There are a wide range of commercial weight loss options available to the general public, which vary in cost. It is not known which products and services offer the most effective and cost-effective results for weight loss and maintenance.
Description of the condition
Overweight and obesity are major preventable health burdens facing most middle and high income countries. Both overweight and obesity are defined as excessive fat accumulation that presents a risk to health (WHO 2013).
Trends indicate that a shift in energy balance, predominately excess energy intake exceeding energy expenditure rather than changes in our gene pool have led to the high levels of obesity and overweight we see in many countries (WHO 2013).
The body mass index (BMI) is the preferred method of body fat measurement in clinical settings, for practicality, and cost effectiveness to illustrate the health risks associated with a raised BMI (Gray 1991). However, BMI as a measurement method is only a proxy measure of body fatness. BMI is a measure of weight relative to height, calculated by dividing weight (kg) by height (m2) (Foresight 2007). The World Health Organization (WHO) has identified particular cut-off points for the classification of underweight, ideal, overweight and obese adults (WHO 2006).
Underweight is defined as BMI < 18.5, normal weight is BMI 18.5 to 24.9, and overweight is BMI 25 to 29.9. Obesity is classified in three categories: class I obesity (BMI 30.0 to 34.9), class II obesity (BMI 35.0 to 39.9), and class III - morbid obesity (≥ 40.0). BMI must be used with caution: This method of measurement assesses total body weight irrespective of muscle and fat mass. Certain populations (elderly and athletes) could fall into incorrect categories in recognition of their BMI classification.
WHO has identified intermediate action points for Asian populations. However, these are not universal across all ethnicities. Studies that have included non-Caucasian populations should use BMI adjusted calculations for the participants involved.
Ideally, additional methods of assessment should be utilised to predict health risks associated with an increased fat mass (waist circumference and waist-to-hip ratio). However, caution should be used. Defined waist circumference protocols (minimal waist, umbilicus, immediately above the iliac crest, and midpoint point between the lowest rib and immediately above the iliac crest) correlate with different health related risk factor cut-off points.
The prevalence of obesity and overweight is not confined to Western populations. Deprived and developing countries have observed malnutrition equalling obesity (Lobstein 2004). Globally it is estimated that by 2015, approximately 700 million adults will be obese, and 2.3 billion will be overweight. If trends do not subside, 50% of the United Kingdom’s population could be defined as obese by 2050 (Foresight 2007). There are indications from some countries that the rate of increase may have plateaued, for example in the US at about a third of the population (Flegal 2010). One in 10 five to seventeen year olds are classified as overweight, a total of 155 million, and 1 in 50 are classified as obese which accounts for 30 to 45 million of the presented figure (Lobstein 2004). The National Child Measurement Programme (NCMP) data set of four to five year olds and 10 to 11 year olds in England, 2009/2010 reported that in 23.1% of the younger children measured were either overweight or obese, one in three (33.4%) of the older children measured were either overweight or obese (Health and Social Care Information Centre 2010).
Obesity accounts for a plethora of physical, social and psychological consequences, and is associated with type 2 diabetes, hypertension, congestive heart failure, certain cancers, and non-alcoholic fatty liver disease. Obesity is also associated with early mortality (National Audit Office 2001).
Financial costs incurred to the individual and the state account for a considerable amount of state expenditure regardless of the country of origin. Indirect effects of obesity can be measured, calculating increased number of sick days, earlier retirement, decreased performance, loss of earnings, and loss of productivity and capability. Direct costs relate to the prevention, diagnosis and treatment of obesity.
At an individual level, increases in the consumption of whole grains, nuts, legumes, fruits, vegetables and physical activity is recommended, paralleled with the limitation of total fats, and reduced intake of sugars.
As a result of the rise in obesity prevalence, the search for cost-effective interventions is of paramount importance. Numerous treatment options are available via primary care providers, and available for purchase at an individual level, including bariatric surgery, pharmacological interventions, behaviour modification, and commercial alternatives.
Lowe 2001 report an increasing amount of overweight individuals who seek treatment in the commercial environment. However, insufficient evidence supports long-term effectiveness of commercial interventions (Ditschuneit 2001; Foster 2003; Heshka 2003). Research traditionally lies within short-term studies, reporting effectiveness of commercial alternatives (Heshka 2000).
Discontinuation of a commercial treatment option results in weight regain in 33% to 66% of individuals within the first year, and the majority of lost weight is regained within five years (Lowe 2001), warranting the requirement of effective long-term evaluation and research.
Some of the most recognisable commercial weight loss products and services have been established for only four decades. The last 10 years have seen the companies who produce and deliver these products and services strengthening their delivery, marketing strategies, and the sharing of results with the rest of the weight loss industry. It is uncertain whether commercial weight loss products and services are a cost effective method for weight loss maintenance (Gosselin 2001).
Within the United Kingdom, some primary care trusts have offered a referral option to commercial weight loss programmes, such as Weight Watchers (http://www.weightwatchers.com/) and Slimming World (http://www.slimmingworld.com/), but often for just a duration of12 weeks. Literature does not specifically illustrate why certain programmes have been favoured over others, other than their popularity in the public domain. As the value of the commercial sector which aims to help people lose weight continues to rise (it currently exceeds £2 billion (€2.3 billion) (Foresight 2007), it is of paramount importance to conduct research in relation to effectiveness of commercial weight loss products and services and translate this information to policy and practice so that they, and the public, can make better informed treatment choices.
Description of the intervention
Commercial weight loss products and services have increased in number, patterned with rising obesity and overweight prevalence (Hamilton 2004). Marketing of these products and services has been observed in various venues and advertising spaces, including online. There is a wealth of choice available to users in terms of types of products and services available for adults, including dietary supplements, own-brand groceries, meal replacement products, menu guides combined with food planning, and food calorie points systems. Numerous popular products and services focus on group support, led by an individual who has succeeded in the programme, and is maintaining their weight.Â Individuals who wish to lose weight through commercial weight loss products and services have a considerable amount of choices. Evidence to justify weight maintenance is overwhelmed by marketing strategies. Specifically for this systematic review, we will concentrate upon interventions that are commercial weight loss products and services which deliver advice via a number of settings and media (e.g. face to face group settings, online) where advice is restricted to diet and/or physical activity behaviour change, including meal replacements. The review will not include products and services which include weight loss drugs, hypnotherapy or hypnosis, incentives, or nutriceuticals.
Adverse effects of the intervention
Research has not specifically examined the adverse effects of commercial weight loss products and services, systematic assessment is required. Specifically, we will include information in relation to attrition and uptake of said interventions.
How the intervention might work
Increasing number of people turn to the commercial market for weight loss treatment (Lowe 2001). Research suggests that weight loss maintenance could be more effective for individuals who start a group-based behavioural treatment programme (Akers 2010). However, individual based programmes have also shown positive results (Rock 2010). Techniques taught by the programmes reviewed could be more successful in relapse prevention and problem solving. The format of the programme could also impact upon weight and BMI changes.
Why it is important to do this review
Advice on weight loss from primary care providers has been shown to be effective (Levy 1988). Individuals who wish to gain guidance and advice from a practitioner in relation to commercial weight loss products and services are often not able to do so, practitioners may feel ill equipped to confidently provide this information (Tsai 2005). In order to assist practitioners, and prior to selecting a commercial weight loss product or service, systematic synthesis of evidence is required. Commercial weight loss products and services are limited in number. However, short-term effectiveness has been demonstrated (Heshka 2000). Primarily, consumers and practitioners require information concerning cost-effectiveness, ascertaining how much a product or service costs for a prescribed and advised intervention period (12 weeks), and whether weight will be regained after the individual has discontinued with the product or service.
Commercial weight loss treatment options require evaluation to assess effectiveness, and to assist commissioners of service. This evidence is equally important for users in order to help them choose a method that is based upon evidence rather than marketing strategies.
Health inequalities could be tackled by marketing of commercial weight loss interventions targeting individuals with lower socio-economic status. Research suggests that socio-economic status is patterned with obesity and overweight prevalence (House of Commons Health Committee 2004). Specific areas of the United Kingdom with low socio-economic status, and increased deprivation could be widening the health inequalities gap via differential purchase of commercial weight loss treatment options.