A number of evidence-based weight management interventions are now available with different models and serving different patient/client groups. While positive outcomes are a key to the decision-making process, so too is the information around how these outcomes were achieved, in what population, how transferable the outcomes would be to the population a service would be aiming to cover and at what cost to the service provider and or the individual. This paper examines all the UK interventions with recent peer-reviewed evidence of their effectiveness in ‘realistic’ settings and cost-effectiveness, in the context of National Institute of Health and Clinical Excellence (NICE) and Scottish Intercollegiate Guideline Network (SIGN) guidelines. It concludes that the evidence-based approaches allow intervention at different stages in the disease process of obesity, which are effective in different settings. Self-referral to commercial agencies, by individuals with relatively low body mass index (BMI) and few medical complications, is a reasonable first step. For more severely obese individuals (e.g. BMI > 35 kg m−2) requiring more medically complicated care, evidence is largely lacking for these services, but the community-based Counterweight Programme is effective and cost-effective in maintaining weight loss >5 kg up to 2 years for 30–40% of attenders. For more complicated and resistant obesity, referral to a secondary care-based service can generate short-term weight loss, but 12-month data are unavailable.