Obesity: Environental or Genetic?


Obesity Environmental Vs Genetic
Introduction
Obesity is now one of the fastest growing epidemics of the 21st century. “Overweight and obesity are defined as abnormal or excessive fat accumulation that presents a risk to health. A crude population measure of obesity is the body mass index (BMI), a person’s weight (in kilograms) divided by the square of his or her height (in metres). A person with a BMI of 30 or more is generally considered obese”.
This report aims to provide a good understanding of obesity this includes:
• Illnesses and Medical Complications associated with obesity
• The Symptoms of Obesity Long and short term
• The Causes of Obesity
• The Diagnosis of obesity an explanation of BMI
The report also aims to answer the widely debated subject is obesity environmental or genetic? It is essential to identify the root cause of obesity between these two main factors genetics and the environment in order to be able tackle this growing epidemic. In order to that this the report has used some of the latest scientific articles from some of the most reputable institutions such as the MRC (Medical Research Council).
In addition the author of this report conducted a number of interviews with the Oxford Health Alliance (OxHA) which specialises in tackling chronic diseases especially obesity.
Scientific Theory
Obesity is now becoming one of the biggest health problems for the developed world. Obesity causes more than 9,000 deaths in the UK alone.
Over the last 25 years obesity in Adults has increased by four times as much as it used to be, resulting in two thirds of the UK being classed as overweight or Obese. Of these people are 22% men and 23% women.
According to figures from the National Audit Office, being obese can reduce your life expectancy by nine years. It also makes you far more likely to develop a range of chronic diseases and health-related problems, including:
• Diabetes • Heart Disease • Stroke
• Cancer • Osteoarthritis • High blood pressure
• Gallstones • Infertility • Depression
There are also a number of other medical complications that may arise from being obese.

Childhood Obesity

One common misconception is that obesity only occurs in adults when in reality there are a high number of children that have been diagnosed as Obese. In the last 20 years the number of obese children has tripled.
At Least 10% of six year olds and 17% of 15 year olds are now clinically Obese. Child obesity is often dismissed as puppy fat although many parents and carers fail to realise that the child runs a high risk of becoming obese resulting in serious health effects later in life.
Symptoms of Obesity
Becoming slightly overweight doesn’t cause much of an impact to your health although being overweight/Obese for a prolonged period of time can cause some serious health effects such as heart disease and high blood pressure.
The immediate Symptoms of Obesity include:
• Breathlessness • Sleep Apnoea (snoring)
• Difficulty Sleeping • Inability to cope with sudden physical activity
• Frequent tiredness • Back and Joint pains
In addition to the short term problems and the immediate symptoms to obesity, many people also suffer a number of psychological problems such as:
• Low level of Confidence • Low self-esteem (Self Worth), poor self image
• Feeling isolated in Society • Reduced Mobility resulting in poor quality of life
In the long term, obesity greatly increases your risk of:
• high blood pressure,
• heart disease and stroke,
• high cholesterol levels (fatty deposits blocking up your arteries)
• breast cancer
• gall bladder disease
• gastro-oesophageal reflux disease (when stomach acid flows up into the gullet)
• arthritis of the back, hips, knees and ankles,
• Diabetes
• Reduced life expectancy.

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The Causes of Obesity
There are a number of factors that contribute to the cause of obesity. The factors are:

Genetic Factors: A report on the Genetics of childhood obesity carried out by the department of genetics in the University of Cleveland has revealed that a variety of single gene defects can produce severe early onset obesity without associated neurodevelopment abnormalities or birth defects.
Environmental Factors: A healthy environment is essential for society to be able to be fit and healthy. There are many environmental factors that influence the rise in obesity such as:
• Transport- the way in which people travel
• Access to sports centres as well as open spaces to play and exercise
• Healthy Restaurants the access to healthy alternatives instead of being surrounded by Fast Food Restaurants selling food high in fat and salt
• Entertainment- these days people sit on the computer playing games or watching movies instead of walking to the cinema and playing in the park
Neurological and Physiological Factors: Many Obese people suffer from either psychological or physiological people. Neurological problems could be:
• Comfort eating
• Addiction to certain foods and beverages
• Weak self perception thoughts of being underweight or skinny
Physiological Problems could be:
• Low metabolic rate resulting in you putting on weight more easily
• Disabled- this person is not very mobile & will find it very hard to loose weight through exercise
• Heart problems this person is not aloud to exert themselves and it will be dangerous to do any cardio exercises
Cultural and Socio-economic Factors:
When identifying the causes of obesity it is essential to discuss the cultural and social economic influences in a person’s environment. There are many cultural and social economic influences such as:
• Bad eating habits
• Traditional food are high in fat and salt
• Poorer family’s can only afford packaged food which is generally high in fat, salt & sugar
• Fast food restaurants are seen as more fashionable and affordable
Biochemical: Certain chemical reactions in the body can influence obesity.
According to the European journal of obesity there are certain enzymes that can influence our appetite which dominates the amount we eat. The recent study discovers the enzyme GOAT (gherilin O-acetyltransferase) which is secreted in stomach acid although scientists still say they have a long way to fully understand the effects of this enzyme.
Diagnosis of Obesity
Creating a general diagnosis for obesity can be extremely difficult since each individual is different in terms of height, weight and body mass.
Although there is now a method of measuring obesity by using height and weight to calculate a persons Body Mass Index (BMI), this method is currently the most accurate and reliable way of measuring obesity. The calculation of BMI is being used by doctors and scientists all over the world to measure obesity.
To work out your own BMI you must use the following the calculation:
1. measure your height in metres and multiply the number by itself – this is the squared figure
2. Measure your weight in kilograms,
3. Divide your weight by the answer you got in step 1 (squared height),
4. The number you are left with is your BMI.
Here is an example:
1. 1.65 metres tall (165cm – 65 inches), your squared figure is 2.72
2. 58kg in weight
3. 58kg divided by 2.72
4. 21.3 BMI figure.
For the majority and Ideal weight is a BMI of 20-25.

The Diagram shows that BMI is not always the best measure of obesity. The Bodybuilder (left) and the Obese man (right) both have the same body mass index. Although the body builder has a very little percentage of fat and a larger muscle mass where as the obese man has a very high percentage of fat and is the unhealthy individual.
What are the Possible Treatments for Obesity
The most effective way to loose weight is to reduce your calorie intake and exercise more frequently. Any treatment for obesity aims to loose weight and improve ones quality of life both psychologically and physiologically.

There are four main options in the battle against obesity. These options are:
• You can do nothing and remain Obese
• Have a healthy diet and exercise regularly
• You can take different types of Drugs to help with weight lose
• You can pay for a Surgery
Diet
Maintaining a healthy diet is an essential step to losing weight as well as keeping healthy. When it comes to diet the secret is having a balanced diet which means having the correct proportions of everything even those fatty foods are essential for the body.
Below is a diagram of what a balanced diet should look like.

Figure details the constituents of a Balanced HEALTH Diet
Exercise
Exercise is important to be able to loose weight. Exercise helps you burn calories which is one of the crucial steps in loosing weight.
You should at least do about 30 minutes of exercise a day. It is usually best if you do that exercise with in a sport you enjoy whether it is dancing, swimming, playing football or even jogging, this will help you remain more consistent and exercise more muscle groups.
Drugs
There are a variety of medications available for weight loss. Although these medications are only available in extreme cases and given to you by your GP. You also need to show that you can loose weight on a calorie controlled diet before medication can even be considered.
The part of the brain responsible for controlling feelings like hunger is called the Hypothalamus. It is responsible for controlling the hormones and chemical signals circulating in our blood that influence appetite.
Traditional weight-loss drugs contain amphetamine, which is a stimulant that increases the activity of certain chemicals in the brain. Stimulants increase the amount of noradrenalin and dopamine hormones in your blood, which stops you feeling as hungry. However, they are not suitable for long-term use and can have serious side effects, including high blood pressure, anxiety and restlessness.
Surgery
People with a BMI of 40 or more are described as morbidly obese. At this stage, the problem can be very hard to treat. Surgery may be considered to restrict the amount of food eaten, or to interrupt the digestive process.
Surgery may also be an option for people with a BMI of 35 to 40, who have life-threatening cardiopulmonary problems – for example, severe sleep apnea (a sleep disorder where a person experiences irregular breathing at night), obesity-related heart disease, or diabetes.
Surgery is often seen as a last resort and should only be carried out after having tried and tested all methods. There are a number of surgical procedures such as:
• Gastric Banding
• Gastric Bypass
Gastric Banding
Advantages
Lowest mortality and complication rate
Least invasive surgical approach
No stapling, cutting, or intestinal re-routing
Adjustable
Reversible
Low malnutrition risk
Disadvantages
Slower initial weight loss than Gastric Bypass
Regular follow-up critical for optimal results
Requires implanted medical device
The figure above shows a gastric Banding system (Surgical Procedure) Courtesy Northwest Weight loss Surgery
Gastric Bypass

Advantages
Rapid initial weight loss
Laparoscopic approach is possible
Longer experience in USA
Disadvantages
Stomach Division, stapling and intestinal re-routing required
More operative complications than LAP-BAND
Portion of digestive tract is bypassed, resulting in nutritional deficiencies
“Dumping syndrome” can occur
Non-adjustable
Extremely difficult to reverse
The figure above shows a Gastric Bypass System (Surgical Procedure) Courtesy Northwest Weight loss Surgery
The Discussion: Is Obesity Environmental or Genetic?
Arguments for: Obesity is Environmental
1. Our food intake has increased rapidly over the years since the size of portions of food have increased massively over the years.
Portion sizes and type of food are modified to suit the varying needs, the www.MyPyramid.Gov of the USA Department of Agriculture offers personalised eating plans, assesses food choices, and provides advices.

2. Eat Healthy Food
The Healthy Eating Pyramid from the Department of Nutrition, Harvard School of Public Health is based on latest scientific evidence. The Pyramid is a simple, reliable guide to choosing a healthy diet. Its foundation is daily exercise and weight control, since these two related elements strongly influence your chances of staying healthy.


3. Obesity and Depression May Be Linked
A major review on the correlation between obesity and depression has been carried out by Science Daily one of the most reputable scientific journals in the united states and is known internationally for its reliability, reveals that research indicates people who are obese may be more likely to become depressed, and people who are depressed may be more likely to become obese.
Researchers led by Sarah M. Markowitz, M.S., examined the data that suggests there is a connection between depression and obesity. The study found that people who are obese may be more likely to become depressed because they experience themselves as in poor health and are unhappy with the way they look. This occurrence was particularly common among women and those of high socio-economic status.
Research also indicated that people who are depressed may be more likely to become obese due to physiological changes in their hormonal and immune systems that occur during depression. They also have more difficulty taking good care of themselves because of symptoms and consequences of depression, such as lack of motivation for going out, feeling of isolation loneliness, binge eating resulting in the individual becoming obese.
Treatments such as exercise and stress reduction can help to manage both obesity and depression at the same time. Dieting can potentially worsen mood, and antidepressants, which can cause weight gain, should be minimized. “The treatment of depression and obesity should be integrated,” the authors conclude. “This way, healthcare providers are working together to treat both conditions, rather than each in isolation.” Said the scientific journal Science Daily . This study is published in the March 2008 issue of Clinical Psychology: Science and Practice.
4. Obesity and Environmental Factors that Contribute to Obesity
http://www.health.state.ri.us/disease/ihw/environmental.php
In addition to the individual behaviours that contribute to the obesity epidemic, environments also play a role. Refer to the following chart to see how the environment we live in affects our physical activity and nutrition.
PHYSICAL ACTIVITY NUTRITION
Sedentary Pastimes
Children now spend more time in front of a screen than they do in school. Televisions, computers, and video games require no physical activity. Fast food
People are eating at fast food restaurants more often, so they have less control over how much fat, sugar, and salt is in their food.
Transportation
People are walking and cycling less because driving is often the easiest option. Many people feel that it is too dangerous to walk or cycle and find it easier to use their car. Growing Portion Sizes
Portions sizes in restaurants and fast food establishments are growing. In the 1950’s, a standard size coke was 6.5 ounces. Now, it is 20 ounces. That means the size has tripled.
Technological Advances
Things like computers, escalators, cell phones, dishwashers and lifts all reduce the need for physical activity. Soda and Junk Food
Soda has increasingly replaced milk and water in children’s diets.
Jobs
Most people have relatively sedentary jobs. This, in combination with longer work hours, has made it difficult for many people to be active during the day. Unhealthy School Environments
School lunch programs often don’t have a wide enough selection of healthy eating options.
Safety
In many communities, people do not feel safe walking outside or letting their children play outside. Sidewalks may not be lit up at night or there may not be any sidewalks at all! Advertisements
Unhealthy foods and drinks are aggressively advertised and sold to adults and children. In the USA commercials can last up to 3 hours where in England its only 3 minutes.
Green Space
Some neighborhoods don’t have many areas to allow for outdoor activities, like parks and fields. Access to Healthy Foods
Many low-income families do not have access to healthy foods, which are often much more expensive than processed foods.
Access to Sport Facilities
. Physical inactivity is the result of not having many accessible sports facilities to help fuel a child’s passion for sport or to even help children play sport and keep healthy. Schools also have very little or out of date equipment for sports.
5. The Environment and Behavioural Aspects
According to recent scientific studies in the last the number of obese people have tripled. This is due to changes in lifestyle, particularly changes in the foods that are available and the amount of physical activity people do.Foods now taste better and are a lot cheaper especially processed foods. Portion sizes are getting bigger, usually at very little extra cost. For convenience, more people are eating pre-packaged food, fast food and soft drinks, which are often high in calories, fat, salt and sugar. And these types of food are heavily advertised, especially to children.
We are also living more inactive lifestyles. The use of cars and public transport over walking and cycling is increasing. Many jobs now involve sitting at a desk for several hours. And inactive pastimes, such as watching television and surfing the internet, are becoming more popular.Cancer Research UK believes that an environment that encourages healthy eating and physical activity is essential in order to tackle obesity resulting in reducing the number of chronic disease such as Cancer, Heart disease and Diabetes.
We cannot alter our genetic make-up and it is very difficult to control our environment. But we can learn how to control the lifestyle choices we make.Because our calorie balance is controlled by instinctive drives, short-term ‘quick fix’ solutions (including most diet programmes) eventually fail. Instead, we must make long-term lifestyle decisions including healthy eating and regular physical activity to reduce our risk of being obese.
Resulting in a reduced risk of cancer, heart disease, diabetes and several other major diseases. Even relatively small losses, such as 10% of our total weight, can have positive effects on our health.
To find out more about how you can make small lifestyle changes to maintain a healthy body weight, go to our Ten Top Tips section.
For: Obesity is Genetic
1. New Genetics & Obesity Link discovered by John Reilly & David Wilson
According to one of the latest scientific studies conducted by the BMJ (British Medical Journal) and MRC (Medical Research Council) scientists have located an FTO gene in a region of the brain called the Hypothalamus that controls the feeling of hunger and thirst. The FTO gene is said to be able to manipulate these feelings leading people to eat more and become obese.
A group of scientists working with Professor Chris Ponting from the MRC Functional Genetics Unit in Oxford and Prof Stephen O’Rahilly, University of Cambridge, have made a large breakthrough in understanding how the ‘obesity gene’ triggers weight gain in some individuals. The team was led by Prof Chris Schofield from the University of Oxford working along with the university of Cambridge and Cancer Research UK in London, have been studying FTO, a gene that was linked to obesity earlier this year. These findings could have implications for the future treatment of obesity as well as adult onset diabetes.
Researchers discovered that variations in the FTO gene influences people’s risk of becoming obese. It has also been said that the discovery of the FTO gene was of significant importance because the genetic variant in FTO that influences obesity is very common.
New findings suggest that about 50% of the UK carry a copy of the variant FTO. As a result they are on average 1.6 kilograms heaver than those who don’t have the variant of FTO, while 16 per cent of the population carries two copies of the variant and are on average three kilograms heavier. Carriers of the variant also have an increased risk of diabetes.
They also found that FTO is highly expressed in the region of the brain called the hypothalamus, which has important roles in the control of hunger and satiety and that, in certain parts of the hypothalamus, the levels of FTO are influenced by feeding and fasting.
“This is an astonishing finding. We never expected this first obesity gene to have such a direct effect on DNA”, said Professor Ponting.
2. Genetics plays a key role in obesity
The International Journal of Bioinformatics Research and Applications have published evidence proving that genetics plays a key role in obesity. The research corresponds to the genetics of modern Pima Indians who have an abnormally high rate of obesity. Their obesity is thought to be linked to a low metabolism that is very efficient allowing them to metabolize food more efficiently in times when little was available, although this causes problems when food is in abundance.
The researchers anticipated an effect consistent with higher metabolic efficiency among these people and focused specifically on recently discovered variations in their mitochondrial DNA, so-called SNPs, or single nucleotide polymorphisms.
The metabolic rates of 200 obese Pima individuals were measured and revealed that two of the three known SNPs influence metabolic efficiency. The researchers then used the genetics software, to analyze the biochemical changes and then tracked the evolutionary selection of these genetic variations in 107 different types of mammals.
The team suggests that an increased metabolic efficiency could have been an evolutionary advantage. This helped the Pima Indians survive the harsh dietary environment of the Sonora desert. In the current environment of caloric over-consumption an increased efficiency is unfavourable and may contribute to the high rates of obesity among the Pimas.
The researches say while the Pima Indians are an extreme case, the entire human population may also have evolved in a restricted caloric environment. Many populations may exhibit similar cases that were advantageous to our ancestors but may now be unfavourable. These cases such as the Pima Indians provide an explanation as to why obesity is so prevalent in the 21st century.
3. Major Genetic Study Identifies Clearest Link Yet to Obesity Link
Scientists identified the most clear genetic link yet to obesity in the general population as part of a major study of diseases funded by the Wellcome Trust, the UK’s largest medical research charity. People with two copies of a particular gene variant have a 70 per cent higher risk of being obese than those with no copies.
Scientists from the Peninsula Medical School, Exeter, and the University of Oxford first identified a genetic link to obesity through a genome-wide study of 2000 people with type 2 diabetes and 3000 controls. This study was part of the Wellcome Trust Case Control Consortium, one of the biggest projects ever undertaken to identify the genetic variations that may predispose people to or protect them from major diseases. Through this genome-wide study, the researchers identified a strong association between an increase in BMI and a variation, or ‘allele’, of the gene FTO. Their findings are published online today in the journal ‘Science’.
The researchers then tested a further 37 000 samples for this gene from Bristol, Dundee and Exeter as well as a number of other regions in the UK and Finland.
The study found that people carrying one copy of the FTO allele have a 30 per cent increased risk of being obese compared to a person with no copies. However, a person carrying two copies of the FTO allele has a 70 per cent increased risk of being obese, becoming on average 3 kg heavier than a similar person with no copies.
The FTO gene was first discovered whilst studying the DNA of a group of patients with type 2 diabetes. The risk of developing type 2 diabetes increases significantly for obese people. Through its effect on BMI, having one copy of the FTO allele increases the risk of developing type 2 diabetes by 25%, having two by 50%.
“As a nation, we are eating more but doing less exercise, and so the average weight is increasing, but within the population some people seem to put on more weight than others,” explains Professor Andrew Hattersley from the Peninsula Medical School. “Our findings suggest a possible answer to someone who might ask ‘I eat the same and do as much exercise as my friend next door, so why am I fatter?’ There is clearly a component to obesity that is genetic.”
Conclusion
Obesity is one the fastest growing diseases and is quickly becoming a serious epidemic across the world. Obesity will cause an economic meltdown as it puts a major strain on national health services as it encourages the growth of chronic diseases such as cancer, diabetes and heart disease to a point where the quality of life will plummet more than ever before.
Therefore it is essential to identify the root cause of obesity in order to stop this growing epidemic. Although obesity can be triggered by a variety of factors and each change caused by these factors affects every individual differently. However obesity is caused by two main factors Genetics and the Environment the question is which one. Is our fate predetermined when we are born is it genetics that makes the decision? Do our genes decide our destiny, is it a case of once born fat you will remain fat? Or is the environment we live in crippling our health? Has the over consumption of processed food, the long periods of physical inactivity and our evolving sedentary lifestyle caught up with us?
According to many studies, the environment has been the root cause of obesity for many years. Many environmentalists and health care professionals suggest that as we enter a generation of technological advancements many basic tasks do no longer require physical activity and foods have higher levels of salt, sugar and fat than ever before we are going to continue to become obese at alarming rates unless, certain aspects of our environment are quickly changed.
Although ground breaking research suggests that genetics plays a big part in obesity. Scientists have located a gene called the FTO gene which can manipulate certain feelings such as hunger and thirst, which can cause obesity since an individual is not fully aware when he is full or no longer thirsty. This may provide an answer for those individuals who exercise more moderately and eat healthier than the majority but find it harder to loose weight.
Despite the promising results scientists have admitted they have yet to figure out how exactly this FTO gene works and whether genetics are solely responsible for an increase in weight. Therefore it is fair to say that the environment is the root cause for obesity at this stage between the two factors.
However I believe that it is a mixture between genetics and the environment and this will become more apparent as the research into genetics becomes more evident and we learn how to appreciate how the two factors affect each other.
Appendix
1) http://conservativehome.blogs.com/torydiary/images/obesity.gif
2) http://www.who.int/topics/obesity/en/ (World Health Organisation)
3) http://sitemaker.umich.edu/russette.356/comorbidities (The University of Michigan)
4) http://www.prohealthblog.com/images/stories/rising_childhood_obesity.gif
5) A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)
6) . National Heart, Lung, and Blood Institute Web site. Available at: http://www.nhlbi.nih.gov/guidelines/obesity/ob_home.htm
7) http://www.forthealthcare.com/media/images/obesity-table.gif
http://static.howstuffworks.com/gif/bmi-comparison.gif
9) http://www.thelapband.com/index.aspx Courtesy of North West Weight lose Surgery
10) Image from the Food Standards Agency Website www.food.gov.uk
11) www.MyPyramid.Gov
12) http://www.fda.gov/diabetes/pyramid.gif
13) http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/pyramid-full-story/index.html (Harvard University)
14) http://www.health.state.ri.us/disease/ihw/environmental.php
15) http://www.sciencedaily.com/releases/2008/06/080602152913.htm
16) http://info.cancerresearchuk.org/healthyliving/obesityandweight/whatcausesobesity/ (Cancer research UK)
17) http://bmj.com/cgi/content/full/333/7580/1207 (British Medical Journal)
18) http://www.physorg.com/news111753965.html
19) http://www.wellcome.ac.uk/News/Media-office/Press-releases/2007/WTX036897.htm (The Wellcome Trust)