Obesity

A famous ancient proverb states: eat breakfast like a king, lunch like an ordinary person, and your dinner like a beggar. These words of wisdom have long been discarded. Modern life has brought with it more food with high caloric density and better taste. New technology has made life easier and less active, and the result is a worldwide epidemic of obesity and its associated disorders.1,2 Obesity involves both increased fat cell size and number1 and occurs when energy

intake is greater than energy expenditure. This balance between

energy input and energy output can be affected by many factors

including the quality and quantity of dietary intake, environmental

and genetic inputs and physiological and psychological status.

Obesity is defined as accumulation of excess fat in body,

which is associated with adverse health outcomes.

Obesity has become a global problem affecting all societies

and age groups. There is an increased prevalence of

obesity among adults, adolescents and children in

developed as well as developing countries. Increased

prevalence of obesity gives rise to increase in obesity

associated morbid factors such as hypertension, diabetes,

dyslipidaemia, obstructive sleep apnoea, degenerative

arthritis and cancers. These associated co-morbid factors

invariably increase the health care expenditures of subjects

with obesity and complications associated with obesity.

Obesity means an amount of body fat that

exceeds the level generally considered

healthy for a particular height.

There are

many methods of measuring body fat, some

of which are expensive and time consuming.

Body mass index, which is inexpensive

and easy to calculate, is typically used as

a proxy. Health officials recommend that

individual health assessments should

consider other factors as well. Research

has demonstrated that a high BMI is

strongly correlated with the same negative

health consequences as high body fat,

although the association between BMI does

vary among ethnic groups.

BMI is a person’s weight in kilograms divided

by his or her height in meters squared. For

measurements in pounds and inches, BMI is

calculated using the following formula:

BMI = ( Weight in pounds ) x 703 divided by

(Height in inches) x (Height in inches)

Note: In the metric system, BMI is kg / height in meters2

While the rising epidemic of obesity is primarily attributed to sedentary lifestyle, poor

dietary habits and the aging of the population, secondary causes of obesity generally go

undetected and untreated. These include endocrinological disorders, such as Cushing’s

syndrome, polycystic ovary syndrome, hypogonadism and hypothyroidism, as well as

genetic, syndromic and drug-related obesity. We present an overview of the major

disorders associated with obesity, highlighting the pathophysiologic mechanisms and

discussing diagnostic and treatment strategies that are most helpful to practicing

physicians in recognizing and treating these generally underdetected and

undertreated disorders.

Obesity being an abnormality is caused by several factors which include:

1 Food consumption pattern: Dietary patterns of Malaysians have changed markedly, as evidenced from an analysis of

food availability in the past four decades (1960s – 2000). Although these data should not

be equated with consumption levels, food balance sheet data are useful in indicating

probable trends in food consumption patterns. In the absence of regular food

consumption surveys, these data do provide some useful information, within the

recognized limitations of such data (Tee 1999).

FAO Food balance sheet data have shown that there has been a trend of increasing per

capita availability of the major macronutrients calories, fat and protein, particularly the former two nutrients.

2 Energy Imbalance: Obesity can result from a minor energy imbalance, which lead to a gradual but persistent

weight gain over a considerable period. Some researchers have hypothesized that energy

imbalance is the result of inherited metabolic characteristics; whereas others believe it is

caused by poor eating and lifestyle habits, that is “gluttony and sloth”. 

3  Macronutrient composition of the diet : The association between energy intake and body weight relies on the ease with which

excess macronutrients can be deposited as adipose tissue. The energy cost of nutrient

storage is not identical for all macronutrients. The cost of fat storage from dietary fat is

the lowest, followed by carbohydrate and protein (Flatt 1978). Macronutrients with a low

storage capacity such as protein and carbohydrate will be preferentially oxidized when

intakes exceeded requirements. Hence, excess dietary fat is more likely to be stored in the

body and this capacity is unlimited (Astrup et al. 1994; Horton et al. 1995). The caloric

content of fat is also more than twice that of protein or carbohydrate.

Alcohol is not stored in the body thus all ingested alcohol is oxidized immediately. This

response dominates oxidative pathways and suppresses the rates at which other fuels are

oxidized. The obligatory disposal of alcohol will promote fat storage because it operates

at the expense of fat oxidation (Suter et al. 1992).

In summary, after a meal the body has a specific order in which it burns up the fuels, that

is, alcohol, followed by protein then carbohydrate and finally fat. 

COMPLETE POST LOADING...