Obesity

Obesity is a medical condition in which the body stores so much fat that it increases the risk of other conditions. Obesity can cause health problems.

When do you have obesity?

Obesity means having severe excess weight. This can be calculated using the Body Mass Index (BMI), a number showing the relationship between height and weight. A BMI above 30 is classed as obesity. If you are short and muscular, your BMI may also be higher; this does not necessarily mean you have obesity. Calculate your BMI.

What are the consequences of obesity?

Obesity increases the risk of health problems such as:

• Type 2 diabetes.
• Heart problems.
• High blood pressure.
• Sleep apnoea (not breathing during sleep).
• Certain cancers.
• Shorter life expectancy.
• Problems affecting the feet, ankles, knees, hips and back.
• Reduced stamina.

What causes obesity?

People with obesity generally consume more energy through food than they use through activity. Heredity or genetic predisposition may play a role.

The body needs energy for basic functions such as circulating blood, controlling the brain and operating the organs. This is called the resting metabolism and is expressed in calories. Your basic calorie requirement is the amount needed to get through a day without additional physical exertion.

Daily activities and movement also require energy. Adding this to your basic requirement gives the total number of calories you need each day. If you consume more than this, you take in more energy than you use and may gradually gain weight.

On average, women need 2000 calories per day and men 2500, depending on age and lifestyle. You can calculate your daily calorie requirement.

Heredity
Heredity may play a role. Some people use more energy because they have a faster metabolism. Body composition also matters: muscles use more calories at rest than fatty tissue. Nevertheless, the main problem is often eating too much.

Other causes
In exceptional cases, obesity may be caused by a metabolic disease, medication or a mental health condition.

How does age affect obesity?

Age itself does not cause obesity. However, the resting metabolism slows as we age, so we need fewer calories to maintain basic bodily functions.

Hormones partly determine the resting metabolism. Around the menopause or male menopause, people may report weight gain and difficulty losing weight. It is therefore important to eat less and/or exercise more as we age.

What are the risk factors for obesity?

Too much unhealthy food is the main cause, but many factors increase the risk:

• Eating disorder.
  Disordered eating can disturb the metabolism. Alternating periods of very little food with normal or excessive eating may cause the body to store extra fat.
• Eating too many carbohydrates.
  Excess carbohydrates, especially sugar, may disrupt fat storage.
• Stress.
  Long-term stress can cause cortisol to build up, increasing fat storage and appetite.
• Too little sleep.
  Insufficient sleep can prevent recovery and raise cortisol. Night workers more often have excess weight.
• Hormone-disrupting substances.
  Medication or toxic substances can disrupt the hormone balance.
• Stopping smoking.
  Smoking suppresses appetite and food may taste better after quitting.

What can you do about obesity?

Pay attention to what and how much you eat. Check food labels for calorie content, even on products that appear healthy.

Tips

• Watch your calorie intake.
• Get moving and stay active. Take the stairs instead of the lift and cycle to work, for example.
• Choose an activity you enjoy. You are more likely to keep it up.
• Prevent stress. During stressful periods, plan relaxing activities such as exercise, reading or music.

If you have obesity, it is best to seek help to reduce your weight. A dietitian or nutritionist can help. Trying random diets is not advisable, as the body needs the right nutrients and sufficient energy.

Exercise
Exercise is important for weight loss. A physiotherapist can advise which activity is best for your body and how to prevent injuries when starting. Many physiotherapy practices offer exercise programmes for people with obesity, allowing you to work on your weight in a group under physiotherapist supervision.