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 WHAT IS OBESITY?
Obesity indicates excess in the amount of body fat. In the
occurrence of obesity there is an increase in the size or number of fat
cells in the body of the afflicted. This excess of fat can have serious
negative impact on the health. |
| 'Obesity' indicates an excess amount of body fat |
|
Though the terms 'obesity' and (being) 'overweight' are used
interchangeably, there is a definite difference between the two
conditions. Technically speaking being 'overweight' is the result of an
excess amount of body weight that includes the weight of muscle,
bone, fat and water. Whereas, 'obesity' indicates excess in the amount of
body fat only. As an example to understand the difference lets look at
the case of bodybuilders- a bodybuilder with a lot of muscle can be
overweight and still not be obese.
Body Mass Index (BMI) is the standard parameter used to measure
obesity. Obesity can be detected by using the BMI formula. BMI equals weight in kilograms divided by height in meters squared (MI = kg/m2 ).
For example, a man who is 5' 6"(1.68 meters) tall and weighs 85
Kg would have a BMI of 85/(1.68 x 1.68)
= 30.14. |
| If BMI is more than 30, the person is obese |
|
 |
 If BMI is less than 18.5, the person is underweight.
If BMI is in between 25 to 30, the person is overweight.
If BMI is more than 30, the person is obese.
If BMI is more than 40, the person is extremely obese. |
| Classification of Overweight and
Obesity by BMI |
 |
| Graph Details
WHO Global Info Base (infobase. who. int), universal time: 10/19/2006 5:36:47 AM |
| OBESITY AND ITS CONSEQUENCES |
 In an obese person
the chances of developing
atherosclerosis are high
compared to a normal
individual. Atherosclerosis is
a disease in which there is a
formation of fat containing
plaque on the walls of blood
vessels. This plaque may
block the blood vessels and
cut the blood supply to the
organs. In case, vessels supplying blood to the heart are blocked the
individual stands the risk of suffering form a heart attack. |
Atherosclerotic plaque is susceptible to injury. This injury can
result in the formation of a blood clot in the artery, which in turn can
block the blood flow to various organs including the heart. Obese
individuals have higher amount of substances responsible for clotting.
Therefore, chances of formation of clots are more in obese people
compared to normal individuals.
Obesity is associated with high levels of bad cholesterol and low
levels of good cholesterol. This is responsible for increased chances of
heart diseases. Deposition of bad cholesterol (LDL-C or Low Density
Lipoprotein Cholesterol) on the inner lining of blood vessels is
responsible for atherosclerosis, while at the same time good cholesterol
(HDL-C or High Density Lipoprotein Cholesterol) protects blood vessels
from atherosclerosis. |
Obesity is associated with increased chances of
Atherosclerosis
Heart attack
High bad cholesterol levels
Low good cholesterol levels
High blood pressure
Clotting in the blood |
|
| Obesity can cause enlargement of the left pumping chamber of
the heart. It may cause abnormal heartbeats (arrthymias) that, in turn,
may lead to sudden death. Obesity also is associated with raised blood
pressure, which is responsible for the development of various heart
diseases. |
| Obesity reduces sensitivity of the body to insulin |
|
Obesity causes reduced sensitivity of the human body to
insulin- a substance that reduces the blood sugar levels in the body.
Therefore, chances of seeing increased blood sugar levels are more
common in obese individuals. Increased insulin resistance in obese
people also reduces the responsiveness of the body to insulin, externally
administered in the treatment of diabetes.
It is also observed that obese children face the devastating
prospect of developing certain heart diseases by the time they reach
middle age, considerably earlier than is “normal”, due to their arteries
showing striking similarities to heavy smokers, owing to obesity. |
| OBESITY AND OXIDATIVE STRESS |
| To understand
the role of oxidative
stress in obesity it is
essential to know what free radicals are and
what one means by
oxidative stress. |
 |
| Free radicals generate oxidative stress |
|
An atom has protons and neutrons at its center and electrons
revolving around the center in orbits. In normal conditions, these
electrons are found in pairs. If an electron revolving around the center is
not paired, the species is called as a free radical. Free radicals are
unstable and highly reactive. To achieve stability they 'rob' electrons
from the surrounding molecules to produce an electron pair. Due to
this, the molecule from which the electron is removed becomes
unstable and turns into a free radical. This process of 'robbing' repeats
with the new free radical and the chain progresses. In this way, a single
radical is capable of producing a sequence of electron transfer reactions.
The process of the removal of electron is called as oxidation. And the
stress thus generated by the free radicals is called as oxidative stress. |
| Free radical are involved in
the development of many medical disorders |
|
| These free radicals are continuously generated in the human
body and they attack fatty acids and proteins in cell membranes and
cause damage. Free radicals also damage the DNA. |
| An obese person is vulnerable to excessive oxidative stress |
|
Oxidative stress plays a crucial role in the development of
obesity related complications. Obese people have shown to be
vulnerable to excessive oxidative stress1. In the occurrence of obesity
there is an accumulation of fats in the body. Accumulated fat produces
oxidative stress. Increased oxidative stress is a significant mechanism producing complications associated with obesity2.
It is observed that plasma lipids oxidize at a greater rate in obese
subjects compared to non-obese individuals. This oxidation of lipids generates oxidative stress3.
 Regular exercise is considered as the first step in the
management of obesity. But it is a fact that exercise whether it is aerobic
or resistant, induces oxidative
stress. Research studies have
found that acute exercise
induces greater oxidative stress
levels in obese young adults
compared to their non-obese
counterparts. The study clearly
suggests that not only idle
obese people but also obese
people who exercise regularly
are exposed to the additional
burden of oxidative stress4. |
Effect of the exercise (20 min) on the
peroxidation of lipids (oxidative stress indicator) |
| ANTIOXIDANTS |
| Antioxidants are substances whose presence, in
relatively low concentrations, significantly inhibits the rate of oxidation.
It is considered to be the counter to the process of oxidation. |
| Antioxidants are substances that
tackle free radicals and control oxidative stress |
|
| Obesity is associated with increased oxidative stress
and lower intake of antioxidants |
|
| The problem of excess oxidative stress in obese individuals is
more complicated by the fact that obesity is associated with lower levels
of antioxidants such as vitamins E and A. A study has revealed that even
if obese individuals consume the same amount of vitamin A and E as
non-obese individuals, the levels of these antioxidant vitamins in their blood is found to be less compared to non-obese individuals. |
| ANTIOXIDANTS IN OBESITY |
Obesity is a problem that demands treatment efforts from
various fronts. To understand the role of antioxidants in obesity it is
necessary to understand the objectives of the treatment undertaken to
control obesity. The most important objectives to prevent and manage
obesity should include:
Reduction in weight.
Protection of heart and blood vessels.
Controlling blood sugar levels.
Managing oxidative stress generated by obesity. |
| OBESITY, ANTIOXIDANTS AND
WEIGHT MANAGEMENT |
| Antioxidants like Grape Seed extract and Green Tea
reduce the absorption of fats from digestive tract |
|
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| Lipases are the enzymes that are required for the absorption and
subsequent digestion of the lipids or fats. Grape Seed extract, an herbal
antioxidant, shows inhibitory activity on these enzymes. Inhibition of
the activity of lipases reduces absorption of fats from digestive tract into
the blood. It helps in reducing the fat content of the body. Additionally,
inhibition of these enzymes results in reduced accumulation of fat in
7 fatty tissue. Green Tea extract has also shown a similar action on lipases
as Grape Seed extract. |
| Green Tea is effective in
improving various parameters of obesity |
|
 When consumption of Green
Tea was assessed for its effect on the
body weight, the following advantages
were observed:
 Reduction in body weight.
Reduced waist circumference.
Reduced body fat mass.
Decreased fat under the skin
Reduction in BMI (Body Mass Index) |
| Green Tea stimulates breakdown of the fats |
|
| Green Tea extract and regular exercise when combined
stimulate breakdown of fats in the liver and muscle. This action of Green Tea reduces obesity caused by a high-fat diet. |
| |
 OBESITY,
ANTIOXIDANS
AND PROTECTION OF HEART
Obese individuals are more prone to heart diseases because of
various factors including higher cholesterol levels, high blood pressure,
increased chances of atherosclerosis, impaired heart function etc.
Various antioxidants offer protection to the heart in different ways.
Described below are some of the advantages. |
| |
| Antioxidant |
Advantage offered |
Reference |
| Aloe Vera juice |
Reduces bad
cholesterol (LDL-C). |
J Nutr Sci Vitaminol 2003 Aug;
49(4):292-6. |
| Grape Seed extract |
Decreases the
oxidation of LDL-C
and reduces oxidative
stress. |
Atherosclerosis. 1999 Jan;
142(1):139-49. |
| Grape Seed extract |
Improves the pumping
action
of heart in the
aftermath of a
heart
attack. |
Mutat Res. 2003 Feb-
Mar;
523-524:87-97. |
| Green Tea extract |
Reduces bad
cholesterol, at
the same time increases
good cholesterol. |
Arch Intern Med. 2003
Jun 23;
163(12):1448-53.
Brit. Med. J.,
310 : 693-
696. |
| Goji Berry |
Dilates blood vessels
and
reduces blood
pressure. |
Sheng Li Xue Bao.
1998 Jun;
50(3):309-14. |
| Noni Fruit juice |
Reduces blood
pressure. |
J Am Pharm Assoc 1960;
49: 271-3. |
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| OBESITY, ANTIOXIDANTS AND
BLOOD SUGAR CONTROL |
| Obese individuals are more prone to higher blood sugar levels.
Herbal antioxidants offer protection in this situation in more ways than
one. Listed below are some of the advantages. |
| Antioxidant |
Advantage offered |
Reference |
| Goji Berry |
Protects pancreas
and maintains
insulin secretion. |
Yakugaku
Zasshi 125(12)981-988. |
| Aloe Vera juice |
Reduces blood
glucose levels. |
Horm Res.
1986;24(4):288-94. |
| Goji Berry |
Improves sensitivity
of the body
to
insulin and
potentiates the
effects of insulin. |
YAKUGAKU ZASSHI
125(12)
981-988. |
| Grape Seed extract |
Shows insulinomimetic
effects(effects
that are
similar to
those of insulin). |
J Agric Food Chem.
2005 Jul 27;
53(15):
5932-5. |
| Aloe Vera juice |
Enhances the action
of oral
anti-diabetic
drugs. |
Phytomedicine
1996;3:245–248. |
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| OBESITY, ANTIOXIDANTS AND
OXIDATIVE STRESS |
Obesity is associated with the occurrence of higher oxidative
stress. Antioxidants, by reducing oxidative stress in the body, may
reduce the chances of obesity related complications. Various herbal
antioxidants like Mangosteen, Aloe Vera, Goji Berry, Grape Seed extract,
Green Tea, Noni Fruit etc. may support the human body and help fight
against free radicals that are generated in obesity.
Summary
ADVANTAGES OF ANTIOXIDANTS IN OBESITY
Reduced weight
Reduced absorption of fats
Increased break down of fats
Improved sugar control
Reduction in LDL-C (bad cholesterol)
Rise in HDL-C (good cholesterol)
Reduced blood pressure
Improved antioxidant defense |
| References |
Int. J. Obes. 26:1159-1164, 2002
J. Clin. Invest. 114:1752-1761 (2004)
Med Sci Sports Exerc. 2005; 37 (2): 213-219.
Med. Sci. Sports Exerc. 36:772-779, 2004. .
Pediatr. 134:160-165, 1999.
J. Pediatr. 130:653-655, 1997
Nutrition. 2003 Oct; 19(10): 876-9
J Nutr Biochem. 2000 Jan;11(1):45-51
Am J Clin Nutr. 2005 Jan;81(1):122-9
Crit Rev Food Sci Nutr. 2002 Mar;42(2):163-78. |
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