What is Obesity?

Obesity is a condition where a person has accumulated a high amount of body fat having a negative effect on their health. Obesity is a chronic condition defined by an excess amount of body fat. Obesity is best defined using Body Mass Index (BMI) which is calculated using a person’s height and weight. A BMI of 18.5-24.9 is considered normal weight, a BMI of 25-29.9 is considered overweight, and a BMI of over 30 is considered obese. 

Read NHS Choices 12 Week Weight Loss Guide 

What are the Causes of Obesity?

• Calories- The average calories which a male needs includes 2500 calories a day to maintain a healthy weight and for a female 2000 calories a day. If people go over the amount of average calories this can lead to obesity especially if you eat too much. A lot of people who aren’t physically active and eat a lot of junk food puts you at a higher risk of obesity due to the fact that a lot of the calories consumed in fat and/or sugary, salty foods ends up being stored in the body as fat.

BMI Diagram

• Poor diet- Eating large amounts of processed or fast food that is high in fat or sugar/ overeating. This leads to weight gain. Drinking too much alcohol is also a risk of obesity due to the fact that alcohol contains a lot of calories, and heavy drinkers are often overweight. Smoking can also cause weight gain. Eating large portions of food is also a risk factor for obesity especially if you are constantly eating. Drinking too many sugary drinks is also a risk factor for obesity such as fizzy drinks and also sugary soft drinks.

• Lack of Physical Activity- This is another important factor related to obesity. If you are not active enough you do not use the energy provided from the food which you consume, and the extra energy consumed is stored in your body as fat. For example relying on cars rather than walking or cycling, watching TV all day, browsing the internet, playing video games. This reduces the amount of times in which people exercise and this is rarely leading to obesity due to inactivity.

• Genetics- If it runs in your family or genes then you are more likely to develop obesity.

• Medications- Such as certain antidepressants, diabetes, hormone medications.

• Psychological factors- For some people emotions influence eating habits. Comfort eating is also another risk factor for obesity as people may feel better if they eat more food with low self-esteem or feeling depressed, boredom, sadness, stress or anger.

• Social Issues- Lack of money to purchase healthy foods or lack of safe places to walk or exercise can increase the risk of obesity.

• Certain diseases such as hypothyroidism, insulin resistance, polycystic ovary syndrome, Cushing’s syndrome are also contributors to obesity.

• Hormones

• Ethnicity/Age

• Childhood weight

CaloriesBad Eating HabitsInactivity

What are the Health Risks associated with Obesity?

• Insulin resistance

• Type 2 Diabetes- The risk of type 2 diabetes increases with the degree and duration of obesity. This is associated with central obesity where a person has excess fat around his/her waist.

• High Blood Pressure- Hypertension is common among obese adults. Weight gain increases blood pressure.

• High Cholesterol

• Stroke- More likely

• Heart Attack- More likely

• Cancer- Obesity has been linked to many different cancers.

• Osteoarthritis (degenerative arthritis of the knees, hips, and lower back)

Type 2 DiabetesCancers related to overweight and obesity

How can you Prevent Obesity?

• Physical activity and exercise helps to burn calories. Exercise is an effective way of preventing obesity combined with a diet and weight loss programme. Regular exercise is an important part of a healthy lifestyle to maintain a healthy weight in the long term. The benefits this has on your weight include improved blood sugar control and increased insulin sensitivity, reduced triglyceride levels and increased good HDL cholesterol levels, lowered blood pressure, reduction in abdominal fat, reduced risk of heart disease, makes you feel good about yourself and your health and well-being.

• Performing around 20-30 minute of moderate exercise five to seven days a week, preferably daily. This can include cycling, walking, jogging, treadmill, stairclimbing machines, swimming etc.

• Start slowly and progress gradually to avoid injury, excessive soreness.

• Ask your doctor for medical advice on how to keep fit by doing the correct exercise to maintain a healthy weight.

• Healthy Dieting- to prevent further weight gain. Eating more nutritious foods that have low energy density which are foods that contain fewer calories per unit weight. For example, fruit and vegetables, lean meat such as beef cuts, cutting off fat from meats such as lamb, fish, grains and beans. You can eat a large amount of celery or carrots without taking in too many calories.

• Eating more complex carbohydrates such as brown rice, whole grain bread, fruits and vegetables. Drink more healthier drinks not fizzy.

• Establish realistic weight loss goals.

• Educate yourself reading food labels seeing what they contain.

Weight Loss GoalsThe Eatwell PlateExercise and Physical Activity


To find out more information about obesity visit http://www.nhs.uk/conditions/Obesity/Pages/Introduction.aspx