Click Here To Subscribe

Search This Blog

Saturday 24 October 2015



Perhaps no area within the field of human nutrition is more intensively researched and discussed than the subject of obesity. In spite of all the research and discussions, it remains a disorder for which there is no clearly known cause or reliable treatment. This major public health problem is one of the most complex and misunderstood disorders of our time.

Interest in solving the mysteries surrounding the cause and cure of obesity is intense because the condition poses serious threat to health. Although it is the direct cause of death for only one disorder, obesity is associated with a wide range of conditions. Obesity is associated with a wide range of conditions. The increased risk of developing heart disease, diabetes, certain types of cancer, hypertension, and other disorders may contribute to shortened life span and decreased quality of life for people who are obese.
A consequence of obesity that has perhaps the greatest impact on quality of life stems from people’s attitudes about it. Obesity is a visible disorder, against which many people hold strong biases. Biases against obesity translate subtly or overtly into job discrimination, social isolation, ridicule, and rejection. The consequences of obesity are much better understood than its causes. The scientific literature does ,however, offer several theories about its causes.

The difficulty of identifying the root causes of obesity clearly indicates how complicated it is. we know that whatever causes behaviors of conditions that produces obesity results in a positive energy balance-caloric intakes that exceed the body’s need for calories. What is not known with any certainty is why some people develop eating habits or other conditions are so difficult to modify.

Two theories about the causes of obesity have contributed to our knowledge: the ‘nature’ theory and the ‘nurture’ theory. The nature theory attempts to explain obesity by genetic (inborn) traits. The nurture theory examines the roles of environmental factors such as early childhood food experiences and exercise in obesity development. Neither theory adequately explains why people become obese ; it appears that ‘nature’ and ‘nurture’ each plays a role

The Nature Theory The Nurture Theory
Obesity is linked to genetic traits inherited from parents
Obesity is related to overeating habits formed in childhood
There appear to be “natural” differences in individual rates of
thermogenesis psychological factors
The Nuture Theory
Some animals are genetically obese, so perhaps some humans are, too
Routine availability of highly preferred foods
Each person has a biologically determined weight.
Increased fat cell numbers due to overeating

Are some people born with tendency to become obese? Evidence supporting this notion has been found in studies of obesity in families and twins. To sort out the effects of upbringing and genetic traits on obesity development, scientists have studied twins adopted at birth. In general, twins raised by adoptive parents tend to have body builds similar to those of their biological parents.

The genetic links to obesity uncovered in twins studies and the findings of individual differences in thermogenesis strongly supports a genetic component to obesity, but they do not explain all cases of obesity. only four out of ten obese children become obese adults; most obese adults were of normal weight as children and infants.

The Nurture Theory: Two important factors associated with the development of obesity appear not to be related to genetic traits: eating habit and physical activity habits. Children learn to eat to satisfy hunger as well as for reasons unrelated to the need for food. Instead of eating to cure hunger pangs, they may learn to eat to relieve boredom, to escape a stressful situation, or to please their parents. Consider parents who insist that children “clean their plates” or who reward good behavior with cookies, candy, or other high-calorie treats. The child’s natural eating cue – hunger – may become obscured by other eating signals. Eating habits that develop during childhood can be very difficult to change.The types of food available to a person may influence whether the person eats too much and becomes obese.

Handling Obesity
Whatever the cause of obesity, nature, nurture, or a combination of the two – it is a condition that is very
hard to change once established. The tenacity demonstrated by the human body in maintaining obesity once established has led scientists to look for body mechanisms that act to maintain the obese state. So, far, two major body mechanisms that may promote the maintenance of obesity have been uncovered. The first has to do with the number of fat cells obese people produce, and the second with the body’s “idea” of its ideal weight – I e the “set point” theory of obesity.

Fat cells and Obesity: Observations that obese people tend to have more fat cells than normal –weight people once led many people to believe that the number of fat cells a person forms during childhood and adolescence is responsible for the maintenance of obesity. It was assumed that fat cells, like nerve or muscle cells, increase in number only during growth periods. If a person overate during childhood, it was reasoned, he or she would form an excess number of fat cells. This high level of fat cells would tend to make and keep the person obese.

It now appears that humans can add fat cells throughout life. When a person’s existing fat cells reach the maximum size (by becoming stuffed with stored fat), the body produces new cells to handle the need for additional fat storage. The presence of a high number of fat cells appears to make it difficult to lose weight. It has been suggested that the body may trigger eating signals when the amount of fat stored in the fat cells begins to decrease.
Set Point Theory: The set-point theory of obesity holds that each person is “programmed” to weigh a certain amount or to contain a particular level of body fat. If you weigh less or more than this predetermined amount or have a lower or higher level of fat, your body will automatically make adjustments in food intake or in the amount of energy expended for basal metabolism or thermogenesis so that you get back to your “set point” According to this theory, people become obese because they have high set points.
Scientific evidence that supports the set-point theory is limited. However, the theory offers an attractive explanation for why most people regain lost weight. Many people who manage to reduce their body weight and keep it at the lower level report that they have to “diet” constantly; if they eat enough to satisfy their desire for food, they regain the weight .

Most examinations of the possible causes of obesity led to the same conclusion: it is easier to prevent obesity from developing than to try to undo it once it has been established. Preventing obesity is viewed as the most effective way to “cure” the problem.


The surest route to the prevention of obesity is the early establishment of healthy eating and exercise patterns. Children are less likely to overeat if they are not encouraged (or forced) to clean their plates, not encouraged to eat when they are not hungry, and not rewarded with food. Small children know why they feel hungry, and they should not be encouraged to eat when they are not hungry or to continue eating when they have had enough. Parents should control what foods are available to their children. Children appear to be much better judges of when and how much they should eat then they are of what they should eat. Children are not born knowing how to select a balanced diet, they have to learn that

The chances of children becoming obese are decreased if they are physically active. Children who spend most of their free time watching television for example, are more likely to be obese than children who play actively during their free time. Children who enjoy spots and other forms of physical activities may be more likely to engage in exercise in their adult years. Children’s attitudes toward eating and physical activity are influenced by their parents’ behaviours. This makes the prevention of obesity a family affair. The “do as I say , not as I do” approach rarely works. Establishing good habits in children sometimes must begin with correcting the poor habits of adults.

Ref:  The Science of Human Nutrition by Judith E Brown pages 106, 108 & 109-111


Post a Comment