Introduction
The negative health effects of being overweight and
obese, many of which can be fatal include:
High blood pressure (hypertension)
High LDL cholesterol, low HDL cholesterol, or
high levels of triglycerides
Type 2 diabetes
Coronary heart disease
Stroke
Gallbladder disease.
Please note there is no such thing as the 'perfect
weight', we come in all shapes and sizes, but there are limits
within which we should be to be healthy!
In the medical profession, a doctor can't just
simply say that somebody is overweight, without reference to some kind
of statistical index, usually by one/both of the ratios described
below.
Equally healthy people can have quite
different weights, but there are some reasonably good indicators as
to when your weight is not what it should be 'ideally'.
In rich developed countries we are often
dealing with 'overweight' people eating too much rich fatty food,
but in poorer underdeveloped countries we are dealing 'underweight'
people, particularly young children suffering from malnutrition.
Malnutrition
means lack of proper nutrition, caused by not having enough to eat,
not eating enough of the right things, or being unable to use the
food that one does eat.
The Body Mass Index
The body mass index is a 'rough' guide to help
the medical profession decide whether is underweight, normal,
overweight or obese.
The higher your BMI the more fat you are
carrying - but not necessarily unhealthily.
Body Mass Index (BMI) = (body mass in kg) /
(height in m)2
When measured, you then consult a table of BMI
values to se where you fit in!
Table of BMI values (from
https://www.vertex42.com/ExcelTemplates/bmi-chart.html)
|
Body mass index |
Weight description |
|
less than 18.5 |
underweight |
|
18.5 to 24.9 |
normal |
|
25.0 to 29.9 |
overweight |
|
30.0 to 40.0 |
moderately obese |
|
over 40.0 |
very obese |
If you eat too much fatty sugary foods and
don't take enough exercise, most people will put on weight and too
much of it. You are taking in too much energy rich food for your
daily needs.
The excess energy releasing food is stored as
fat and gives you a raised BMI value.
Having a higher than normal BMI value
increases your risk of developing type 2 diabetes and cardiovascular
disease.
For more on this
see
The human circulatory system - heart, lungs, blood,
blood vessels, causes/treatment of cardiovascular disease
Note of caution: Having a high BMI is not
always unhealthy e.g. sports people train hard to build up extra muscle
which is heavier than fat, so they will tend to have higher than
'normal' BMI values and would not be classed as overweight.
The BMI calculation is easy e.g. for a person with
a body mass of 70.0 kg and a height of 1.80 m,
The BMI = m / h2 = 70 / 1.802
= 21.6 (3 sf,
kg/m2), suggesting the person is 'normal'.
BUT, beware, we do come in all shapes and sizes, even people on
healthy diets don't always 'fit in' with he BMI, but most doctors
consider it a useful and reasonably accurate diagnostic tool.
Note from 2020 on the covid-19 flue pandemic:
Research has shown that obese people are more likely to be seriously
ill with the virus than non-obese people - more severe fever, more
likely to be hospitalised and more likely to die!
The waist-to-hip ratio should also be taken into
consideration (see below).
The waist-to-hip ratio
Comparing the circumferences of waist and hips
is another measure of whether you are 'overweight' and concentrates
around one area where we can accumulate to much fat.
This index is all about fat distribution.
waist-to-hip ratio = circumference of waist
(cm) /
circumference of hips (cm)
The higher your waist-to-hip ratio the more
fatty tissue you are carrying around the middle of your body.
When measured, you then consult a table of BMI
values to se where you fit in!
Make sure you measure both diameters with the
same length units!
Table of waste-to-hip ratios (from
https://www.healthline.com/health/waist-to-hip-ratio)
|
Health risk |
waist-to-hip ratio (women) |
waist-to-hip ratio
(men |
|
low |
less than 0.81 |
less than 0.96 |
|
moderate |
0.81 to 0.85 |
0.96 to 1.00 |
|
high (overweight) |
over 0.85 |
over 1.00 |
The Waist to Hip calculation is easy e.g. for a
woman of waist measurement of 32 cm and a hip measurement of 40 cm,
The waist to hip ratio = 32 / 40 = 32 / 40
= 0.80 (3 sf,
no units), suggesting the person is 'fine'
(borderline low-moderate).
If you are female and your waist-to-hip ratio
is over 0.85 you are classed as overweight.
If you are male and your waist-to-hip ratio is
over 1.00 you are classed as overweight.
If you are above the moderate waist-to-hip
ratio values you are carrying too much fat around your 'middle' -
referred to as abdominal obesity.
Having a higher than normal waist-to-hip ratio
increases your risk of developing type 2 diabetes and suffering from
cardiovascular disease.
For more on this
see
The human circulatory system - heart, lungs, blood,
blood vessels, causes/treatment of cardiovascular disease
Again, beware, we do come in all shapes and sizes, but most doctors
consider it a useful extra diagnostic tool.
The body mass index (BMI) should also be taken
into consideration (see above).
