BMI - Body Mass Index

BMI, formerly called the Quetelet index, is a measure for indicating nutritional status in adults. 

It is defined as a person’s weight in kilograms divided by the square of the person’s height in metres (kg/m2). 

For example, an adult who weighs 70 kg and whose height is 1.75 m will have a BMI of 22.9.

70 (kg)/1.75 * 1.75 (m2) = 22.9 BMI

For adults over 20 years old, BMI falls into one of the following categories.

Overweight and obesity lead to adverse metabolic effects on joints, muscles, blood pressure, cholesterol, triglycerides and insulin resistance. 

Risks of coronary heart disease, ischemic stroke and type 2 diabetes mellitus increase steadily with increasing body mass index (BMI), a measure of weight relative to height. 

Raised body mass index also increases the risk of cancer of the breast, colon, prostate, endometrium, kidney and gall bladder. 

Mortality rates increase with increasing degrees of overweight, as measured by body mass index. 

To achieve optimum health, the range of 21 to 25 kg/m2...... 

while the goal for individuals should be to maintain BMI in the range 20 to 25. 

There is increased risk of co-morbidities for body mass index 25.0 to 29.9, and moderate to severe risk of co-morbidities for body mass index greater than 30.

Assortment of fresh fruits and vegetables

 Table - Nutritional status

BMINutritional status

Below 20


20 - 25

Normal weight

25 – 30



Obesity class I


Obesity class II

Above 40

Obesity class III

The BMI ranges are based on the effect excessive body fat has on disease and death and are reasonably well related to adiposity. 

BMI was developed as a risk indicator of disease; as BMI increases, so does the risk for some diseases. 

Some common conditions related to overweight and obesity include: 
premature death, 
cardiovascular diseases, 
high blood pressure, 
some cancers and diabetes.

BMI is also recommended for use in children and adolescents. 

In children, BMI is calculated as for adults and then compared with z-scores or percentiles. 

During childhood and adolescence the ratio between weight and height varies with sex and age, so the cut-off values that determine the nutritional status of those aged 0–19 years are gender- and age-specific. 

The cut-off points of the 2006 BMI-for-age reference for children aged 0–5 years for the diagnosis of overweight and obesity were set as the 97th and the 99th percentile, respectively. 

For those aged 5–19 years, overweight is defined as a BMI-for-age value over +1 SD and obesity as a BMI-for-age value over +2 SD.

Your BMI result


Being underweight could be a sign that you're not eating enough or that you may be ill. If you're underweight, your GP can help. Find out more in underweight adults.

Healthy weight

Keep up the good work. For tips on maintaining a healthy weight, check out our food and diet and fitness sections.


The best way to lose weight is through a combination of diet and exercise. The BMI calculator will give you a personal calorie allowance to help you achieve a healthy weight safely.


The best way to lose weight is through a combination of dietand exercise and in some cases medication. Contact your GP for help and advice.

Ethnicity and diabetes risk

Black, Asian and other minority ethnic groups (BMEs) have a higher risk of developing some chronic conditions, such as type 2 diabetes.

BME adults with a:

  • BMI of 23 or more are at increased risk
  • BMI of 27.5 or more are at high risk

Why waist size matters

Measuring your waist is a good way to check you're not carrying too much fat around your stomach, which can raise your risk of heart disease, type 2 diabetes and stroke.

You can have a healthy BMI and still have excess tummy fat – meaning you're still at risk of developing these diseases.

To measure your waist:

  1. find the bottom of your ribs and the top of your hips
  2. wrap a tape measure around your waist midway between these points
  3. breathe out naturally before taking the measurement

Regardless of your height or BMI, you should try to lose weight if your waist is:

  • 94cm (37ins) or more (men)
  • 80cm (31.5ins) or more (women)

You are at very high risk and you should contact your GP if your waist is:

  • 102cm (40ins) or more (men)
  • 88cm (34ins) or more (women)

Children's BMI

For children and young people aged two to 18, the BMI calculator takes into account age and gender as well as height and weight.

Obese children are thought to be at increased risk of a variety of health conditions, and they're also more likely to be overweight or obese as adults.

The BMI calculator works out if a child or young person is:

A child's BMI is expressed as a "centile" to show how their BMI compares to children who took part in national surveys. For example, a girl on the 75th centile is heavier than 75 out of 100 other girls her age.

Measuring waist size is not routinely advised for children because it doesn't take their height into account.

If you're concerned about your child's weight, contact your GP who may be able to refer you to your local healthy lifestyle programme for children, young people and families.

Limitations of the BMI

Your BMI can tell you if you're carrying too much weight but it can't tell if you're carrying too much fat. The BMI can't tell the difference between excess fat, muscle, or bone.

The adult BMI does not take into account age, gender or muscle mass. This means that: 

  • very muscular adults and athletes may be classed "overweight" or "obese" even though their body fat is low   
  • adults who lose muscle as they get older may fall in the "healthy weight" range even though they may be carrying excess fat

However, the BMI is a relatively straightforward and convenient method of assessing someone's weight. 

Your can use your BMI result as a starting point for further discussion with your doctor about your weight and your general health.

If you're suffering from an eating disorder, the BMI calculator results do not apply. 
Please seek further advice from your doctor.

References ........

You can calculate BMI using below website.......

Healthy but not tasty 

To be eaten raw ....500 gm to 800 gms... 

10 portions a day......each portion is 80 gm

 So over 3/4 kg or more daily........

This contains all vitamins, nutrients, minerals, protein, essential fat and carbohydrate - for good digestion and health....

Forget 5-a-day, think 10-a-day! New fruit and veg advice

Your parents and teachers have probably told you to eat up your fruit and veg.

Or you may have even heard the advice we should eat five different fruits or vegetables every day.

Well new research carried out by Imperial College London thinks we should be trying to eat more like 10 different fruit and vegetables every day.

And if you're a fan of potatoes, some bad news for you.......

Deep-frying spoils all natural healthy benefits of vegetables and fruits

Always half-fry vegetables for beneficial effects on health

A quick fix for good health?

Eating a diet rich in some antioxidants has been shown to protect against the development of coronary heart disease, strokes, some cancers and age-related diseases. 

Supplements: a waste of time?

The majority of clinical trials to date have found no evidence that taking individual or combinations of antioxidants can offer healthy people protection against disease.

          Taking too many vitamin supplements can lead to this unwanted side effect

Luckily nature has provided us with a balanced package of antioxidants.

There is certainly no evidence to suggest that eating plenty of fruit and vegetables can be bad for you.

Taking many vitamin supplements can lead to unwanted side effect

The pills could irritate the oesophagus, or allow some stomach acid to creep back up the oesophagus when it enters the stomach.

The pills could irritate the oesophagus, or allow some stomach acid to creep back up the oesophagus when it enters the stomach.
There's no definitive evidence that they confer health benefits.
Eating plenty of fruit and vegetables, and whole grains, should help to regain the extra nutrients that the body needs…… may be a good idea to stop taking the supplements altogether.
Liquid vitamins could be an alternative. It will be easier to swallow and minimise irritation.

Eat a rainbow

Catherine Collins, principle dietician at St George's Hospital NHS Trust, recommends eating more plant foods such as vegetables, fruits, pulses and grains, which are all rich in dietary antioxidants and also a good source of fibre.


Healthy foods  

A woman eating spinach

No Super Food or Magic Bullet to solve dietary needs

A big problem is our focus on individual nutrients or ingredients. 

This takes the focus away from fresh produce and towards processed foods. 

Our fixation with specific vitamins or mineral also creates an environment in which manufacturers can add nutrients to food and make health claims for those foods. 

Nutritionist Stanton is yet to find an Australian deficient in the sort of nutrients that go into fortified cereals 

“Then it achieves a health halo and it sells, and you see this with heavily sweetened breakfast cereals. Stanton points out that she is yet to find an Australian deficient in the sort of nutrients that go into fortified cereals. 

In general, same age-old dietary wisdom still holds: lots of fresh fruit and vegetables, whole grains, small amounts of protein, particularly fish and seafood. 

Which foods can improve your gut bacteria?

While the homemade foods and products made by traditional methods contained a wide array of bacteria, some of the commercial products contained barely any.

"Typically, with commercial varieties, they would be subjected to pasteurisation after preparation to ensure their safety and extend their shelf life, which can kill off the bacteria, whereas that wouldn't be the case for the homemade varieties," says Dr Cotter.

So if you want to try fermented foods to improve your gut health's best look for products that have been made using traditional preparation and processing..................or make them yourself, to ensure you're getting the healthy bacteria you're after.

Jerusalem artichokes

Jerusalem artichokes are rich in prebiotic fibre


The dangerous myth of vitamin pills/ Anti-oxidants....

Far from being the elixir of life, antioxidants could send you to an early grave

(Credit: Alamy)

“The idea that antioxidant [supplementation] is a miracle cure is completely redundant,” says Enriquez.

Antioxidants have a dark side. Without free radicals, cells would continue to grow and divide uncontrollably

We now know that free radicals are often used as molecular messengers that send signals from one region of the cell to another. 

Without them, cells would continue to grow and divide uncontrollably. There’s a word for this: cancer.

We would also be more prone to infections from outside. When under stress from an unwanted bacterium or virus, free radicals are naturally produced in higher numbers, acting as silent klaxons to our immune system. 

In response, those cells at the vanguard of our immune defense – macrophages and lymphocytes – start to divide and scout out the problem. If it is a bacterium, they will engulf it like Pac-Man eating a blue ghost.

It is trapped, but it is not yet dead. To change that, free radicals are once again called into action. Inside the immune cell, they are used for what they are infamous for: to damage and to kill. The intruder is torn apart.

From start to finish, a healthy immune response depends on free radicals being there for us, within us.

How exercise in old age prevents the immune system from declining

Doing lots of exercise in older age can prevent the immune system from declining and protect people against infections, scientists say.

They followed 125 long-distance cyclists, some now in their 80s, and found they had the immune systems of 20-year-olds.

Prof Norman Lazarus, 82, of King's College London, who took part in and co-authored the research, said: 

"If exercise was a pill, everyone would be taking it.

"It has wide-ranging benefits for the body, the mind, for our muscles and our immune system."

Steve Harridge, professor of physiology at King's College London, said: "Being sedentary goes against evolution because humans are designed to be physically active.

Do it for health, because it's sociable, and enjoy the freedom it gives you."

He said: "I cycle for a sense of wellbeing and to enjoy our wonderful countryside."

Eating slowly helps lose weight: 

chewing properly & drink more eat less..

A study has found that eating slowly and having smaller bites makes us feel less hungry an hour afterwards than if we wolf down food.

People who ate slowly also drank more, which helped them feel fuller, the researchers said.

If you're trying to lose weight, eating slowly and more mindfully can help you eat less and lose weight. 

Recent research has proven that it takes time for the brain to realize that it is no longer hungry. 

When you consume your food quickly, your brain may fail to register how much you've actually eaten and may cause you to end up eating too much. 

Many studies have shown that eating more slowly and more mindfully can help you eat less and manage your weight.

Incorporate some easy ways to slow yourself down during meal time to help manage your weight more effectively.