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Meal replacement plans: how effective are they?

Obesity and overweight are now a major cause of preventable health problems in the UK. Kate Twine and Lyndel Costain discuss why we should all be taking weight management seriously and consider the evidence for meal replacement plans as a treatment option for weight loss and maintenance

Kate Twine
Dietitian and Nutrition Consultant

Lyndel Costain
Dietitian and Health Writer

The prevalence of obesity has tripled over recent decades. Currently approximately two-thirds of men and women in England are classed as either overweight or obese using standard classifications (see Table 1).(1) By 2010, it is predicted that levels of obesity alone will rise to 28% of women and 33% of men. Therefore it is almost inevitable that any nurse working in primary care will be involved with supporting people who are overweight or obese.


Is it worthwhile treating obesity?
Yes definitely. There are two very good reasons why:

  • Obesity is a major cause of mortality, morbidity and economic and social costs.1 It is associated with numerous serious, chronic diseases including type 2 diabetes, hypertension, coronary heart disease, certain cancers, infertility, osteoarthritis, respiratory disorders and depression.(2,3) It is estimated that 30,000 excess, often premature, deaths in England alone are due to obesity.
  • Modest and realistic weight loss of 5-10% of body weight can significantly improve health status, eg, by improving lipid profile, hypertension and glycaemic control, and reducing insulin resistance and inflammatory markers.(2,4) Diabetes prevention studies have associated it with a 58% reduction in the incidence of progression from impaired glucose tolerance to type 2 diabetes.

Government agendas and healthcare
Despite the rise in obesity and its often serious and wide-ranging effects, it hasn't always been given the focus it deserves. Fortunately, this is changing. The government has placed the prevention and management of obesity and overweight firmly on its agenda. They are addressed in a number of public health and clinical policy and guidance documents, including the NICE Obesity Clinical Guideline, Choosing Health: Making Healthier Choices Easier, the National Quality and Outcomes Framework (QOF) and the obesity PSA (Public Service Agreement) target.(2)
Nurses working in primary care have a pivotal role to play in helping patients to manage their weight. Key requirements include being equipped to identify patients who will benefit from weight loss, to sensitively raise the issue, to offer assessment and, if the patient is in agreement, to help them identify and engage in approaches best suited to their individual needs.(2) National guidance, such as the NICE obesity clinical guidelines, will help to facilitate the implementation of evidence-based care, including identifying health professional training needs.
The weight management options available for adults include improved diet and increased physical activity (incorporating behaviour change strategies, ie, lifestyle changes), drug treatment and surgery. NICE offers clear guidance on different dietary options, such as when to consider linking with commercial and community-based programmes, and when to progress onto more intensive treatments.(2) However, since the UK population continues to live in an environment that promotes sedentary behaviour, with a plentiful and convenient supply of food, sustainable lifestyle changes are the cornerstone off all weight management strategies.

Dietary approaches: what options are available?
In addition to being nutritionally adequate, a key requirement of any dietary approach for weight loss is that it enables energy intake to be less than energy expenditure.(2) There is also increasing recognition that no single dietary approach suits all overweight and obese individuals. Instead treatments are best matched to suit personal preference, lifestyle factors and previous weight control experiences. Recognised dietary treatments include: diets with a 600 kcal/day deficit (600 kcal fewer calories than a person needs to maintain their weight); low-fat diets (that also reduce calorie intake); low-calorie diets (1,000-1,600 kcal/day); meal replacement plans; and very low-energy diets (less than 800 kcal/day). In some cases, these may also be used as part of commercial weight management programmes.

Can commercial approaches be considered for our patients?
The recently published BBC diet trials study, which assessed four commercial weight loss programmes in the UK, concluded: "Given the limited resources for weight management in the NHS, health practitioners should discuss with their patients programmes known to be effective."(5)
In recognition of limited NHS resources and the role of the wider community in healthy weight management, NICE advises that commercial, community or self-help programmes should be considered for patients, as long as they meet best-practice standards (see Box 1). Referring health professionals should also continue to monitor their patients and provide support and care.(2) Meal replacements are one commercial approach that meet the NICE best-practice standards.


Meal replacements
Meal replacements include specially formulated milk shakes, fruit smoothies, soups and meal bars. Purchased from supermarkets and pharmacies, they are designed to take the place of one or two meals a day for weight loss or weight maintenance. They are fortified with nutrients to help ensure consumers receive a full complement of recommended nutrients while losing weight, in line with an EU directive.(6)
It is recommended that meal replacements are consumed as part of a structured eating plan providing 1,200-1,600 kcal/day, depending on the individual's needs. This normally involves:

  • Two meal replacements.
  • One healthy, self-prepared meal of approximately 600 calories.
  • Calorie-controlled between-meal snacks.
  • 1.5-2 litre of low-calorie fluids.
  • Physical activity, preferably daily.

There are numerous published studies assessing meal replacements, including studies in primary care and community settings and a meta-analysis of six randomised controlled trials (see Box 2).(5,8,9) Their results provide evidence that meal replacements can be both safe and effective as part of a weight management plan in obese and overweight people, including those with type 2 diabetes.


One study of particular interest randomised 100 overweight patients to either a 1,200-1,500 kcal meal replacement diet or a 1,200-1,500 kcal conventional "control" diet.(10) Patients on the meal replacement diet lost on average 6 kg more over 12 weeks with improvements in systolic blood pressure, triglycerides, glucose and insulin concentrations. Both groups then moved to a weight maintenance phase, with all patients advised to include one meal replacement per day alongside two healthy meals and snacks. When followed up with monthly meetings with a dietitian, for a further four years, weight loss maintenance and risk factor improvement were achieved, illustrating that meal replacement plans can be an effective option in both the short and longer term (see Figure 1).


Who might meal replacements suit best?
The findings of researchers and professional organisations involved in the management of obesity (see Resources) allow predictions to be made about who may be best suited to meal replacement plans. For example, individuals who:

  • Want a simple and convenient approach to meal planning and preparation.
  • Experience difficulty with self-selection and portion control and therefore like the reassurance of the calorie and portion control provided by meal replacements.
  • Have some form of ongoing support.

Obesity and overweight are now a major cause of preventable health problems in the UK. Guidance is available to facilitate the key role nurses working in primary care have to play in helping patients to achieve modest weight loss and weight maintenance. Sustainable changes to diet and physical activity are the cornerstone of weight management, but this can be challenging in the obesogenic environment we live in. In addition, different approaches to weight management suit different people. The evidence indicates that structured meal replacement plans can be an effective approach, and have gained recognition from key professional organisations as one of a range of possible dietary options for weight management.


  1. NHS. Information Centre. Health survey for England - updating of trend tables to include 2005 data. London: NHS; 2006. Available from:
  2. National Institute for Health and Clinical Excellence. Obesity: the prevention, identification, assessment and management of overweight and obesity in adults and children. London: NICE; 2006. Available from:
  3. Field AE, et al. Impact of overweight on the risk of developing common chronic diseases during a 10-year period. Arch Intern Med 2001;161:1581-6.
  4. Després JP, Lemieux I, Prud'homme D. Treatment of obesity: need to focus on high risk abdominally obese patients. BMJ 2001;322:716-20.
  5. Truby H, et al. Randomised controlled trial of four commercial weight loss programmes in the UK: initial findings from the BBC "diet trials". BMJ 2006;332:1309-14.
  6. Office of Public Sector Information. The foods intended for use in energy restricted diets for weight reduction regulations. London: OPSI;1997. Available from:
  7. Heymsfield SB, et al. Weight management using |a meal replacement strategy: meta and pooling analysis from six studies. Int J Obes Relat Metab Disord 2003;27:537-49.
  8. Ashley JM, St Jeor ST, Schrage JP, et al. Weight control in the physicians office. Arch Intern Med 2001;161:1599-604.
  9. Rothacker DQ. Five year self-management of weight using meal replacements: comparison with matched controls in rural Wisconsin. Nutrition 2000;16:344-8.
  10. Flechtner-Mors M, et al. Metabolic and weight loss effects of a long-term dietary intervention in obese patients: Four-year results. Obes Res 2000;8: 399-402.

British Dietetic Association. Weight Wise campaign, 2006

American Dietetic Association
Evidence analysis library, 2006
W: www.adaevidence

Dietitians in Obesity Management UK
Position statement on meal replacement approaches, 2005 
W: http://domuk.web

National Obesity Forum Adult Weight Management Guidelines, 2006

Diabetes UK
Weight Management: Managing Diabetes in Primary Care