Stop using body mass index as measure of health, say MPs
BMJ 2021; 373 doi: https://doi.org/10.1136/bmj.n941 (Published 09 April 2021) Cite this as: BMJ 2021;373:n941
The UK government’s approach to eating disorders and poor body image is “potentially harmful” and “triggering” for the people it is meant to help, MPs have said.1
MPs on the House of Commons Women and Equalities Committee have called on the government to urgently order an independent review of its obesity strategy to ensure that it is evidence based.
They also said that body mass index (BMI)—originally introduced to measure entire populations—should no longer be used to determine whether an individual person’s weight is healthy. Calories on menus should also be scrapped, they advised, and the use of altered images in commercial advertising and promotion should be more strictly controlled.
The government’s obesity strategy published in July 2020 included measures such as a ban on television and online advertisements for food high in fat, sugar, and salt before 9 pm; calorie content being displayed on restaurant menus for food and alcoholic drinks; and an end to “buy one, get one free” deals on unhealthy food.
At the time, medical leaders said that the strategy would fail unless the government had the “courage to stand up to industry where it matters” and emphasised that it should focus more on the social factors that lead to obesity.2
The committee has now pointed to research by the University of Cambridge, which found that over the past 30 years government campaigns around obesity had been “largely unsuccessful due to problems with implementation, lack of learning from past successes or failures, and a reliance on trying to persuade individuals to change their behaviour rather than tackling unhealthy environments.”
Use of BMI
The report highlighted that many people had reported facing discrimination based on appearance and weight when accessing NHS services, and it concluded that the use of BMI “inspires weight stigma, contributes to eating disorders, and can damage an individual’s body image and mental health.”
Instead, the committee has recommended that the government’s public health campaigns adopt a “health at every size” approach—defined as treating patients while honouring differences in size, age, race, ethnicity, gender, ability and disability, sexual orientation, religion, class, and other human attributes.
The report argued that BMI was a “very poor proxy of health,” as two people with the same BMI can have very different physical and mental health. Additionally, BMI was historically based on studies of European men, meaning that it may not give an accurate portrayal of health in other groups, including different ethnic groups and women.
The report also called for the government to urgently commission research into the extent of weight based discrimination and its impact on people accessing NHS services.
The committee chair, Caroline Nokes, said, “The use of BMI as a measure of healthy weight has become a kind of proxy or justification for weight shaming. This has to stop.
“We are particularly alarmed by the rise in eating disorders and concerned that the obesity strategy, and data collection of obesity levels in kids, makes things worse by failing to promote healthy behaviours. The government must ensure its policies are not contributing to body image pressures.”
The report warned that the pandemic had had a devastating impact on people with an eating disorder and those at a high risk of developing one, and it highlighted rapidly rising rates of these disorders and other mental health conditions.
The committee has called on the government to review why rates are rising in the UK and to report back within six months with findings and policy interventions.
Among a raft of other recommendations was that funding for research into eating disorders should match the £9 (€10.40; $12.40) per person research funding for people with mental health issues. It currently stands at 96p.