History | World Obesity Federation


The World Obesity Federation has existed as we are now since 2014, but our roots go much further back than that. From the creation of the Obesity Association in 1967, through the global outreach of the 70s, 80s and 90s, and into the modernisation of 21st Century - we have come a long way.

World Obesity (formerly IASO) History

Obesity has been a growing health problem since infectious diseases and nutrient deficiencies began to fade in the first half of the 20th century. Whilst the earliest identified discussions on the need for an organisation addressing obesity took place in Great Britain as early as 1961, it was not until 1966 that a steering committee was formed. The first meeting of the "Obesity Association" was held in London in 1967, followed the next year by a second London meeting in the form of a Symposium on Obesity.


In the 1970s, the field of obesity research began to blossom in Europe.  In the UK, Philip James and John Waterlow prepared an analysis of obesity-related research needs for the Department of Health and the UK Medical Research Council, enticing medical establishments to start funding obesity research.

Clinicians and physiologists in Western Europe began to examine heat exchange, energy metabolism and genetics, while Scandinavian research focused on physical activity, metabolic consequences, and early childhood influencers of fat cell quantity. This era also witnessed the development of Fenfluramine - a new drug to treat obesity.

Around the same time, the Fogarty International Center at the National Institutes of Health in the USA began planning a number of international conferences focusing on major diseases. The first Fogarty Center International Conference on Obesity was organised by a committee led by Dr. George Bray, and was held in October 1973 at NIH in Bethesda, Maryland.

In preparation for the Fogarty Conference, Dr. Bray and Dr. Howard, one of the organisers of the Association for the Study of Obesity in Great Britain, articulated the need for a continuing series of international congresses on obesity as well as a publication devoted to work in the field. As a result, the 1st International Congress on Obesity (ICO) was held at the Royal College of Physicians in London in October 1974, with over 500 attendees from 30 countries.

Quarterly publication of The International Journal of Obesity (IJO) began in 1977, with Drs. Bray and Howard as its founding co-editors. In the same year the 2nd ICO and the 2nd Fogarty International Conference on Obesity were both held during October in Washington DC. Thus, by the end of the 1970's both an international journal and a three yearly pattern of international congresses had been established.


If the 70s was a decade of foundation laying, the 80s was a time of consolidation and construction, witnessing the birth of the International Association for the Study of Obesity (IASO).

 In 1980, at the meeting of the Nutrition Committee of the American Heart Association, Dr. John Brunzell and Dr. George Bray discussed the lack of an organised American group with an obesity focus. Shortly afterwards, American scientists interested in obesity were invited to the North American Association for the Study of Obesity (NAASO) at Vasser College in 1982. The formative organisational committee meeting of IASO occurred soon after at the International Union on Nutrition Sciences meeting in Brighton, England in 1985. By 1986 when the 5th ICO met in Jerusalem, Israel in 1985, IASO’s structure was put in place, its constitution and by-laws adopted and the first officers elected.

As an international association, IASO General Council membership included: two representatives from each national obesity association, concerned individuals from countries without them, and the ICO past presidents/chairs. General Council responsibilities included enhancing communication between the various associations, site selection for future congresses, oversight and editor selection for the IJO through a Publication Committee, and selection of IASO Awards winners.

The Willendorf Award for outstanding contributions to clinical research in obesity was first made in 1980 to Dr. George Bray at the 3rd ICO in Rome. This was followed by the establishment of the Andre Mayer Award for Young Investigators in 1983, with Paul Trayhurn as the first awardee, and the Wertheimer Award for outstanding contributions to basic investigations in obesity in 1986 awarded first to Benjamin Shapiro, PhD.


The 90s were the decade of maturation, and several important developments increased IASO’s prominence on the international scene.

The 6th, 7th and 8th ICOs were held respectively in Kobe, Japan in 1990; Toronto, Canada in 1994; and Paris, France in 1998, with attendance that reached 3000. During this time, obesity meetings were occurring throughout Europe on an annual basis, and   IASO nurtured the establishment of two new regional associations: the Latin American Federation of Societies of Obesity (FLASO) was established in 1990 in Chile, and in 1999 the Asia-Oceania Association for the Study of Obesity (AOASO) was set up. With these regional organisations, IASO became well-positioned to host future ICOs (2002 in Sao Paulo, Brazil and 2006 in Sydney, Australia) and a series of vibrant Asia-Oceania meetings. The number of publications dedicated to obesity grew during the decade, with the founding of "Obesity Research" by NAASO in 1993, and IASO’s addition of a new review journal entitled "Obesity Reviews" in 1998. Membership in the General Council of IASO increased to 39 countries during the decade.

The other significant development was the formation by Philip James in 1995 of the International Obesity Task Force (IOTF). As a policy and advocacy ‘think tank’, the IOTF was formed to alert the world to the growing health crisis threatened by soaring levels of obesity. Comprised of leaders in the academic obesity community worldwide, the IOTF prepared the first scientific research report on the global epidemic of obesity, which served as the basis for the first WHO expert consultation on obesity held in Geneva in 1997. The IOTF formally constituted at the European Congress of Obesity (ECO) in Barcelona 1996, and became a formal subcommittee of IASO at the 1998 meeting in Paris.

In 1998 IASO began to share a London office with the IOTF, which registered as a charity in 1999 giving it legal status to operate. In the same year IASO appointed its first Executive Director, Kate Baillie, to transition the organisation from voluntary to paid management and to professionalise its operations.  Over the following three years, the work of IASO and the IOTF formed the basis for consultations to various governments and other agencies worldwide, with both organisations well represented in the WHO expert group which revised the original Diet, Nutrition and Prevention of Chronic Diseases report of 1990.

21st Century

In August 2002, following an extensive strategic review process, IASO and IOTF merged to become a single entity capable of confronting the challenges posed by the global obesity epidemic in the 21st century. 

The newly incorporated IASO became a registered NGO in the WHO system when the IOTF’s work with the WHO was formalised.

The inaugural Stock Conference, so-named to commemorate a lifetime’s research by Dr. Mike Stock, was held in 2002. A series of annual 3-day meetings, this conference’s small interactive forum enables young investigators to become more proficient in their understanding of an important aspect of obesity research and links them with global leaders in the field.

In 2003, IASO helped to nurture and establish its largest regional component, the European Association for the Study of Obesity (EASO), by serving as the Secretariat, producing policy papers and organising its annual European Congresses on Obesity (ECO) which had been running since 1988. IASO also helped to establish EASO’s position on the European Platform on Obesity.​

A major educational programme was launched in 2003 by IOTF: SCOPE (Specialist Certification of Obesity Professionals in Education) aimed to recognise obesity specialists and enhance the quality of obesity education for medical professionals in Europe. The ‘E’ in SCOPE initially stood for Europe, but it was soon realised that the need for education extended far beyond that region alone.​

In 2004 IASO’s Executive Committee agreed to create a trading subsidiary, Obesity International Trading Ltd (OIT), to run the international programme of congresses and conferences. Registered as a company in the UK in January 2005, the first meeting organised in-house by OIT was the 15th ECO 2007 in Budapest.

In 2005 IASO spearheaded a new Global Alliance, made up of five principal medical non-governmental organizations formally linked to the WHO: the World Heart Federation (WHF), International Diabetes Federation (IDF), International Pediatric Association (IPA), International Union of Nutritional Sciences (IUNS) and IASO itself. The Alliance initiated the development of the first ever global action programme to address the issues surrounding the prevention of obesity and related chronic disease, with a particular focus on childhood obesity.

IASO introduced the International Journal of Pediatric Obesity (IJPO) in March 2006 under the editorship of Prof Louise Baur. The same year saw the launch of SCOPE’s online course, entirely evidenced based and complete with links to PubMed citations for each reference.  SCOPE is now used in Latin America and South Africa, with plans to develop and adapt it further for use in different geographic regions, and to broaden its offering for nurses, nutritionists/dieticians, pharmacists and fitness professionals.

2006 also marked the introduction of two biannual fora, organised by OIT, to engage private sector partners. The Obesity Expert Forum updates senior members of the pharmaceutical industry on topical initiatives and achievements, and facilitates the exchange of expertise on key issues facing those involved in tackling obesity and its co-morbidities. The Nutrition Discussion Forum creates a strategic platform for discussion between senior IASO members and senior nutritional industry representatives.

In 2007 IASO’s Education and Management TaskForce (EMTF) assumed responsibility for SCOPE, extending its reach to other parts of the world to cover Latin America, South Africa and the Middle East, Asia and Australasia, and Canada.

In 2011 IASO introduced a third journal, Clinical Obesity, edited by Professor Nicholas Finer with Dr Matt Sabin acting as Deputy Editor. The journal features high-quality translational and clinical research papers and reviews focussing on obesity and its co-morbidities.

In 2014 IASO underwent a rebrand.

The New Brand

World Obesity, and the strapline Knowledge Solutions Action are the new name and brand for IASO.

Why a new brand?

The obesity crisis is one of the biggest challenges of our time and it is more important than ever that there is strong and unified global action to tackle it. The name IASO – the International Association for the Study of Obesity – no longer reflects all that we do as an organisation. We are no longer simply focused on the study of obesity, but on bringing together and encouraging the very best thinking and practice in addressing the obesity crisis.

We believe the clarity and directness of World Obesity, our new name and brand, strengthens our ability to achieve our goals.

Our rebranding is also an opportunity to clarify two critical strands of our work – World Obesity Policy & Prevention (formerly IOTF- the International Obesity Task Force) and World Obesity Clinical Care (formerly EMTF- the Education and Management Task Force). Both strands have new and more explicit names (Policy & Prevention, and Clinical Obesity) that more accurately reflect the scope of their work and emphasise their pivotal role in the World Obesity family.


World Obesity Federation represents professional members of the scientific, medical and research communities from over 80 regional and national obesity associations. OIT continues to organise ICO, World Obesity’s global forum for scientific dialogue and intelligent, informed debate on obesity, as well as other meetings and conferences in the field of obesity and its related disciplines.

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