Weight Loss and Obesity

Overweight and obesity

According to the World Health Organization (WHO), being overweight means that the ratio of your weight to the height of your body, a proportion that is called the Body Mass Index (BMI), is at least 25.1 Being obese, which in commonly referred to as being the same as being very overweight, actually means that your BMI is at least 30.

The following chart shows the WHO’s definitions for different categories of being overweight. A disadvantage of the BMI, however, is that it does not separate weight from fat versus weight from muscle.1 For example, if you are very muscular you may have a higher BMI for your height and still be healthy.


Body Mass Index (BMI) (kg/m2)

Having a normal weight (considered healthy) 18.5 – 25
Being overweight 25 – 30
Having moderate (Class I) obesity 30 – 35
Having severe (Class II) obesity 35 – 40
Having very severe (Class III) obesity More than 40

Another way to determine whether you have too much fat in your body is to measure your waist.

In 2014, an estimated 68% of people in the UK were overweight or obese.1 Approximately one out of every four adults in the UK is considered obese.2

Weight is not just a consideration for beauty and your healthy self-pride. If you are a woman whose waist is at least 80 cm, you may develop weight-related problems with your health.2 Being overweight or obese can cause everyday problems with your health, including:1,2:

  • Feeling out of breath
  • Snoring during sleep
  • Increase in sweating
  • Fatigue
  • Trouble doing physical activities
  • Pain in the back
  • Pain in the joints
  • Avoidance of social situations
  • Depression

Importantly, being overweight or obese contributes to your risk of the following serious conditions:1,2

  • Type 2 diabetes
  • High blood pressure
  • Metabolic syndrome, which is the combination of diabetes, high blood pressure and obesity
  • High levels of cholesterol in the blood
  • Narrowing of the arteries (a condition called atherosclerosis)
  • Heart attacks
  • Stroke
  • Cancer of the breast, uterus (womb) and the bowel
  • Asthma
  • Arthritis
  • Gastro-oesophageal reflux disease (GORD), in which acid from the stomach moves upward into the esophagus
  • Gallstones
  • Problems with your liver
  • Problems with your kidneys
  • Decreased fertility
  • Complications of pregnancy, such as gestational diabetes or pre-eclampsia
  • Sleep apnoea, a situation in which your breathing stops for a short period of time while you sleep. The condition can cause you to be sleepy during the day, which could cause accidents if you drive.

In fact, being overweight or obese is the fifth most major cause of death in the world.1 In Europe, weighing too much or being obese contributes to about 1 in every 13 deaths.2 On a personal level, it has been estimated that being obese decreases a person’s lifespan by approximately 3 to 10 years.

Internationally it is estimated that being overweight or obese is responsible for:1, 2

  • 44% of diabetes
  • 23% of heart conditions involving the arterial blood flow to the heart being decreased, due to the structure of the arteries
  • Between 7% and 41% of certain cancers, including cancer of the breast and cancer of the bowel

Fortunately, being overweight or obese is preventable and treatable. Being the right weight for your body helps to keep you healthy and provides a good quality of life. Even a modest weight loss of 3% that is maintained for the rest of your life can decrease your risk of serious health problems related to being overweight or obese.2

How do I lose weight?

Weight loss generally is achieved by a combination of reduction in calories from food and an increase in physical exercise. The reason is that exercise uses calories. So, if you sufficiently decrease the calories you eat and sufficiently increase the calories you use, your body will break down its fat tissue first in order to have enough energy to carry out its normal functions.

For a healthy diet, you can

  • Decrease your intake of fat and sugar
  • Increase your intake of vegetables and fruits
  • Increase your intake of non-meat sources of proteins, such as nuts, whole grains, beans and eggs
  • Include some starches, such as potatoes, rice, bread and pasta
  • Include some milk and other dairy foods
  • Include some animal sources of protein, such as fish, chicken and meat
  • Decrease your intake of salt
  • Eat your meals slowly, so that you may become full while you are eating

Your nutritionist, dietician, doctor, or nurse can help you plan a reduced calorie diet. For motivation and support from your peers you can join a weight loss group in your area. If overeating is a serious problem for you, you might consider seeing a psychologist to discuss your personal issues around foods and meals.

In contemporary society many people lead sedentary lives, in which they sit too long at their desks, at home and in cars. For adults, an exercise program of 2.5 to 5 hours per week (or about 20 to 45 minutes daily) is recommended.1, 2 Choose whatever physical exercise you enjoy that you can participate in regularly. Walking, jogging, cycling, tennis, swimming, dancing and running are good for your weight and overall health.

Recognize that losing weight requires you to be committed and takes a while. Set realistic goals of weight loss and you can praise yourself as you reach your milestones.

After a person loses weight, the body requires fewer calories to maintain the lower weight. So, if you continue to consume the same number of calories you did to lose the weight you may regain some weight. Ways to avoid the regaining of weight is to decrease your caloric intake slightly and increase your level of exercise to an hour daily.

A minority of people are overweight or obese because they have a thyroid gland that produces insufficient amounts of the thyroid hormone, due to a condition known as hypothyroidism. People who are hypothyroid can take thyroid hormone prescribed by their doctor.

How can I stimulate weight loss medically?

Medical approaches to weight loss for people who are overweight or obese include:

  • Blockers of fat absorption, which are available by prescription or over-the-counter.
  • Appetite suppressants, which are available by prescription only from private physicians who practice in slimming clinics.
  • Weight loss (bariatric) surgery involves surgically making the stomach smaller, so that it can accept less food) for people who are very obese.

In the UK, bariatric surgery generally is restricted to people who have either a BMI of at least 40 or a BMI between 30 and 40 and another serious weight-related condition (e.g., high blood pressure or diagnosis of type 2 diabetes within the last decade) and in either case, have failed a combination of diet, exercise and medication.

For people whose BMI is at least 50, bariatric surgery may be performed prior to diet, exercise, and medication.

To be a candidate for bariatric surgery, the person has to be healthy enough to undergo anaesthesia and surgery and commits to management of weight loss and long-term follow-up. The goals of the surgery are to have you digest less food and feel fuller faster, resulting in weight loss.

Techniques for bariatric surgery include, but are not limited to:

  • Gastric banding, in which a band is placed to seal off part of the stomach.
  • Gastric bypass, in which your digestive system mostly is routed to the duodenum (rather than the stomach first) and the intestines
  • Sleeve gastrectomy, in which part of the stomach is surgically removed

The gastric banding method usually results in half the excessive body weight being lost in a gradual process that can take two years. The gastric bypass method usually results in two-thirds of the excessive body weight being lost in a gradual process that can take two years. Patients may desire cosmetic surgery later to remove loose folds of skin that occur after the weight is lost.

Risks of bariatric surgery are:

  • Pain
  • Bleeding
  • Blood clots in the legs
  • Pulmonary embolism, which is a piece of a blood clot that lodges in a blood vessel in the lungs
  • Infection

Having high blood pressure or a BMI greater than 50 raises the risk of complications from bariatric surgery. An estimated 1 in 1000 patients die in hospital following bariatric surgery.

Recovery time can be long with the types of gastric surgery that are performed in hospital.

What are the benefits of weight loss?

Benefits of weight loss for a person who is overweight are that:

  • You will be more satisfied with the look of your body
  • You will have more energy
  • You will reduce the risk of serious conditions

What medication options are available for weight loss?

Two blockers of fat absorption are available in the UK. Xenical is a prescription medication containing orlistat. Orlistat prevents the action of lipase, an enzyme that breaks down fat. When lipase is blocked during the digestive process, fat from food cannot be absorbed by the body and cannot be turned into fat tissue. Orlistat blocks approximately one-third of the fat in food from being absorbed by your body.

Xenical is prescribed to women who have previously tried to lose weight through diet and exercise, and have a BMI of at least 30, or a BMI of at least 28 and other weight-related problems, such as type 2 diabetes or high blood pressure. If you are prescribed Xenical, you must eat a low-fat diet and continue you’re your exercise programme. But, Xenical is not recommended for women who are pregnant or breastfeeding an infant.

Take Xenical every day, according to your doctor’s instructions. The following is meant as a general guide for taking Xenical:

  • One capsule of Xenical is taken with every one of your three main meals that contain fat every day.
  • You can take Xenical one hour before, during, or one hour after eating a main meal.
  • If you skip a meal or eat a meal that contains no fat, you do not have to take a capsule of Xenical with that meal.

Women with type 2 diabetes, high blood pressure, or a kidney condition may need to take a different dose of Xenical. Your doctor will determine the appropriate dose of Xenical for you and the suitable weight loss goal for your medical condition.

Typically, Xenical begins to affect how your body digests fat within one to two days. If you have successfully lost 5% of your body weight after three months of taking Xenical, your doctor will most likely stop your prescription. If by three months of taking Xenical, you have lost weight, but the loss is less than 5% of your body weight, your doctor may continue your prescription for up to a year. If you have not lost weight by three months of taking Xenical your doctor probably will stop your prescription.

Possible side effects of Xenical, especially if you have not reduced your fat intake sufficiently include:2

  • Bowel movements that are fatty or oily
  • An oily discharge from the rectum
  • More frequent bowel movements
  • More urgent need to have a bowel movement
  • Gas (wind, which also is called flatulence)
  • Pain in the stomach
  • Headaches
  • Infections (such as a cold) of the upper respiratory tract

If you are taking Xenical and an oral contraceptive and experience diarrhoea, you may need to use an additional method of contraception, such as condoms. The reason is that the diarrhoea may interfere with the oral contraceptive being absorbed by your body.

Another option to Xenical is Alli, an over-the-counter medication containing a lower amount of orlistat.

In addition, prescriptions for appetite suppressants may be available if you consult with private physicians who practice in slimming clinics. These medications include phentermine and diethylproprion.


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