Obesity is a widely-used term for a person who is very overweight, holding excess body fat.

Recent studies are leading some experts to believe that obesity can result in more health risks than smoking. In 2014, WebMD estimated that up to 24% of UK men and 26% of UK women fell into the obese category. Childhood obesity is now a common problem in the UK, with around one in five children aged 10 being an unhealthy weight.

  • Obesity is an excess of total body fat weighing over 20 per cent of the person’s ideal weight.
  • A person is classed as obese if their BMI is between 30 and 39.9.
  • A result above 40 is categorised as severely obese.

This factsheet will explore questions like ‘Am I overweight?’ and ‘Has my weight put me at risk?’. We will also discover the causes of obesity, what treatment options are available, how to combat childhood obesity and how a nutritionist can help.

Am I overweight?

These days there are a number of ways in which we can measure a person’s health and weight. The most common method to classify a person’s weight is through calculating their body mass index (BMI). While your BMI can measure whether you are a healthy weight in relation to your height, it does not consider muscle mass.

  Body mass index (BMI)
Underweight below 18.5
Healthy weight 18.5 to 24.9
Overweight 25 to 29.9
Obese 30 to 39.9
Severely obese 40 or above

Another measure of weight is waist circumference – carrying excess weight on the waist as opposed to on the hips and thighs are at a greater risk of developing weight-related health problems. Once you have your measurement you can use the following rules to help interpret them:

  Increased risk Even higher risk
Men A waist measurement of 94cm or more. A waist measurement of 102cm or more.
Women A waist measurement of 80cm or more. A waist measurement of 88cm or more.

Severely obese

When an individual finds their body mass index is greater than 39.9, or they are carrying an excess weight of 100 pounds or more over their ideal body weight, they are classified as being affected by severe obesity. If a person is already suffering with a weight-related illness, such as diabetes or hypertension and their BMI falls over 35, they may also be classified as severely obese.

Is my weight already putting me at risk?

If you have concerns that you may be overweight or obese, and this has put your health at risk, do seek advice from a GP. They may start asking about any symptoms you may have experienced and tests may be carried out in order to rule out any potential issues.

Taking steps to promote healthy weight-loss is important in relation to the obvious physical changes, but also in reducing the risk of developing severe health conditions. Some common weight-related conditions include:

  • type 2 diabetes
  • high blood pressure
  • cholesterol levels
  • thyroid or liver problems
  • coronary heart disease.

In addition to the physical issues caused by excess weight, many people can be affected on a psychological level. Self-image plays a vital role in our confidence and self-esteem levels, as well as our mental well-being. It is not uncommon for individuals who are overweight or obese to develop mental health issues.

Childhood obesity

The World Health Organisation (WHO) has reported childhood obesity to be one of the most serious challenges for public health this century. WHO regard obese children and adolescents to be living with an increased risk of developing weight-related health conditions. The eating habits and lack of activity will often lead to weight problems in adulthood. The National Child Measurement Programme measure the height and weight of an estimated one million children every year in order to find out more about the epidemic. The most recent figures for 2013/14 showed 19% of children aged 10 and 11 were classed as obese and a further 14% were overweight, while over a fifth of children aged four to five were overweight.

Before making any changes to your child’s diet, do make sure to discuss this with your doctor. There may be other conditions affecting their weight that need to be accounted for. However, if their dietary habits are a concern, a nutritionist may be of help. They will be able to support and advise you on what changes need to be made in order for them to follow a calorie-controlled diet and live an active lifestyle.

Obesity causes

Though there are many factors that can affect a person’s weight - it does not develop overnight. Consuming high amounts of fat and sugar but not burning enough energy through physical activity will in time result in the body storing it as excess fat.

Your metabolic rate is the amount of energy or calories your body needs to burn in order to function normally. There is a common misconception that overweight and obese individuals have a low metabolic rate, when in fact more often than not, obese individuals have a normal to high metabolic rate - this is because the body uses more energy to carry the excess weight.

Poor diet

One of the primary reasons people gain weight is a result of their diet. When we are eating food our body sends signals to indicate fullness, this sensation can be ignored if we are eating something we enjoy. A recent study found that an area of our brain linked to addiction and reward, lights up when we are faced with carb-rich, fatty foods. Eating what we think to be ‘rewards’ can be harmful to our health, for example:

  • eating large amounts of processed or fast food
  • drinking an excess of alcohol
  • eating larger portions
  • drinking fizzy drinks
  • comfort eating.

These foods in excess can result in rapid weight gain; products with high sugar and fat content can result in an increased risk of developing health problems later in life. A balanced, calorie-controlled diet consisting of fresh fruits, vegetables and regular exercise can help reduce the risks and promote healthy weight-loss.

Lack of physical activity

The World Health Organisation’s Global Recommendations on Physical Activity for Health suggest that adults between the ages of 18 and 64 should do at least 150 minutes of moderate intensity physical activity per week. It may sound like a lot, but think of it in terms of 30 minutes a day, for five days. Regular exercise is manageable, though the unfortunate reality is that many people are either 'too busy' or unwilling to adopt it into their lifestyle.

Physical activity not only helps our body burn off any excess energy which may be stored as fat, it is also necessary to keep our bodies in optimum condition.

Environmental and genetic factors

Though no evidence has been found linking genetics to obesity, it has been revealed that those with either one or both parents classed as overweight, stand a higher risk of becoming obese themselves. This could be due to environment, children may be picking up unhealthy eating habits from their parents; although in some cases, it is thought that certain individuals do inherit a tendency to overeat and lack appetite control. It is important to consider how your eating habits can affect those around you, it is thought the dietary habits of parents may be contributing to childhood obesity.

Our brain sends a signal when our body is sensing fullness, but many people do not have the appetite control to acknowledge when to stop.

Medical problems

There are very few individuals who can attribute their weight to a medical cause. Polycystic ovary syndrome and an underactive thyroid can result in weight gain for women - some individuals may also find that side-effects of medication can often cause weight fluctuation.

Obesity awareness infographic

Obesity risks

If you are overweight or obese, you may have an increased risk developing a range of weight-related health conditions. In addition to this, carrying an excess of fat can make it difficult to complete basic activities that otherwise should be easy. Side effects that can occur include:

  • excess sweating
  • joint pain
  • skin irritations
  • lack of energy
  • breathing problems.

Depending on the severity, obesity can reduce a person’s life expectancy by up to 10 years. Individuals falling into the overweight or obese category are at an increased risk of developing the following health concerns:

Type 2 diabetes

This condition is caused by fat, liver and muscle cells not responding to insulin normally, this means the cells are not able to absorb the blood sugar to store for energy. When the sugar is unable to enter the cells this results in a large build up of sugar in the blood, an effect known as hyperglycaemia. High blood sugar can cause the pancreas to produce more insulin, but often this is not enough to meet the demands of the body.

While some individuals will display no obvious symptoms, others can experience blurred vision, erectile dysfunction, increased urination, fatigue and an increased thirst and appetite. Type 2 diabetes is more common among overweight and obese individuals - the fat prohibits the body’s ability to use the insulin produced.

High blood pressure

Individuals who are overweight or obese carry excess body fat, this means there is a high number of fatty molecules in the blood vessels. Too much fat can affect the blood vessels, constricting the blood flow and putting strain on the heart. High blood pressure is a result of the blood moving through the arteries at a higher pressure than normal. An estimated 30% of the UK public suffer high blood pressure without knowing. Nicknamed ‘the silent killer’, high blood pressure can increase risk of heart attack or stroke when left untreated.

Sleep apnoea

A common result of obesity, this condition is characterised by the walls of throat coming together during sleep and blocking the airway. The breathing of the individual stops for a period of time, the brain will then recognise the oxygen deficiency and send a call to wake up. This is common in obesity as extreme weight gain can lead to the airways narrowing. Weight-loss is a way to reduce the risk of suffering sleep apnoea.

Coronary heart disease

Responsible for over 70,000 deaths in the UK every year, it is estimated to affect one in six men and one in 10 women. In 2014, it was thought that up to 2.3 million people in the UK were living with the condition, while up to two million were suffering from angina - a common symptom of CHD. Although varied, the most common symptoms of coronary heart disease are:

  • angina (chest pain)
  • heart attacks
  • heart failure.

Other conditions

Obesity has been linked to the development of conditions including various cancers, fatty liver, fertility issues, gallstones, high cholesterol, pregnancy issues and stress incontinence.

In addition to these physical health risks, obese individuals are also prone to developing psychological problems. Self-esteem, self-confidence and self-image often suffer when individuals gain weight. Commonly, overweight and obese people can feel hopeless, angry and isolated. These feelings can result in irritation, comfort eating and can lead to serious mental health concerns, such as anxiety and depression.

Obesity treatment

If you are committed to making a change and losing the excess weight, you first have to accept that it takes time and patience. While the initial weeks often see rapid results, a successful long-term weight-loss requires a change in diet and an increase in physical activity.

It is important to consider the following when adopting a change in lifestyle:

  • Are you motivated?
  • Is your goal realistic?
  • Are you prepared to track your progress?

You may benefit from getting support and advice from a qualified nutritionist, they will help create a balanced diet plan tailored to you and advise the best changes to make to your daily routine. Eating a balanced, calorie-controlled diet is the best way to treat obesity; exercising regularly will improve your overall health and enhance the weight-loss process. For individuals that have tried and failed to maintain a successful weight-loss, or are suffering serious weight-related conditions, an effective treatment is bariatric surgery.

Bariatric surgery is the term used to describe invasive operations with intent to induce weight-loss. The National Institute for Health and Care Excellence have recommended that patients with a BMI of 50 or above are first in line for bariatric surgery.

The forms of bariatric surgery available include:

  • gastric bypass
  • intragastric balloon
  • laparoscopic adjustable gastric banding
  • sleeve gastrectomy.

If you want to find out more about the different forms of bariatric surgery, please look at our weight-loss page.

How can a nutritionist help you?

A nutritionist can support and help you lose weight whilst maintaining it long-term. A nutritionist will often begin by discussing your dietary habits and activity levels, your lifestyle and emotional well-being in order to distinguish what may be affecting your eating habits.

Usually, a nutritionist will begin by compiling a detailed case history of your diet, lifestyle and any health issues. This may include asking you to complete a food diary before the initial consultation in order for them to determine where the problems may lie. The food diary will most likely involve you noting down what you eat, how often and your portion sizes.

At this stage, the nutritionist may ask you to complete some medical tests to ensure your health and well-being. They will discuss with you the issues that may need to be considered within your nutrition programme, these could include special dietary requirements or current or past health conditions. The other points to consider include your physical activity levels, your mental well-being and flexibility.

After the above have been considered, the nutritionist will create a calorie-controlled diet plan and activity programme that are both realistic and achievable. Over time, your progress will be monitored and the nutritionist will be there to offer ongoing support and advice. Extreme lifestyle changes are tough so regular consultations are advised, multiple visits enable you to stay motivated and committed.

Contacting a nutritionist will not only benefit and support the start of your weight-loss journey, they will be there to ensure the changes you have made will be maintained long-term. Throughout your progress, the nutritionist will make adjustments to your plan in order to adapt to your new lifestyle and eventually, you will have reached a point where you feel you can continue your healthy lifestyle without the extra support.

Further help

Related topics

Search for a nutritionist
Would you like to provide feedback on our content?
Tell us what you think

Please note we are unable to provide any personal advice via this feedback form. If you do require further information or advice, please search for a professional to contact them directly.

You appear to have an ad blocker enabled. This can cause issues with our spam prevention tool. If you experience problems, please try disabling the ad blocker until you have submitted the form.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Find a nutritionist dealing with obesity

All therapists are verified professionals.

Related Articles

More articles