Study (first author, year, reference)	Study characteristics	Participant´s characteristics	Intervention characteristics
Primary care services
Astbury 2018 18 Doctor Referral of Overweight People to Low Energy total diet replacement Treatment (DROPLET) Study	Location: Primary care practices in Oxfordshire, England Design: Pragmatic, two arm, parallel group, open label, individually randomised controlled study Period of the study: 2016–2017 Recruitment: Participants sourced from 10 practices Number of participants allocated: 278 (intervention: 138, control: 140)	Inclusion criteria: BMI ≥30 kg m−2and age ≥18 years Exclusion criteria: People who had received or were scheduled for bariatric surgery, in a weight management programme, or with contraindications to the dietary intervention Baseline age, mean (SD): 37.2 (5.4) Comorbidities at baseline: 23% had hypertension and 15% had diabetes	Delivered by: Intervention: untrained ‘counsellors’ and clinicians. Control: nurses Description: Intervention group: 8 initial weeks with a LED (810 kcal day−1), followed by 4 weeks of food reintroduction. Regular behavioural support was offered. Usual care: Series of appointments for behavioural weight management advice for 12 weeks Duration of active intervention: 24 weeks Length of follow‐up (months): 12
Jackson 2007 23	Location: A moderately deprived health centre from West Yorkshire, England Design: Prospective study Period of the study: 2003–2004 Recruitment: Participants were referred to the clinic by the family physicians, practice‐based nurses and health visitors Number of participants allocated: 89	Inclusion criteria: BMI >35 kg m−2 or BMI >30 kg m−2 with associated comorbidities Exclusion criteria: NR Baseline age, mean (SD): 55.8 (13.8) Comorbidities at baseline: 13.5% had impaired fasting glycaemia	Delivered by: Public health nurse Description: The goal of the clinic was to deliver a specialist health visitor‐led, nonpharmacological intervention to adopt a healthier lifexmlstyle through healthy eating and increasing physical activity Duration of active intervention: Appointments within 3 weeks of the initial referral, then at two weekly intervals for 12 months. Contact after 12 months was negotiated, depending on need Length of follow‐up (months): 12
Read 2004 32	Location: Three health centres in the north locality of Nottingham City Primary Care Trust, England Design: Prospective study Period of the study: 2000–2002 Recruitment: GPs and practice nurses could refer patients opportunistically or patients could refer themselves Number of participants allocated: 216	Inclusion criteria: 18–65 years old, BMI >30 kg m−2 with associated comorbidities Exclusion criteria: current use of obesity medication, insulin treatment of diabetes, pregnancy, and attendance at a hospital obesity clinic Baseline age, mean (SD): 50.4 (12.4) Comorbidities at baseline: 57% had hypertension, 25% had diabetes, 10% had angina, 9% had previous myocardial infarction	Delivered by: Dietitian and nurse Description: Individual assessment appointment before commencing the group sessions. Seven 2‐hour education and support group sessions to improve lifestyles run by the dietitian at intervals of 2 weeks. Further 2‐hour sessions were delivered at 4, 6, 9, and 12 months, Duration of active intervention: 12 months Length of follow‐up (months): 12
McRobbie 2016 29 The Weight Action Programme (WAP)	Location: Six GP surgeries from areas with high levels of social deprivation across London, England Design: Randomised controlled trial Period of the study: 2012–2015 Recruitment: Primarily recruited from the practices, and further advertising was made Number of participants allocated: 330 (intervention: 214, control: 116)	Inclusion criteria: Age ≥18 years and BMI of ≥30 kg m−2 or ≥ 28 kg m−2 with associated comorbidities Exclusion criteria: BMI of >45 kg m−2, had lost > 5% of weight in the previous 6 months, were pregnant, were taking psychiatric medications Baseline age, mean (SD): Intervention 46.6 (15.0) Control 45.1 (14.2) Comorbidities at baseline: Intervention 10% had heart disease, 10% had diabetes Control 6% had heart disease, 8% had diabetes	Delivered by: Intervention health psychologists. Control GPs and practice nurses Description: Intervention group‐based weight loss programme (10–20 participants) delivered over eight weekly group sessions followed by 10 monthly maintenance sessions that combine standard cognitive behavioural interventions, dietary advice and self‐monitoring with group‐oriented interventions. Control Best practice intervention incorporating national guidelines and NHS materials in four one‐to‐one sessions delivered over 8 weeks. Orlistat was an option to participants in both groups Duration of active intervention: Intervention 12 months Control 8 weeks Length of follow‐up (months): 12
Rapoport 2000 31	Location: GP surgeries or local health clinics (geographical location not specified), England (by authors affiliation) Design: Randomised controlled trial Period of the study: Prior to 2000 Recruitment: through letters to GP, posters in health centres and notices in the local media Number of participants allocated: 75 (intervention [modified cognitive‐behavioural therapy]: 37, control [standard cognitive‐behavioural therapy]: 38)	Inclusion criteria: Women aged 18–65 years and BMI of ≥28 kg m−2 Exclusion criteria: being involved in any other method of weight management, serious medical or psychiatric conditions (including eating disorders), insulin dependent diabetes, and pregnancy or lactation Baseline age, mean (SD): Intervention 49 (10) Control 46 (12) Comorbidities at baseline: None reported	Delivered by: Registered dietitian and a health psychologist, a clinical psychologist and an exercise scientist Description: Both treatment programmes involved weekly, 2h sessions over a 10‐week period, with around 10 participants in each group. Intervention: The programme emphasised regular physical activity and healthy eating as means to improve overall health rather than focusing in weight loss using used basic behavioural and cognitive principles incorporating incorporated elements from psychoeducational, nondieting and feminist approaches. Control: Moderate energy deficit giving approximately 1200 kcal day−1. Participants were asked to set specific weight loss goals, basic behavioural and cognitive principles Duration of active intervention: 10 weeks Length of follow‐up (months): 12
Little 2017 26 POWeR+ (Positive Online Weight Reduction) Programme	Location: General practices around the centres of Southampton and Oxford, England Design: Randomised parallel‐group study Period of the study: 2013–2014 Recruitment: General practices identified participants from their electronic records, and up to 100 patients from each practice were randomly chosen and invited by letter Number of participants allocated: 826 (intervention [face‐to‐face]: 269, intervention [remote]:270 control: 279)	Inclusion criteria: BMI of ≥30 kg m−2 or ≥ 28 kg m−2 with associated comorbidities Exclusion criteria: Major mental problems, very severe illness (difficulty completing outcomes and were unable to change diet), were pregnant or breastfeeding, or had a perceived inability to walk 100 m Baseline age, mean (SD): intervention [face‐to‐face]: 53.7 (13.2), intervention [remote]: 54.7 (13) control: 52.7 (13.3) Comorbidities at baseline: 17% in the intervention [face‐to‐face], 16% in the intervention [remote] and 17% in the control group had diabetes	Delivered by: Nurses Description: Control: advice and simple materials to support behaviour change. Intervention [face‐to‐face]: Web intervention to teach patients self‐regulation and cognitive behavioural techniques to form sustainable eating and physical activity, 24 web‐based sessions designed to be used over 6 months. Participants had three scheduled face‐to‐face appointments in the first 3 months and then up to four more during the next 3 months. Intervention [remote]: Patients could access the same web‐based intervention as in the face‐to‐face group and the intervention was to assess whether even briefer professional support for the web intervention could be effective. In addition to 6 monthly weighing, as in the control group, participants had three scheduled telephone or e‐mail contacts and up to two optional telephone/e‐mail contacts during the first 6 months) Duration of active intervention: 6 months Length of follow‐up (months): 12
Ross 2008 21 Counterweight Programme Project (UK)	Location: 65 general practices from seven UK regions Design: Prospective study Period of the study: 2000–2005 Recruitment: Patients were identified by GPs and practice nurses during normal appointments Number of participants allocated: 1906	Inclusion criteria: Age 18–75 years and a BMI of ≥30 kg m−2 or ≥ 28 kg m−2 with associated comorbidities Exclusion criteria: Not reported Baseline age, mean (SD): 49.4 (13.5) Comorbidities at baseline: 13.5% had diabetes, 32.1% had hypertension, 12.5% had dyslipidaemia, 8% had cardiovascular disease and 9.9% had impaired glucose	Delivered by: Practice staff (GPs, nurses and healthcare assistants) trained by registered dietitians with expertise in obesity management Description: The practice nurse/healthcare assistant role was to deliver patient education through discussion about weight management, communication of information, and the transfer of behaviour change skills and strategies during weight management sessions. The aim was to achieve an energy deficit of 500–600 kcal day−1. Participants were asked to commit to nine appointments in 12 months (included six initial appointments of 10–30 minutes each, with follow‐up visits at 6, 9 and 12 months) Duration of active intervention: 12 months Length of follow‐up (months): 24
Ross 2012 22 Counterweight Programme Project (Scotland)	Location: 13 Health Boards (including 184 general practices, 16 pharmacies), Scotland. Mainly delivered in general practices, but one Health Board chose a pharmacy setting and another favoured community‐based implementation of the programme Design: Prospective study Period of the study: 2006–2008 Recruitment: Counterweight Programme was positioned alongside ‘Keep Well’ for practice recruitment and screening of patients Number of participants allocated: 6715	Inclusion criteria: 40–64 years (specification for the ‘Keep Well’ programme), BMI of ≥30 kg m−2 or ≥ 28 kg m−2 with associated comorbidities Exclusion criteria: Not reported Baseline age, mean (SD): 53.0 (10.4) Comorbidities at baseline: From those enrolled by 16 community pharmacies (n = 458), 11.6 % had diabetes	Delivered by: Practice staff (GPs, Nurses and healthcare assistants) trained by registered dietitians with expertise in obesity management Description: As described previously (see Ross et al. 21). Duration of active intervention: 12 months Length of follow‐up (months): 12
Lean 2013 25 Feasibility study for Counterweight Plus programme	Location: Practices already delivering Counterweight, predominately in rural or small‐town settings in Scotland Design: Prospective study Period of the study: Prior to February 2013 Recruitment: Participants were proposed by GPs, practice nurses, or local dietitians Number of participants allocated: 91	Inclusion criteria: 20–60 years with BMI ≥40 kg m−2 Exclusion criteria: pregnancy or lactation, diabetes and taking insulin, myocardial infarction cancers, chronic pancreatitis, alcohol dependence, psychiatric illness, and learning disability Baseline age, mean (SD): 45.7 (10.7) Comorbidities at baseline: Not reported	Delivered by: Practice nurses, physicians and dietitians Description: The intervention was delivered in practices that were delivering the Counterweight programme (see Ross et al. 22). There was an initial phase of 12 weeks of LED (810–833 kcal day−1) with weekly appointments for the first 12 weeks. Then a food reintroduction phase of 6–8 weeks with one 360–400 kcal meal day–1 followed by a weight maintenance phase of 34 weeks. All nutrition from food was based on individualised food portion plan based on 500–600 calorie deficit day–1 with an upper limit of 2500 kcal day−1 in the last phase. 30 min per day of moderate physical activity was encouraged. Telephone support was provided if necessary. Orlistat was optional for participants Duration of active intervention: 12 months Length of follow‐up (months): 12
McCombie 2019 28 Counterweight‐Plus Programme Project (UK)	Location: A variety of UK providers Design: Prospective study Period of the study: 2013–2018 Recruitment: Participants recruited from nine UK Health Service areas, one private weight management service, eight private freelance Counterweight‐Plus trained practitioners Number of participants allocated: 288	Inclusion criteria: Age 18–75 years and a BMI of ≥30 kg m−2 or ≥ 28 kg m−2 with associated comorbidities Exclusion criteria: Active mental illness, myocardial infarction or stroke within the previous 3 months, severe or unstable heart failure, porphyria, pregnant and until >4 months post‐partum, breastfeeding, substance abuse or eating disorder accompanied by purging Baseline age, mean (SD): 45.7 (12.7) Comorbidities at baseline: 34.4 % had diabetes (97% type 2 diabetes and 3% type 1 diabetes)	Delivered by: registered healthcare professionals (mainly registered dietitians) with specialist training in weight management, with access to consultant physician expertise Description: Seven 60 min appointments over 12 weeks (or up to 20 weeks if greater weight loss required), where LED (825–853 kcal day−1) products and written resources are provided. Then a food reintroduction phase with six appointments of 20 min over 6–12 weeks. Increased physical activity, 30 min of moderate activity day–1 at least 5 days/week. Once achieved, aim for 45–60 min of moderate activity day–1 (monitoring with step‐counters or activity trackers if possible). Orlistat available depending on local prescribing access. Seven appointments given to consolidate behavioural change strategies and restrict weight regain Duration of active intervention: 12 months Length of follow‐up (months): 12
NHS Specialist Weight Management Clinics (Secondary Care)
Barrett 1999 19	Location: The Luton and Dunstable Hospital specialist multidisciplinary obesity services, England Design: Retrospective study Period of the study: Prior to 1999 Recruitment: Patients referred by General Practitioners Number of participants allocated: 115	Inclusion criteria: Referral to the clinic was often prompted by physical health problems related to obesity Exclusion criteria: Lack of motivation or an eating disorder Baseline age, mean (SD): 42 (NR) Comorbidities at baseline: 34% had hypertension; 11% had non‐insulin dependent diabetes and 41% had dyslipidaemia	Delivered by: Consultant physician, clinical psychologist and a senior dietitian Description: Seven closed group sessions providing formalised behaviour and cognitive modification combined with an initial VLED (600–800 kcal day−1). Pharmacology treatment was given upon evaluation. After completing 12‐week programme, patients returned to clinic at 3‐month intervals for advice and weighing. Duration of active intervention: 12 weeks Length of follow‐up (months): 18
Cartwright 2014 20	Location: Specialist Weight Management Heart of England NHS Foundation Trust and the former South Birmingham Primary Care Trust (but the programme was delivered at local general practices), England Design: Prospective study Period of the study: 2008–2012 Recruitment: Patients referred from primary care settings in West Midlands Number of participants allocated: 262	Inclusion criteria: Age 19–76 years with BMI of ≥40 kg m−2 or ≥ 35 kg m−2 with associated comorbidities Exclusion criteria: Not reported Baseline age, mean (SD): 43.1 (11.8) Comorbidities at baseline: 26.3% had diabetes, 11.1% had cardiovascular disease, 34.4% had hypertension, 24% had arthritis, and 25.6% had obstructive sleep apnoea	Delivered by: Physicians, dieticians and a psychologist Description: Comprehensive multidisciplinary care delivered through individual appointments at GP practices. The frequency of contact was every three months, but varied with individual requirements and session availability, with individuals attending subsequent appointments every two to three months or more frequently if needed. Totalling a range of contacts from 5 to 13 Duration of active intervention: 12 months Length of follow‐up (months): 36
Rolland 2009 33	Location: Specialist Obesity Clinic, Scotland Design: Randomised controlled trial Period of the study: Prior to 2009 Recruitment: Patients were referred by primary care services Number of participants allocated: 120 (After three months: VLED group 34, Low carbohydrate group 38, Energy deficient group 18)	Inclusion criteria: Age over 18 years with BMI of ≥35 kg m−2 Exclusion criteria: history of hepatic or renal disease, cancer, currently pregnant or lactating, on antidepressants or anti‐obesity medication, eating disorders Baseline age, mean (SD): Not available for the whole sample. VLED 39.9 (10.4), Low‐carbohydrate group 42.7 (13.1) Comorbidities at baseline: Not reported	Delivered by: Physician and dietitian Description: Patients initially underwent a dietary treatment with a low fat, 600 kcal day−1 deficit diet for three months. If patients responded well, it was continued for 9 months. If patients fail to lose weight with it, they were randomised to LighterLife VLED (550 kcal day−1) plus group support weekly or a low carbohydrate/high protein (800–1500 kcal day−1) diet for 9 months Duration of active intervention: 12 months Length of follow‐up (months): 12
Packianathan 2005 30	Location: England, no other details Design: Longitudinal study Period of the study: Priori to July 2005 Recruitment: Through advertisements in local news media Number of participants allocated: 150	Inclusion criteria: Women, aged 35–65 years, with a BMI 35–45 Exclusion criteria: If women were dieting, had a secondary cause of obesity, were on drugs known to affect energy balance, had a history of eating disorder, had lactose intolerance or had significant comorbidity Baseline age, mean (SD):48.5 (8.3) Comorbidities at baseline: Excluded if participants had a comorbidity	Delivered by: Dietitian and physicians Description: Phase 1 included a 16‐week acute weight loss intervention with 900 kcal day−1 with SlimFast plus biweekly for a one hour dietetic and cognitive behavioural therapy. Second phase up to 10 SlimFast meal replacements/week, optional 900 kcal day−1 for relapse, or patients could choose a low‐fat diet with a 600 kcal day−1 energy deficit, plus group dietetic and lifestyle therapy, behavioural modification and advice on increased physical activity Duration of active intervention: 12 months Length of follow‐up (months): 12
Jennings 2014 24	Location: NHS Fakenham weight management service, England Design: Cohort study Period of the study: 2011–2012 Recruitment: Referrals were accepted from General Practitioners Number of participants allocated: 230	Inclusion criteria: Age >18 years with a BMI of ≥40 kg m−2 or ≥ 35 kg m−2 with associated comorbidities and/or waist circumference ≥102 cm in men or ≥88 cm in women Exclusion criteria: pregnancy, severe eating disorder, poor motivation identified by a motivational questionnaire, or failure to respond to an invitation to contact the service Baseline age, mean (SD): 52.7 (13.6) Comorbidities at baseline: 31.7% had diabetes, 0.43% had impaired fasting glycaemia, 11.7% had ischaemic heart disease, 38.3% had hypertension, 11.7% had sleep apnoea and 31.3% had depression	Delivered by: General practitioner with additional training as a bariatric physician, specialist nurses, dietitian, psychological therapist, exercise professional, health trainer and supported by a consultant endocrinologist and public health consultant Description: The service aimed to deliver interventions including medical assessment, motivational interviewing to support behaviour change, dietary and activity advice, psychological therapies, drug therapy with orlistat, medically supervised LEDs and assessment for suitability for bariatric surgery. The exercise professional provided both individual and small group sessions at the on‐site gym, and there was a 12‐week exercise referral scheme using local gyms. The number of visits ranged from 10–15 visits for the 1‐year programme Duration of active intervention: 12 months Length of follow‐up (months): 12
Ryan 2017 35	Location: NHS Specialist weight management service in the North East of England Design: Retrospective study Period of the study: 2013–2014 Recruitment: Participants were referred by General practitioners Number of participants allocated: 167	Inclusion criteria: BMI of ≥40 kg m−2 or ≥ 35 kg m−2 with associated comorbidities, registered with a local GP; aged >16 years; with an ability to take charge of their dietary intake; assessed as ‘ready to change’; and have had previous attempts at weight loss Exclusion criteria: suspected or diagnosed malignancy, pregnant, or requiring post‐bariatric care (unless previously known to the service) Baseline age, mean (SD): 52.2 (11.9) Comorbidities at baseline: Not reported	Delivered by: Dietician, physiotherapist, psychologist, metabolic physician/endocrinologist, GP with a specialist interest in obesity management Description: In phase 1, patents initially received an individual care plan that included an exercise and physical activity plan; outcomes expected; target weight; behavioural goals; and other tools and educational materials. In phase 2, patients move into group services and treatment according to their specific needs and care plan. In phase 3, patients were discharged from the service with details of the patient's outcomes and an ongoing care plan sent to their GP Duration of active intervention: 12 months Length of follow‐up (months): 12
Steele 2017 36 Aintree LOSS	Location: Hospital clinic, General Practice (GP) surgeries, community centres and a sports centre in Liverpool, England Design: Retrospective study Period of the study: 2009–2013 Recruitment: Based primarily in the community, and referrals are predominantly received from primary care teams, although referrals are also accepted from elsewhere, including secondary care and community dietetics Number of participants allocated: 2457	Inclusion criteria: BMI of ≥40 kg m−2 or ≥ 35 kg m−2 with associated comorbidities Exclusion criteria: Not reported Baseline age, mean (SD): 48.6 (13.8) Comorbidities at baseline: 26% had diabetes, 21.7% had sleep apnoea, 47.7% had depression, 39.8% had hypertension, 32.4% had hyperlipidaemia, 5.2% had myocardial infarction, 6.8% had ischaemic heat disease, 3.3% had stroke and 47.3 had join pain	Delivered by: General practitioners, physician with a special interest in obesity, dieticians and physiotherapists psychologists and occupational therapists Description: A personalised management plan agreed from a list of dietetics, physiotherapy, occupational therapy and cognitive analytical and behavioural therapy, as well as group sessions (joint physiotherapy, dietetics and hydrotherapy). Group sessions run for 2 h per week for 12 weeks. Individual reviews took place every 1 to 3 months depending on the intensity of intervention required. Contact with leisure services via swimming session was offered. Orlistat was offered as an option to participants Duration of active intervention: 24 months Length of follow‐up (months): 24
Logue 2014 27	Location: NHS, Glasgow and Clyde Weight Management Service, Scotland Design: Prospective observational study Period of the study: 2008–2011 Recruitment: Referred by their GP or hospital doctor Number of participants allocated: 1838	Inclusion criteria: Aged ≥18 years with a BMI of ≥35 kg m−2 or ≥30 kg m−2 with associated comorbidities Exclusion criteria: Not reported Baseline age, mean (SD): 49.1 (13.5) Comorbidities at baseline: Not reported	Delivered by: Service lead, team leaders, dieticians, clinical psychologists, psychology assistant, physiotherapists, administrative staff and technical support staff Description: Educational lifestyle programme that included cognitive behavioural therapy and 600 kcal day−1 deficit diet and physical activity advice. Phase 1 comprised nine fortnightly 90 min sessions over a 16 weeks. Then patients could choose to enter phase 2 (three 1 h sessions delivered at monthly intervals plus a range of treatment options including further lifestyle advice, prescribed low calorie diet or orlistat). At the end of phase 2, or directly from the end of phase 1, patients could enter a weight maintenance programme (3rd phase) comprising twelve monthly 1 h sessions. Patients who fail to achieve their target weight loss could choose to repeat phase 2 once more and then enter the maintenance programme or opt for bariatric surgery Duration of active intervention: 12 months Length of follow‐up (months): 12
Wallace 2015 37 The ‘Live Life Better’ Service	Location: NHS weight management service from Derbyshire County, England Design: Cohort study Period of the study: 2010–2013 Recruitment: Referred by their GP or hospital doctor Number of participants allocated: 551	Inclusion criteria: BMI of ≥40 kg m−2 or ≥ 35 kg m−2 with associated comorbidities Exclusion criteria: Not reported Baseline age, mean (SD): 45.7 (13.3) Comorbidities at baseline: 33.2% had hypertension, 3.8% had ischaemic heart disease, 22.1% had diabetes, 1.1% had stroke, 16.3% had asthma, 24.9% chronic join problems, 11.8% osteoarthritis	Delivered by: Psychologist, dietitian or physiotherapist Description: An intensive lifestyle modification‐based programme involving psychological support, behaviour change strategies, physical activity, dietetic advice and occupational therapy where relevant. (No further details are provided) Duration of active intervention: 24 months Length of follow‐up (months): 24
Commercial programmes
Rolland 2014 34 LighterLife Total	Location: Scotland Design: Retrospective study Period of the study: 2007–2010 Recruitment: Self‐referred Number of participants allocated: 5965	Inclusion criteria: ≥ 30 kg m−2 Exclusion criteria: Type 1 diabetes, porphyria, lactose intolerance, major cardiovascular or cerebrovascular disease, history of renal disorder or hepatic disease, cancer; epilepsy, major depressive major psychiatric or eating disorders, pregnant or breastfeeding, have given birth or had a miscarriage in the last 3 months Baseline age, mean (SD): 45.6 (10.2) Comorbidities at baseline: Not reported	Delivered by: ‘Trained weight management counsellors’ Description: LighterLife Total VLED programme (550 kcal day−1) and group support (in small, single‐sex, weekly groups for the facilitation of behaviour change for the treatment of obesity), along with behavioural therapy. Duration of active intervention: Not reported Length of follow‐up (months): 12

GP, general practitoner; LED, low‐energy formula diet (800–1200 kcal day⁻¹); VLED, very‐low‐energy formula diet (<800 kcal day⁻¹).