People have the right to be involved in discussions and make informed decisions about their care, as described in NICE's information on making decisions about your care.
Making decisions using NICE guidelines explains how we use words to show the strength (or certainty) of our recommendations, and has information about prescribing medicines (including off-label use), professional guidelines, standards and laws (including on consent and mental capacity), and safeguarding.
Health and social care professionals should follow our general guidelines for people delivering care:
Read this guideline alongside:
NICE guidelines on behaviour change: digital and mobile health interventions, behaviour change: individual approaches, eating disorders, and looked after children and young people
Public Health England's Whole systems approach to obesity and weight management interventions: standard evaluation framework
See also the recommendations on physical activity in the section on behavioural overweight and obesity management interventions.
Ensure staff leading supervised physical activity sessions are qualified and insured, for example, a physiotherapist or a practitioner member of the CIMSPA (Chartered Institute for the Management of Sport and Physical Activity). Ensure that people running children's sessions have a paediatric CPR qualification. [2014, amended 2025]
Encourage adults to increase their physical activity even if they do not lose weight as a result, because of the other health benefits it can bring. Encourage them to meet the recommendations in the UK Chief Medical Officers' physical activity guidelines for weekly activity. See NHS advice on treating obesity [2006]
Advise that to prevent obesity, most people may need to do 45 to 60 minutes of moderate-intensity physical activity a day, particularly if they do not reduce their energy intake. Advise people who have lived with obesity and have lost weight that they may need to do 60 to 90 minutes of activity a day to avoid regaining weight. (See NHS advice on treating obesity.) [2006]
Encourage adults to build up to the recommended activity levels for weight maintenance, using a managed approach with agreed goals. Recommend:
activities as part of everyday life, such as brisk walking, gardening or cycling (see NICE's guideline on walking and cycling)
supervised exercise programmes
other activities, such as swimming, aiming to walk a certain number of steps each day, or stair climbing.
Take into account the person's current physical fitness and ability for all activities. Encourage people to also reduce the amount of time they spend inactive, such as leisure-based screen time. [2006]
Encourage children and young people to increase their level of physical activity, even if they do not lose weight as a result, because of the other health benefits physical activity can bring. Encourage them to meet the recommendations in the UK Chief Medical Officers' physical activity guidelines for daily activity, NHS physical activity guidelines for children and young people and the Department of Health and Social Care's physical activity guidelines for disabled children and disabled young people. [2006, amended 2025]
Be aware that children who are already living with overweight or obesity may need to do more than the standard recommended amount of activity. [2006, amended 2014]
Give children the opportunity and support to both include more physical activity in their daily lives (for example, walking, cycling, using the stairs and active play; see also NICE's guideline on walking and cycling) and to do more regular, structured physical activity (for example football, swimming or dancing). Agree the choice of activity with the child, and ensure it is appropriate to the child's interests, ability and confidence and is affordable for the family (see the UK Chief Medical Officers' physical activity guidelines for ideas of free activities). [2006, amended 2025]
Use a flexible and individualised approach to tailor dietary interventions to achieve nutritional balance while reducing energy intake, taking into account:
food preferences (including cultural preferences)
personal circumstances (such as home environment and family finances)
any comorbidities (such as eating disorders or disordered eating, type 1 diabetes, inflammatory bowel disease or non-alcoholic fatty liver disease)
any restrictions in the range of foods they eat (for example because of neurodiversity, sensory problems, or coeliac disease)
that in many cases weight regain may happen. [2025]
Encourage people to improve their dietary intake even if this does not result in them losing weight, because there can be other health benefits (for example, improved lipid profile and reduced risk of type 2 diabetes and cardiovascular disease). [2025]
Ensure that dietary approaches for adults to support overweight and obesity management keep the person's total energy intake below their energy expenditure (also called an energy deficit or calorie deficit). This could be done by lowering specific macronutrient content (for example, low-fat or low-carbohydrate diets) or using other methods to limit overall energy intake. [2025]
Ensure that dietary approaches for children and young people keep their total energy intake at or below the recommended daily calorie intake for their age and sex, depending on their level of overweight or obesity and any weight-related comorbidities. Focus on healthy eating rather than on overly restrictive diets. See the Scientific Advisory Committee on Nutrition guidance on feeding young children aged 1 to 5 years. [2025]
Ensure that any dietary approaches that maintain an energy deficit are offered with support (for example by an appropriately trained healthcare professional such as a Registered dietitian or UKVRN registered nutritionist administered by the Association for Nutrition) and follow up to help people maintain any weight loss in the long term. [2025]
Encourage people to eat a nutritionally balanced diet in the long term, consistent with other healthy eating advice. See the NHS Eatwell guide. [2025]
Advise people not to use restrictive diets that are nutritionally unbalanced, because they are ineffective in the long term and can be harmful. [2025]
For a short explanation of why the committee made the 2025 recommendations and how they might affect practice, see the rationale and impact section on dietary approaches for all ages .
Full details of the evidence and the committee's discussion are in evidence review F: effectiveness of different diets in achieving and maintaining weight loss.
See the NICE recommendation for research about intermittent fasting in adults.
Consider low-energy diets (800 to 1,200 kilocalories per day, also known as low-calorie diets) only as part of a multicomponent overweight and obesity management strategy with long-term support within a specialist overweight and obesity management service (or other services for the management of long-term conditions such as type 2 diabetes) for people:
living with obesity (with or without diabetes) or
living with overweight and with type 2 diabetes.
See the recommendations on classifying overweight, obesity and central adiposity in adults. [2025]
Consider very-low-energy diets (under 800 kilocalories per day, also known as very-low-calorie diets) only as part of a multicomponent strategy within a specialist overweight and obesity management service, for people who:
are living with obesity and
have a clinically assessed need to lose weight rapidly (for example, to make surgery safer and more feasible). [2025]
Do not use low-energy diets or very-low-energy diets as a long-term strategy to manage obesity. [2025]
Ensure that low-energy and very-low-energy diets:
are nutritionally complete
last no more than 12 weeks
include ongoing clinical support and supervision, with access to support from an appropriately trained Registered dietitian or UKVRN registered nutritionist administered by the Association for Nutrition, and advice on reintroducing a wider range of foods (for example, moving on to a nutritionally balanced diet for long-term and sustainable weight loss maintenance). [2025]
Before starting someone on a low-energy or very-low-energy diet as part of a multicomponent overweight and obesity management strategy:
Explain that this is a restrictive diet with a specific health goal (such as improvement in diabetes) and risks (such as weight cycling, weight regain and potential adverse events, and for very-low-energy diets also the risk of constipation, fatigue and hair loss).
Explain that this is not a long-term overweight and obesity management strategy in its own right as it must be followed by lifelong dietary energy intake control and appropriate physical activity levels.
Discuss:
that weight regain is likely to happen, and if it does it is not because they or their healthcare professional have 'failed'
reintroducing a wider range of foods after a low-energy or very-low-energy diet
the options for long-term weight loss maintenance support or therapies (including nutritional advice, physical activity, medicines or surgery) if weight regain happens.
Offer assessment and counselling if they may have eating disorders or other mental health issues, to ensure the diet is appropriate for them.
Review any medicines they are taking and discuss any changes that may need to be made. [2025]
For a short explanation of why the committee made the 2025 recommendations and how they might affect practice, see the rationale and impact section on low-energy and very-low-energy diets for adults .
Full details of the evidence and the committee's discussion are in evidence review F: effectiveness of different diets in achieving and maintaining weight loss.
Avoid a dietary approach alone. Ensure dietary recommendations are part of a multicomponent intervention and are age appropriate and consistent with healthy eating advice. [2006]