An obese person has accumulated so much body fat that it might have a negative effect on their health. If a person's bodyweight is at least 20% higher than it should be, he or she is considered obese. If your Body Mass Index (BMI) is between 25 and 29.9 you are considered overweight. If your BMI is 30 or over you are considered obese.

The BMI is a statistical measurement derived from your height and weight. Although it is considered to be a useful way to estimate healthy body weight, it does not measure the percentage of body fat. The BMI measurement can sometimes be misleading - a muscleman may have a high BMI but have much less fat than an unfit person whose BMI is lower. However, in general, the BMI measurement can be a useful indicator for the 'average person'.

People become obese for several reasons, including:

1. Consuming too many calories.

 

People are eating much more than they used to. This used to be the case just in developed nations - however, the trend has spread worldwide. Despite billions of dollars being spent on public awareness campaigns that attempt to encourage people to eat healthily, the majority of us continue to overeat. In 1980 14% of the adult population of the USA was obese; by 2000 the figure reached 31% (The Obesity Society).

In the USA, the consumption of calories increased from 1,542 per day for women in 1971 to 1,877 per day in 2004. The figures for men were 2,450 in 1971 and 2,618 in 2004. Most people would expect this increase in calories to consist of fat - not so! Most of the increased food consumption has consisted of carbohydrates (sugars). Increased consumption of sweetened drinks has contributed significantly to the raised carbohydrate intake of most young American adults over the last three decades. The consumption of fast-foods has tripled over the same period.

Various other factors also may have contributed to America’s increased calorie and carbohydrate intake:

 

- In 1984 the Reagan administration freed up advertising on sweets and fast foods for children - regulations had previously set limits.

- Agricultural policies in most of the developed world have led to much cheaper foods.

- The US Farm Bill meant that the source of processed foods came from subsidized wheat, corn and rice. Corn, wheat and rice became much cheaper than fruit and vegetables.

 

2. Leading a sedentary lifestyle.

 

With the arrival of televisions, computers, video games, remote controls, washing machines, dish washers and other modern convenience devices, the majority of people are leading a much more sedentary lifestyle compared to their parents and grandparents. Some decades ago shopping consisted of walking down the road to the high street where one could find the grocers, bakers, banks, etc. As large out-of-town supermarkets and shopping malls started to appear, people moved from using their feet to driving their cars to get their provisions. In some countries, such as the USA, dependence on the car has become so strong that many people will drive even if their destination is only half-a-mile away.

The less you move around the fewer calories you burn. However, this is not only a question of calories. Physical activity has an effect on how your hormones work, and hormones have an effect on how your body deals with food. Several studies have shown that physical activity has a beneficial effect on your insulin levels - keeping them stable. Unstable insulin levels are closely associated with weight gain.

Children who have a television in their bedroom are much more likely to be obese or overweight than kids who do not, researchers from the Pennington Biomedical Research Center in Baton Rouge, LA, reported in the American Journal of Preventive Medicine (December 2012 issue).

3. Not sleeping enough.

 

If you do not sleep enough your risk of becoming obese doubles, according to research carried out at Warwick Medical School at the University of Warwick. The risk applies to both adults and children. Professor Francesco Cappuccio and team reviewed evidence in over 28,000 children and 15,000 adults. Their evidence clearly showed that sleep deprivation significantly increased obesity risk in both groups.

Professor Cappuccio said, "The ’epidemic’ of obesity is paralleled by a ’silent epidemic’ of reduced sleep duration with short sleep duration linked to increased risk of obesity both in adults and in children. These trends are detectable in adults as well as in children as young as 5 years."

 

Professor Cappuccio explains that sleep deprivation may lead to obesity through increased appetite as a result of hormonal changes. If you do not sleep enough you produce Ghrelin, a hormone that stimulates appetite. Lack of sleep also results in your body producing less Leptin, a hormone that suppresses appetite.

4. Endocrine disruptors, such as some foods that interfere with lipid metabolism.

 

A team from the University of Barcelona (UB) led by Dr Juan Carlos Laguna published a study in the journal Hepatology that provides clues to the molecular mechanism through which fructose (a type of sugar) in beverages may alter lipid energy metabolism and cause fatty liver and metabolic syndrome.

Fructose is mainly metabolized in the liver, the target organ of the metabolic alterations caused by the consumption of this sugar. In this study, rats receiving fructose-containing beverages presented a pathology similar to metabolic syndrome, which in the short term causes lipid accumulation (hypertriglyceridemia) and fatty liver, and eventually leads to hypertension, resistance to insulin, diabetes and obesity.

Poorly balanced diets and the lack of physical exercise are key factors in the increase of obesity and other metabolic diseases in modern societies. In epidemiological studies in humans, the effect of the intake of fructose-sweetened beverages also seems to be more intense in women. (From - "New Data On Fructose-Sweetened Beverages And Hepatic Metabolism").

Although there appears to be a consensus on the negative effects of fructose-sweetened beverages there is still some debate over the effects of fructose versus high fructose corn syrup - two studies of note are:

 

"AMA Finds High Fructose Syrup Unlikely To Be More Harmful To Health Than Other Caloric Sweeteners" and "Fructose Sweetened Drinks Increase Nonfasting Triglycerides In Obese Adults".

Fructose effect on the brain may promote obesity - researchers from Yale University School of Medicine compared the effects of fructose and glucose on the brain with MRI scans and found that high fructose diets may be behind the current obesity epidemic.

In an article published in JAMA (Journal of the American Medical Association), the authors said they found that regions in the brain that regulate appetite became active when people consumed glucose, but remained inactive when they ingested fructose. When those regions become active, they release hormones that produce feelings of satiety (fullness) - in other words, the hormones tell you to stop eating.

5. Lower rates of smoking (smoking suppresses appetite).

 

According to the National Institutes of Health (NIH) "Not everyone gains weight when they stop smoking. Among people who do, the average weight gain is between 6 and 8 pounds. Roughly 10 percent of people who stop smoking gain a large amount of weight - 30 pounds or more."

6. Medications that make patients put on weight.

 

According to an article in Annals of Pharmacotherapy, some medications cause weight gain. "Clinically significant weight gain is associated with some commonly prescribed medicines. There is wide interindividual variation in response and variation of the degree of weight gain within drug classes. Where possible, alternative therapy should be selected, especially for individuals predisposed to overweight and obesity." (The Annals of Pharmacotherapy: Vol. 39, No. 12, pp. 2046-2054. DOI 10.1345/aph.1G33)

 

7. Is obesity self-perpetuating?

 

The longer a person is overweight, the harder it becomes for them to lose weight. Many have wondered whether obesity itself becomes a permanent state, i.e. does obesity promote obesity?. Researchers from the University of Michigan and the National Council of Science and Technology (COINCET) in Argentina, reported in the Journal of Clinical Investigation that in animal experiments, obesity seems to become a self-perpetuating state.

They found that the “normal” body weight of mice that become obese starts going up; their bodies’ perception of normal weight becomes a heavier than before, regardless of whether they are made to go on diets which had made them lose weight.

Senior author, Malcolm J. Low, M.D., Ph.D., said "Our model demonstrates that obesity is in part a self-perpetuating disorder and the results further emphasize the importance of early intervention in childhood to try to prevent the condition whose effects can last a lifetime. Our new animal model will be used in pinpointing the reasons why most adults find it exceedingly difficult to maintain meaningful weight loss from dieting and exercise alone."

Obesity treatments have two objectives:

1. To achieve a healthy weight.
2. To maintain that healthy weight.

 

People who are obese are often discouraged because they think they have to lose a lot of weight before any benefits are experienced. This is not true. Any obese person who loses just five to ten per cent of their body weight will have significant improvement in health - this would mean between 12-25 pounds for an obese person who weighs 250 pounds.

It is important for patients to realize that a small drop in weight is a good start and a great achievement. Experts have found that obese people who lose weight slowly and constantly, say one or two pounds each week, are more successful in keeping their weight down when they have reached their target weight.

According to the Mayo Clinic, successful and permanent weight loss is best achieved as a result of increased physical activity, changing how and when you eat, and modifying your behavior. Some patients may be prescribed medication, while others might undergo weight-loss surgery.

Dietary changes

The Mayo Clinic advises obese people to reduce their total daily calorie intake and to consume more fruits, vegetables and whole grains. It is important that your diet is varied - you still need to feed yourself, and should continue to enjoy the tastes of different foods. The consumption of sugar, certain refined carbohydrates and some fats should be reduced significantly.

Ideally, you should work with your doctor, a dietician, and/or a well-known weight-loss program.

Trying to lose weight quickly by crash-dieting carries the following risks:

• You may develop health problems
• You will probably experience vitamin deficiencies
• You chances of failure are significantly higher

 

People who are seriously obese may be prescribed a very low calorie liquid diet. These must be done with a health care professional.

Physical activity


The more you move your body the more calories you burn. To lose a kilogram of fat you need to burn 8,000 calories (1 pound of fat = 3,500 calories). Walking briskly is a good way to start increasing your physical activity if you are obese. Combining increased physical activity with a good diet will significantly increase your chances of losing weight successfully and permanently!

Try to find activities which you can fit into your daily routine. Anything that becomes part of your daily life, weaved into your existing lifestyle, is more likely to become a long-term habit. If you use an elevator, try getting off one or two floors before your destination and walking the rest. You could try the same when driving your car or taking any form of public transport - get off earlier and walk that bit more.

If any of your regular shops are within walking distance, try leaving your car at home. Several surveys indicated that the majority of urban car trips outside the rush hours are less than a mile long - we can all walk a mile, and should!

If you are very obese, are unfit, or have some health problems, make sure you check with a health care professional before increasing your physical activity.

Prescription medications for losing weight

Prescription medications should really only be considered as a last resort. If the patient finds it extremely hard to shed the pounds, or if his obesity has reached such a point as to significantly undermine his health, then prescription drugs may become an option.

According to the Mayo Clinic prescription medications should only be considered if:

• Other strategies to lose weight have failed
• The patient’s BMI is over 27 and he also has diabetes, hypertension, or sleep apnea.
• The patient’s BMI is over 30

 

There are two approved drugs a physician may consider, Sibutramine (Meridia in USA/Canada, Reductil in Europe and much of the world) or Orlistat (Xenical). Bear in mind that as soon as you stop taking these drugs the overweight problem generally comes back - they have to be taken indefinitely. Some patients may not respond to these drugs, while others may find their beneficial effects may lessen somewhat after a few months.

Weight loss surgery (bariatric surgery)

Weight loss surgery (WLS) is also known as Bariatric Surgery. It comes from the Greek work baros, which means weight.

WLS is a development of cancer/ulcer operations that consisted of removing part of a patient’s stomach or small intestine. Those cancer/ulcer patients subsequently lost weight after surgery. Doctors decided the procedure might be beneficial for morbidly obese patients.

In 2008 about 220,000 bariatric operations were carried out in the USA (American Society for Bariatric Surgery). As obesity levels in America and many other parts of the world grow, so does the number of bariatric procedures. About 15 million people in the U.S. have morbid obesity; only 1% of the clinically eligible population is being treated for morbid obesity through bariatric surgery. According to the American Society for Bariatric Surgery, the average female surgery patient weighs about 300 pounds.

The American Society for Bariatric and Metabolic Surgery says that Bariatric surgery can improve or resolve more than 30 obesity-related conditions, including type 2 diabetes, heart disease, sleep apnea, hypertension and high cholesterol .

Basically, bariatric surgery alters your stomach or small intestine so that you are unable to consume much food in one sitting. This reduces the total number of calories you consume each day, thus helping to lose weight.

There are two types of bariatric surgeries:

 

• Restrictive procedures - These make your stomach smaller. The surgeon may use a gastric band, staples, or both. After the operation the patient cannot consume more than about one cup of food during each sitting, significantly reducing his food intake. Over time, some patients’ stomachs may stretch and they are gradually able to consumer larger quantities.

Researchers from Monash University in Melbourne, Australia, reported in the journal Annals of Surgery that laparoscopic adjustable gastric banding (lap banding) was found to be a successful long-term solution to obesity after carrying out a 15-year follow-up on obese patients.

• Malabsorptive procedures - Parts of the digestive system, especially the first part of the small intestine (duodenum) or the mid-section (jejunum), are bypassed. Doctors may also reduce the size of the stomach. This procedure is generally more effective than restrictive procedures. However, the patient has a higher risk of experiencing vitamin/mineral deficiencies because overall absorption is reduced.

 

Combining two hormones into one molecule, a possible obesity treatment

Scientists from Indiana University managed to combine GLP-1, a digestive hormone, with the hormone estrogen with promising obesity treatment results in an animal experiment.

They published their findings in the journal Nature Medicine (November 2012).

The authors wrote "We find that combining the hormones as a single molecule dramatically enhanced their efficacy and their safety. The combination improves the ability to lower body weight and the ability to manage glucose, and it does so without showing the hallmark toxicities associated with estrogen."

The scientists believe that the combination of nuclear hormones and other peptides as substances for therapeutic usage is a significant and promising opportunity for research.

Making white cells more like brown cells

Scientists from the Perelman School of Medicine found a protein switch that determines whether precursor fat cells become white or brown fat cells.

• Brown fat cells burn calories, they produce heat
• White fat cells store calories in the all-too-obvious deposits that plague the growing numbers of obese people

 

They wonder whether it might be possible to reprogram white fat cells to become a little more like brown fat cells.

Lead researcher, Patrick Seale, explained that brown fat cells, being the ones that produce heat in the body, are protective against obesity as well as type 2 diabetes.

Overweight and Obesity - Health Consequences

The primary concern of overweight and obesity is one of health and not appearance. Obesity is a serious disease with serious health risks.

Obesity Health Risks - Premature Death

• An estimated 300,000 deaths per year may be attributable to obesity.

• The risk of death rises with increasing weight.

• Even moderate weight excess (10 to 20 pounds for a person of average height) increases the risk of death, particularly among adults aged 30 to 64 years.

• Individuals who are obese (BMI > 30) have a 50 to 100% increased risk of premature death from all causes, compared to individuals with a healthy weight.

Obesity Health Risks - Heart Disease

• The incidence of heart disease (heart attack, congestive heart failure, sudden cardiac death, angina or chest pain, and abnormal heart rhythm) is increased in persons who are overweight or obese (BMI > 25).

• High blood pressure is twice as common in adults who are obese than in those who are at a healthy weight.

• Obesity is associated with elevated triglycerides (blood fat) and decreased HDL cholesterol ("good cholesterol").

Obesity Health Risks - Diabetes

• A weight gain of 11 to 18 pounds increases a person’s risk of developing type 2 diabetes to twice that of individuals who have not gained weight.

• Over 80% of people with diabetes are overweight or obese.

 

Obesity Health Risks - Cancer

• Overweight and obesity are associated with an increased risk for some types of cancer including endometrial (cancer of the lining of the uterus), colon, gall bladder, prostate, kidney, and postmenopausal breast cancer.

• Women gaining more than 20 pounds from age 18 to midlife double their risk of postmenopausal breast cancer, compared to women whose weight remains stable.

Obesity Health Risks - Breathing Problems

• Sleep apnea (interrupted breathing while sleeping) is more common in obese persons.

• Obesity is associated with a higher prevalence of asthma.

 

Obesity Health Risks - Arthritis

• For every 2-pound increase in weight, the risk of arthritis increases by 9 to 13%.

• Symptoms of arthritis can improve with weight loss.

Obesity Health Risks - Reproductive Complications & Complications of Pregnancy

• Obesity during pregnancy is associated with increased risk of death in both the baby and the mother and increases the risk of maternal high blood pressure by 10 times.

• In addition to many other complications, women who are obese during pregnancy are more likely to have gestational diabetes and problems with labor and delivery.

• Infants born to women who are obese during pregnancy are more likely to be high birth weight and, therefore, may face a higher rate of Cesarean section delivery and low blood sugar (which can be associated with brain damage and seizures).

• Obesity during pregnancy is associated with an increased risk of birth defects, particularly neural tube defects, such as spinal bifida.

• Obesity in premenopausal women is associated with irregular menstrual cycles and infertility.

Obesity Health Risks - Additional Health Consequences

• Overweight and obesity are associated with increased risks of gall bladder disease, incontinence, increased surgical risk, and depression.

• Obesity can affect the quality of life through limited mobility and decreased physical endurance as well as through social, academic, and job discrimination.

Obesity Health Risks - Children & Adolescents

• Risk factors for heart disease, such as high cholesterol and high blood pressure, occur with increased frequency in overweight children and adolescents compared to those with a healthy weight.

• Type 2 diabetes, previously considered an adult disease, has increased dramatically in children and adolescents. Overweight and obesity are closely linked to type 2 diabetes.

• Overweight adolescents have a 70% chance of becoming overweight or obese adults. This increases to 80% if one or more parent is overweight or obese.

• The most immediate consequence of overweight, as perceived by children

Source: US Surgeon General (2002)