If you are obese and you wish to lose weight, you should see your GP.
They will recommend:
- what type of diet you should be following
- how much exercise you will need to do
- whether you need further testing or treatments for obesity-related conditions
- whether you need treatment for an underlying cause of obesity such as polycystic ovary syndrome
Your GP may refer you to other services, such as local weight loss groups. These could be provided by the NHS, or may be commercial services you pay for.
If it’s appropriate, your GP may recommend exercise on prescription, where you are referred to a local active health team for a number of sessions, under the supervision of a qualified trainer. Depending on where you live, the exercise programme may be free or at a reduced cost.
Read more about how your GP can help you lose weight.
While there is no single rule, most obese people are told they have to reduce their energy intake from their diet by 600 calories a day.
The best way to achieve this is to swap unhealthy and high energy food choices such as fast food, processed food and sugary drinks (including alcohol) for healthier choices.
A healthy diet should consist of :
Also avoid food that contains high levels of salt as this can raise your blood pressure, which can be dangerous in already obese people – read more about the dangers of salt.
You will also need to check calorie information for each type of food and drink you consume to make sure you do not go over your daily limit – read more about calorie counting.
Some restaurants, cafes and fast-food outlets provide calorie information per portion, but providing this information is not compulsory. Be careful - some foods can quickly take you over the limit, such as burgers, fried chicken and ethnic foods such as curries or Chinese dishes.
Avoid fad diets
You should avoid fad diets that recommend unsafe practices such as fasting (going without food for long periods of time) or cutting out entire food groups such as meat, fish, wheat or dairy products.
These are not sustainable, can make you feel ill, and may cause unpleasant side effects such as bad breath, diarrhoea and headaches. Read more about the truth behind fad diets.
This is not to say that all commercial diet programmes are unsafe. Many are based on sound medical and scientific principles and can work well in some people. A responsible diet programme should:
- educate you about issues such as portion size, making changes to long-term behaviour and healthy eating
- not be overly restrictive in terms of the type of food you can eat
- be based on achieving gradual sustainable weight loss rather short-term rapid weight loss, which is unlikely to last
Read the NHS Choices review of the ‘Top 10 Diets’
Very low calorie diet
A very low calorie diet (VLCD) is where you consume less than 1,000 calories a day. An example of a VLCD would be:
- a bowl of cornflakes for breakfast
- a single jaffa cake as a mid-morning snack
- a chicken salad sandwich for lunch
- a low calorie lasagne for an evening meal
- a pear for an after-dinner treat
This plan also assumes that you will be drinking water or diet drinks throughout the day as most other popular drinks such as tea and coffee contain calories.
Remember excessive amounts of fizzy diet drinks can damage your teeth; they may not contain sugar, but they do contain high levels of certain acids.
While a VLCD can be an effective method of losing weight for some obese people, is it not a suitable or safe method for everyone. It would usually only be recommended if rapid weight loss was required to reduce the risk of an obesity-related complication, such as heart disease, or if you have failed to lose weight despite conventional treatment.
You should only ever undertake a VLCD under the supervision of a suitably qualified healthcare professional.
For more information on diet and weight loss see:
Reducing the amount of calories in your diet will stop you putting on more weight. But if you want to lose weight, you will have to combine a calorie-controlled diet with regular exercise.
Your GP or weight loss adviser will be able to provide an exercise plan suited to your circumstances, which will probably recommend so many hours of moderate intensity physical activity a week.
Moderate intensity physical activity is any activity that increases your heart and breathing rate and may make you sweat, but you are still able to hold a normal conversation.
- fast walking
- using a step-trainer or similar at gym
Chose physical activities that you enjoy, as you are more likely to continue doing them.
You should aim to start gradually – possibly 15 to 20 minutes of exercise five times a day – and then build on it.
For more information on exercise see:
Over 120 different types of anti-obesity medication have been tested in clinical trials but only one has proved to be both safe and effective. This medication is called orlistat.
Orlistat works by blocking the action of a protein used to digest fat. The undigested fat is not absorbed into your body, and is passed out with your faeces (stools).
Orlistat will stop around one third of the fat from the food you eat from being digested.
This will help you avoid gaining weight, but it will not necessarily cause you to lose weight. So it is still important to stick to your recommended diet and exercise plan.
One orlistat capsule is taken with each main meal (a maximum of three capsules a day). You can take the capsule either before, during, or up to one hour after each meal.
If you miss a meal, or the meal does not contain any fat, you may not need to take the orlistat capsule. Your GP should explain this to you, or you can check the patient information leaflet that comes with your medication.
You have to have made significant effort to lose weight through diet, exercise or changing your lifestyle before taking orlistat. Even then, orlistat is only prescribed if you are on a low calorie diet and you have:
- a body mass index (BMI) of 28 or more, and other conditions related to weight, such as high blood pressure (hypertension), or
- a BMI of 30 or more
Treatment with orlistat must be combined with a low fat diet and other weight loss strategies, such as doing more exercise. If you are prescribed orlistat, you will also be offered advice and support about diet, exercise and making lifestyle changes.
Treatment with orlistat should only continue beyond three months if you have lost 5% of your body weight. Orlistat usually starts to affect how you digest fat within 1-2 days. If orlistat has not worked after three months, it is unlikely to be an effective treatment for you.
If you have type 2 diabetes (a condition caused by too much glucose in the blood), it may take you longer to lose weight using orlistat. Your target weight loss after three months may therefore be slightly lower.
If orlistat is successful after three months, your prescription may be continued for up to a year. After that, your GP will review your condition and decide whether you should continue with orlistat or not.
Side effects of orlistat include:
Side effects are much less likely if you stick to a low fat diet.
Women taking an oral contraceptive pill are advised to use an additional method of contraception, such as a condom, if they experience severe diarrhoea while taking orlistat.
This is because if you have diarrhoea, your contraceptive pill may not be absorbed by your body, and so may not be effective.
Orlistat is not suitable for pregnant or breastfeeding women.
Treating obesity in children
Treating obesity in children is based on much the same principles as treating obesity in adults: combining a calorie controlled diet with regular exercise.
The amount of calories your child should eat every day will depend on their age and height. Your GP should advise on a recommended daily limit.
It is recommended all children get at least one hour of moderately intense exercise a week, such as running, playing football or netball.
You should restrict sedentary activities such as watching television or playing computer games to less than two hours a day (14 hours a week).
It may be better to gradually introduce these changes to your child’s behaviour then try to get them to ‘change overnight’.
Referral to a specialist in treating childhood obesity may be recommended if:
- your child develops an obesity-related complication such as high blood pressure, sleep apnoea (interrupted breathing during sleep) and depression
- it is thought there is an underlying medical condition causing the obesity such as a hormonal condition
The use of orlistat in children is only recommended in exceptional circumstances such as if a child is severely obese and also has an obesity-related complication.
For more information on diet and exercise in children see: