinking enough water rather than focusing on the ideal temperature to ensure you stay hydrated.

Marvels of Mucus and Phlegm

The Slime That Keeps You Healthy

Mucus has several names. Snot, the sticky goo that pours from your nose during a cold. Or phlegm, the gunk that can clog your lungs and make you cough. You probably aren’t a fan of the stuff. But mucus is so much more than a runny nose. Your body is making mucus all the time. And it plays an important role in keeping you healthy.

Mucus and phlegm get sort of a bad reputation . People think about it as something you’re supposed to cough up and get out. That it’s a bad thing. But in truth, mucus really is the interface between you and the outside world.

Mucus lines the moist surfaces of your body like the lungs, sinuses, mouth, stomach, and intestines. Even your eyes are coated with a thin layer of mucus. It serves as a lubricant to keep tissues from drying out. It’s also a line of defense.

  Mucus is very important for filtering out materials that you breathe in through your nose, such as dust and allergens and microorganisms. Anything that you breathe in gets stuck in the mucus, like flypaper.

Mucus at Work

In the next hour, you’re going to inhale thousands of bacteria. But you’ll never know it. Bacteria land on the mucus-lined surface of the lungs and get trapped. Then little hairs called cilia go to work. They push the mucus up and out of the lungs with all the trapped bacteria, viruses, and dust.

  It comes up at sort of a nice slow rate to the back of the throat. And if you’re normal and healthy, you never feel it and you just swallow it.

The mucus, together with the bacteria and other trapped substances, then goes to the stomach and eventually pass out of the body.

Your body makes a lot of mucus, although no one’s quite sure how much. Mucus is mostly water. But it also contains special proteins, sugars, and molecules that help the body control harmful germs.

Usually you’re not aware of all the mucus that slowly flows through your body. That is, until you get sick.

Too Much Mucus

You usually only notice mucus when you’re making too much of it. Or if it changes consistency.

An infection can make mucus thicker and stickier. Infections also lead to inflammation in the mucous membranes that line the nose and the rest of your airway. This can cause certain airway glands to make more mucus. That mucus can get thick with bacteria and cells that arrive to fight the infection. That can stimulate even more mucus production.

  When mucus is particularly excessive, it can be bothersome in terms of runny nose, clogged nose, and post-nasal drip. Post-nasal drip is when excess mucus from the back of the nose gathers and drips down the back of the throat. It’s a common cause of a cough.

Allergies can also cause your body to make extra mucus. When you have an allergy, your immune system overreacts to a harmless substance, like pollen, dust, or animal dander. Cells in your airway then release substances, like histamine.

Histamine can make you sneeze. It also causes the mucous membranes in the nose to swell and the glands to make more mucus.  Studies how certain proteins on immune cells control allergies and inflammation. They’re also looking at how certain components of mucus might help fight inflammation.

There are two general types of secretions that that are made in the nose. Things like allergies, eating spicy food, and being outside in the cold can result in a more watery nasal leakage.

Your body usually makes thicker mucus when you have a cold (caused by viruses) or sinus infection (caused by bacteria).

Most mucus problems are temporary. But producing too much mucus contributes to some serious conditions. This includes cystic fibrosis, a genetic disorder that causes mucus in the lungs to become thick and glue-like. Boucher and his colleagues are working to find new treatments for cystic fibrosis and related lung diseases.

Colors of Mucus

Mucus can come in a range of colors. This won’t surprise you if you’ve ever looked closely at your tissues after blowing your nose.

Mucus is normally clear. During a cold, you may find that your snot is cloudy or yellowish. Proteins released by the cells that cause inflammation can get stuck in the mucus and give it this color, Lane explains. He’s currently studying how cells in the nose and sinus are involved in long-term inflammation, called chronic sinusitis.

Brown or black mucus is more common in heavy smokers and some types of lung disease. Greenish, brownish, or bloody colors may signal a bacterial infection.

But that’s not always the case. It can be difficult to figure out what’s wrong simply by your mucus color. Since many things can cause your body to make too much mucus, doctors rely on other clues to diagnose and treat the problem.

Wonders of Mucus

While excess snot and phlegm aren’t pleasant, you wouldn’t want to go without mucus.

Mucus creates a layer of protection between the outside world and you. So it’s very, very important.

It’s not just important for people. It’s also the slime that allows a snail to move across the ground. It’s the slippery coating that protects fish against bacteria in the water. It’s a really wonderful material.

But maybe your mucus isn’t feeling so marvelous. If excess mucus is getting you down, see the Wise Choices box for tips on getting rid of it.

Wise Choices

When There’s Too Much Mucus

Use a humidifier or vaporizer. Keeping your nose and throat moist may reduce mucus and phlegm production.

Apply a warm, moist washcloth to your face. 

Try a nasal saline spray or rinse. Clearing out mucus can help you breathe easier. Commercial products are available. If making your own, only use distilled, sterile, or previously boiled water.

Consider taking over-the-counter medications. Expectorants can thin mucus to help clear it from your chest. Decongestants shrink blood vessels, so you produce less mucus. (Be careful about overusing them, as they can make the problem worse.) Antihistamines can help if your mucus is caused by allergies. 

It ( cold water )May Worsen Headaches

A 2001 study found that 51 out of 669 female participants (7.6%) experienced a headache after drinking 150 millimeters (ml) of ice-cold water through a straw. Notably, women who had a history of migraine within the last year were twice as likely to experience a headache after drinking the cold water.

Based on that older study, it's clear that drinking cold water does not cause headaches in everyone, but it's possible that it could be a trigger in some people with migraine.

However, more recent research shows that cold therapies like cold packs and intraoral cooling devices (prescription devices used to cool the mouth) actually help immediately reduce migraine symptoms. Drinking cold water was not included in that research, but it stands to reason that while cold water might trigger migraines in some people, it could also help migraines in others.

When it comes to cold water and headaches, knowing your own body is best.

It ( cold water ) May Affect Digestion

One of the most common beliefs about drinking cold water is that it can be "bad" for digestion.

In Ayurveda—the ancient Indian healing system—cold water can dampen what's known as agni, the digestive fire.6 It's believed that the mismatch between body and water temperature leads to energy expenditure, making it harder to digest food. Ayurveda is a healing system that originated thousands of years ago in India.

Ayurveda means "the science of life" and focuses on restoring the body's balance.

The premise of Ayurveda is that wellness depends on a healthy balance among mind, body, spirit, and senses.

This balance is achieved through a personalized plan that can include massage, specialized diets, herbs and foods, exercise, detoxification, and rejuvenation therapies.

In TCM, drinking cold water can block qi (life force) by affecting the functioning of the spleen, kidneys, and stomach.

Traditional Chinese Medicine (TCM) is a holistic approach to treating a person’s mental and physical health problems. Traditional Chinese medicine is based on the theory that sickness stems from an imbalance in a person’s life force energy (known as qi). The goal of TCM is to restore harmony within an individual and balance the forces of yin and yang, which are components of qi , energy in Chinese.

One recent study examined how premeal water temperature affected gastric motility (involuntary muscle contractions that move food through the digestive tract) and energy consumption (how much food the participants ate). There were 11 male participants who, on different occasions, drank water at 2, 37, and 60 degrees Celsius (C)—or 35.6, 98.6, and 140 degrees Fahrenheit (F), respectively—one hour before eating.

The cold water trial (35.6 degrees F) resulted in fewer gastric contractions than the hot water trial (140 degrees F) during the one-hour period after drinking the water. The cold water trial also resulted in participants eating less food, with energy intake 19% lower than the 98.6 degree F trial and 26% lower than the 140 degree F trial.

In other words, the results of that study show that drinking cold water could result in slower gastric motility, a decreased appetite, and, therefore, less food consumption.

This study only had 11 participants, so it's challenging to draw definitive conclusions about cold water and digestion.

It ( cold water ) May Contribute to Achalasia

It's possible that drinking cold water could worsen symptoms in people with a rare disorder of the esophagus called achalasia. Achalasia affects the lower esophageal sphincter (a ring of muscles that connects the esophagus to the stomach), resulting in difficulty swallowing food and drink.

Cold water can trigger esophageal spasms and exacerbate achalasia symptoms.

In a 2012 study, researchers observed the effects of giving 12 participants with achalasia drinking water at varying temperatures (cold, room temperature, and hot). The study revealed that drinking cold water made achalasia symptoms worse.

In contrast, the researchers found that hot water reduced achalasia symptoms. They concluded that people with achalasia should aim to consume warm or hot drinks and avoid cold drinks.

It ( cold water ) May Increase Blood Pressure

It's possible that drinking cold water temporarily increases blood pressure due to a reflex called the pressor response. The pressor response occurs when blood pressure rises from drinking water (of any temperature). This blood pressure increase is much more significant among people who are dehydrated, of advanced age, or unwell, but it still happens in healthy individuals to a much smaller degree.

In a 2022 study, researchers investigated whether drinking cold water would lead to a more significant pressor response than room-temperature water among young adult and older adult participants who experience orthostatic hypotension. This is a sudden decrease in blood pressure upon rising. They found that when compared to room-temperature water, both cold flat and carbonated water led to a significantly more significant increase in blood pressure. Both age groups had an increase in blood pressure, but it was greater in the older group.

This increase in blood pressure isn't necessarily a "bad" thing since it is temporary. In fact, the researchers concluded that drinking cold water (flat or carbonated) could be a useful first-aid tool for treating people with acute hypotension, a sudden drop in blood pressure.

When to Drink Cold Water

Drinking water at any temperature is healthy for you. Below are some situations when you might prefer to drink cold water:

● After exercise

● Before a meal, if you're trying to consume fewer calories

● In hot or humid environments

● When you're feeling dehydrated

● When you're feeling faint

When to Opt for Warm Water Instead

There are also times when you might prefer warm or hot water. These include:

● For relaxation at night

● In cold environments

● To relieve bloating or digestive ailments

● When you're sick

What is the Ideal Water Temperature?

Based on a small 2013 study, 60.8 degrees Fahrenheit  [ 16 ° Celsius ] is a good drinking temperature if you've just exercised or are feeling dehydrated. In this study, researchers investigated how water temperature affected sweating and rehydration among six dehydrated people who had just participated in mild exercise.

They concluded that the "ideal" water temperature was 60.8 degrees F—roughly the temperature of cool tap water—because that was the temperature at which participants sweat the least but consumed the most water.

Ultimately, the best water temperature is the one that motivates you to drink water.

Drinking Hot Water: A Simple Habit With Significant Health Benefits

Best Time to Drink Hot Water

Drinking hot water may be more than just a comfort drink. In traditional Chinese medicine, warm or hot water is often prescribed to help improve overall health and wellness.

While more research is needed, available evidence suggests drinking hot water may help improve digestion and support weight management. What's more, some advocates of this practice report experiencing certain benefits, especially when drinking hot water first thing in the morning or before bed.

1. Maintains Hydration

Drinking enough water throughout the day is key to maintaining overall health and preventing dehydration, which occurs when the body doesn't take in enough fluids. Hydration directly impacts neurological function, digestion, skin health, and kidney function.

Drinking hot water (especially during the cold winter months) has a psychologically soothing effect, encouraging you to drink more water and replenish lost fluids.

2. Reduces Shivering in the Cold

Drinking hot water when the temperature drops may help reduce shivering by regulating the body's core temperature. Ingesting the warm liquid can temporarily raise the body's internal temperature, which could reduce the need for the body to shiver to generate heat.

Normal human body temperature (normothermia, euthermia) is the typical temperature range found in humans. The normal human body temperature range is typically stated as 36.5–37.5 °C (97.7–99.5 °F). The core body temperature of an individual tends to have the lowest value in the second half of the sleep cycle; the lowest point, called the nadir, is one of the primary markers for circadian rhythms. The body temperature also changes when a person is hungry, sleepy, sick, or cold.

Experts note that the benefits of drinking hot water increase with the amount consumed. In addition, drinking warm water while exercising in the cold can positively impact performance and comfort levels.

Drinking warm water may also help prevent mild hypothermia.

3. Improves Circulation

Heat and warmth expand blood vessels and improve circulation in the body. This is why temperature therapies like saunas and warm baths are often prescribed for various health benefits, including circulation.

Drinking hot or warm water may work in a similar way. Although heat temporarily warms your body internally, drinking hot water regularly can support blood flow. 

4. Improves Blood Flow and Reduces Pain

A warm drink may relax muscles and support pain reduction. Studies show that increased circulation from external heat therapy delivers blood, nutrients, and oxygen to the body's muscles and decreases lactic acid levels that can trigger muscle soreness.  Drinking hot water may also reduce pain, though more research is needed.

5. Supports Weight Loss

Drinking more water is a popular tactic for supporting weight loss because the metabolism process requires adequate fluid intake. Hot water might be a bonus because it increases body temperature and activates metabolism.

Drinking hot water rather than cold water may also support weight loss. In one study, consuming hot water (up to 98.6 degrees F—the same as “normal” body temperature) before a meal boosted metabolism for up to 40 minutes afterward.

Other research shows that drinking about 19 ounces of water increases the metabolic rate by 30%, suggesting that drinking more (hot) water throughout the day may lead to burning more calories and improved weight management.

6. May Aid Digestion

The digestive system requires hydration to move food through the body properly and maintain balance in the gut. Drinking warm or hot water helps digestion by relaxing the gastrointestinal tract muscles and keeping the body system running smoothly. Some case studies found that drinking hot or warm water before a meal supports digestion.

Animal research suggests that drinking warm water during cold seasons supports a healthy gut environment. However, more human studies are needed.

7. May Help with Constipation

Constipation, defined as having fewer than three bowel movements per week, is often triggered by not drinking enough fluids. Drinking hot or warm water could further support regular bowel movements.

Some research shows that consuming hot water at 98.6 degrees F positively supports the gastrointestinal system and bowel movements.

8. May Relieve Nasal Congestion

Inhaling steam is a popular home remedy for clearing nasal congestion, and drinking tea is often recommended when feeling unwell.

Inhaling the steam from and consuming a hot beverage (like water) can help nasal congestion by breaking up mucus and unclogging the sinuses. One study found that a hot drink offered more effective relief from cold symptoms (like a runny nose, sore throat, coughing, and fatigue) than a room-temperature drink.

9. May Improve Central Nervous System Function

The body's central nervous system requires hydration to function properly. Not getting adequate fluids can negatively impact certain brain functions and mood regulation.

A study found that drinking enough water supported brain activity during challenging activities, and reduced reported anxiety levels.

10. May Reduce Stress

Staying hydrated may help improve mood because it supports the central nervous system. Studies suggest that not drinking enough water decreases the ability to feel calm, satisfied, and other positive emotions.

Research also found that drinking hot liquids lowers stress levels and reduces anxiety symptoms.

11. May Aid Detoxification

Various detoxification programs and products claim to remove toxins from the body. Some experts argue that consuming hot water may be one of these detox methods. They theorize that by raising the internal body temperature (and triggering sweating), hot water consumption helps to expel toxins.

Drinking more water generally helps support kidney health by diluting waste in the bloodstream. In addition, rheumatologists (healthcare providers specializing in treating inflammatory diseases of the musculoskeletal system) have noted that water consumption is key for flushing out the body, combating inflammation, and keeping the joints lubricated.

12. May Relieve Achalasia Symptoms

People with achalasia, a rare disorder that makes it difficult to swallow food and drink, may benefit from drinking warm water. In one study, people with this condition experienced more pain and other issues with swallowing when drinking cold water. They reported that these symptoms improved when they consumed warm or hot beverages.

A Word From Me

Drinking warm and hot beverages can help increase core body temperature and improve digestion. If you do not like the taste of water alone, add 🍋 lemon , make herbal tea, or drink a clear broth. Make sure the water is cooled to a comfortable level before consumption.

What's the Best Time of Day to Drink Hot Water?

The best time of day for drinking hot water is a personal preference. Hot water right after waking up is a warm beverage alternative to coffee. Others note that sipping on warm water just before bed is a calming way to unwind for a good night's sleep.

Can You Get the Same Benefits From Tea or Coffee?

Consuming any liquid technically supports your daily fluid intake. However, coffee and certain teas contain caffeine, which may cause more frequent urination and fluid loss.

Plain (in this case, hot) water is your best bet for staying hydrated. While there isn't specific research on the benefits of different hot liquids, it's probably safe to assume that your fluid needs are supported whether you're sipping on a cup of warm tea, clear broth, or water.

Potential Risks

The practice of drinking warm or hot water is generally considered to be safe. Still, there are some potential risks and safety measures to take into consideration when you're dealing with beverages at hot temperatures, such as:

● Damaging esophagus tissue

● Temporarily burning taste buds

● Scalding the tongue

  Some research suggests that hot beverages can be safely consumed (and pleasantly enjoyed) at around 136 degrees Fahrenheit, though slightly cooler temperatures may also be preferred. To be safe, always allow your hot drink to cool down to a comfortable temperature before taking a sip.

Summary

While extensive research on the topic is limited, drinking hot water is a solid way to stay hydrated and potentially reap other health benefits, like improved digestion, weight management support, and reduced stress levels.

Whether you prefer hot water in the morning or at night, allow the beverage to cool to a safe temperature before consuming it to avoid burn risks. Hot water consumption is generally considered safe for most healthy adults. However, check with a healthcare provider if you have any underlying health conditions and are unsure whether this practice is suitable. 

Simple textbook science form 4

Chapter 3

Form 4

BY: MUHAMMAD ZUBAIR BIN ABD GHANI

2020983203

ACKNOWLEDGEMENT

The Publication of this textbook includes the cooperation of many parties. A big thanks to all parties that involved in this publication of textbook.

Website Publisher:

Author: Muhammad

Published in 2022

Published for School

Science (SCE 551)

By: SASBADI SDN. BHD.

No. 21, Jalan Bertam

Indah 3, Taman Bertam

Indah 13200 Kepala Batas,

Pulau Pinang.

i

INTRODUCTION

The Form 4 Science Kurikulum Standard

Sekolah Menengah (KSSM) is written based on Dokumen Standard Kurikulum (DSKP) and Pentaksiran Tingkatan 4. This book prepared based on a holistic approach Education Centre that aims to produce students that intelligient,

creative, innovative and high value. This book will help students to have better knowledge with lots of special features that have been develop in this book as follows:

● Mind map & Thinking map

● Information & Communication skills

● Critical thinking & Problem Solving

● Self-reliance skills

● Tips and Summary of topic

This book is made of qualified author where

the author is a graduation of Bachelor of

Education in Science with Honors. An online research have been made with preferences to make sure that there is no misleading information.

ii

TABLE OF CONTENT

Acknowledgement i

Introduction ii

Table of Content iii

THEME 1:

SCIENTIFIC METHODOLOGY

CHAPTER 3:

Technique of Measuring Parameter Body Health

3.1: Body Temperature 2

3.2: Pulse Rate 3

3.3: Blood Pressure 4

3.4: Body Mass Index (BMI) 5

References 6

iii

CHAPTER 3 Technique of Measuring

Parameters of Body Health

What is the correct technique to

measure body temperature?

What is pulse rate?

How blood pressure recorded?

What is Body Mass Index (BMI)?

What will you learn? INFORMATION!

Body Temperature

Pulse Rate One of healthy lifestyle is to

Blood Pressure have regular medical check-ups

Body Mass Index and not only sick people need to

see the doctor. We can make

sure our health in a good

condition and we also can learn

about how to measure the

parameters of our body health

with the correct technique.

1

3.1: Body Temperature

Temperature is a measurement of the degree of hotness and coldness of a substance. Body

temperature is the measurement degree of hotness and coldness of our body. We must

ensure our body temperature in a normal range.

Information!

Body temperature can be

measure with type of

thermometer.

Figure 1: Types of thermometer This is technique to use

temperature.

Clinical Thermometer can measure

temperature with an accuracy of 0.1 degree Photograph 1:

celcius. Laboratory thermometer can only Clinical measure with accuracy 1 degree celcius.

Thermometer

A normal body temperature is 36.9°C, if increase or decrease

Photograph 2:

happen, it shows that our body

Rectal not in good condition. Thermometer

Photograph 3

Infrared

Thermometer

Figure 2: Factor of sick 

3.2: Pulse Rate

Pulse rate is the measurement of the number of heartbeats (bpm). There are a few areas on the body where the pulse can be felt. These called pulse point. Doctors usually take pulse at wrist because it clear, perminent and easy.

In Figure 3, shows that the place of pulse point that can count the heartbeat.

Figure 3: Pulse Point

Lets do some experiment to count heartbeat!

Photograph 4:

Photograph 5:

Experiment 

3.3: Blood Pressure

Blood pressure is the pressure that blood exerts on the wall of the blood vessels. This pressure originates in the contraction of the heart, which forces blood out of the heart and into the blood vessels.

Additional Notes!

Sphygmomanometer and

stethoscope is used to

check blood pressure. It

also can be done at home

use the digital one.

Two mechanisms take place in the heart: diastole and systole. Diastole is the relaxation of the chambers of the heart and systole is the contraction of the heart chambers. Systolic pressure is thus the pressure that your heart emits when blood is forced out of the heart and diastolic pressure is the pressure exerted when the heart is relaxed. This is the main mechanism by which blood pressure operates.

Blood pressure is one of the principal vital signs. During each heartbeat,  blood pressure varies between a maximum (systolic) and a minimum (diastolic) pressure. A normal blood pressure should be around 120/80, with the systolic pressure expressed first.

Figure shows the reading of blood pressure.

Figure 4: Blood Pressure Reading

Normal blood pressure for most adults is defined as a systolic pressure of less than 120 and a diastolic pressure of less than 80. Elevated blood pressure is defined as a systolic pressure between 120 and 129 with a diastolic pressure of less than 80.

3.4: Body mass Index (BMI)

Body mass index (BMI) is a measure of body fat based on height and weight that applies to adult men and women.

Formula of Body Mass Index.

Figure 5: Formula BMI Information!

Studies show that lifespan of person with ideal BMI is 18.5 - 24.9 kgm.

Figure 6: Body Mass Index Chart BMI is used to evaluate body fatness. A BMI of 18.5 to 24.9 is considered normal for an adult. A higher number indicates an

increased level of fatness, with a BMI of

25.0 to 29.9 considered overweight. A BMI of 30.0 or more is considered obese. BMI calculation is affected by a person's age, race, gender and muscle mass, so these factors should be considered in the overall assessment. The calculation becomes more and more valid as a person's BMI increases.

Figure 7: Healthy Life 5

SUMMARY

PERFORMANCE EVALUATION

You have a fever if your body temperature is above 37 degree celcius.

Extreme cold also can cause body temperature to be below normal.

A) Based on statement above, state 3 factor that cause fever.

B) What is normal body temperature?

State the different between systolic pressure and diastolic pressure.

Explain briefly what is Body Mass Index and its formula.

Give 3 places that we can found heartbeat from pulse point.

State four types of thermometer and briefly about it functions.

REFERENCES

Odonata Publishing Sdn Bhd (2019) Science KSSM Textbook Form 4 Anyflip. Retrieved

from https://anyflip.com/qbqoq/iogk/basicxt

Ogedegbe G, Pickering T (November 2010). "Principles and techniques of blood pressure

measurement"

Ministry of Health Malaysia, (2012). Body Mass Index (BMI). Retrieved from http://www.

myhealth.gov.my/indeks-jisim-tubuh-ijt/

"Understanding blood pressure readings". American Heart Association. 11 January 2011.

Retrieved 30 March 2011.

Katz, Brigit (16 January 2020).

 "Human Body Temperature Is Getting Cooler, Study Finds". Smithsonian. Retrieved 22 January 2020.

Fischetti, Mark (2018), "Graphic Science: Goodbye, 98.6", Scientific American, vol. 319, no.6 (December)

The SuRF Report 2 (PDF). The Surveillance of Risk Factors Report Series (SuRF). World Health Organization. 2005.

"Body Mass Index (BMI)". Peter Yan Cardiology Clinic. Retrieved 8 July 2021.