In 2021, The Obesity Society (TOS), first known as NAASO, will be 40 years old. Happy birthday! This seemed an appropriate time to stop and record some of the events that led up to formation of the Society. As obesity became more prominent in the public eye following World War II, a group of physicians who were providing treatment for obesity, often in the form of what were called “Rainbow Diet Pills,” formed a professional clinical society on August 7, 1950, called the National Glandular Society, which changed its name to the American Society of Bariatric Physicians on August 25, 1972. This was the first American society related to obesity in this country. Its meetings were usually sponsored by the drug companies that were providing Rainbow Pills to bariatric physicians. On August 10, 2015, the American Society of Bariatric Physicians changed its name again to the Obesity Medicine Association.

The late 1960s and 1970s were important for obesity. The Association for the Study of Obesity (ASO) was founded in London in 1967 ((1)), and then it held a 1-day Symposium on Obesity in London in 1968 ((2)). This provided an excellent model for a national society focused on the scientific problem of obesity ((1)). The late 1960s saw many deaths associated with widespread use of Rainbow Pills. These deaths caught the attention of the US Government, and in 1968, a Senate Select Committee of the US Congress was empaneled to hold hearings on alleged misuse of these medications ((3)). In addition, 1968 was also the year that the US Congress approved formation of the John E. Fogarty International Center at the NIH. Because obesity was already recognized as a public health problem, even when its prevalence in 1962 was only 14%, The Fogarty Center asked Dr. George Bray to organize an international meeting, which was held at NIH on October 1 to 3, 1973 ((4)). This was followed by the First International Congress on Obesity in 1974 in London and a Second International Congress organized by Dr. Bray in Washington, DC, in 1977 ((5)). The funding of the Obesity Center in New York under the direction of Theodore van Itallie in 1975 further increased interest in forming a North American Association for the Study of Obesity (NAASO).

Table 1 provides a timeline for the early years of NAASO. Discussions between Dr. Bray and Dr. John Brunzell that occurred during Nutrition Committee meetings of the American Heart Association in 1979 to 1980 led to the informal organization of NAASO, which was founded in 1981 by Dr. Bray along with Dr. Judith Stern, Dr. John Brunzell, Dr. M.R.C. Greenwood, and Dr. C. Wayne Callaway. Of these five founders, three were clinicians and two basic scientists, which reflected the composition of the Society over the years to come.

TABLE 1. Timeline for the early history of NAASO Year Source Event 1973 4 Fogarty International Center Conference on Obesity, Bethesda, Maryland. 1977 5 2nd International Congress of Obesity in Washington, DC. 1980 George Bray solicits interest in forming North American Association for the Study of Obesity (NAASO) with urging from John Brunzell. 1981 George Bray founds NAASO with John Brunzell, C. Wayne Callaway, M.R.C. Greenwood, and Judith Stern. 1981 Vassar College selected as site for 1st NAASO meeting in 1982. 1981 Conference Support grant for a Conference on Methods for Characterizing Human Obesity submitted to NIH with C. Wayne Callaway as principal investigator. 1982 6 NAASO appoints John Brunzell and M.R.C. Greenwood to join Roger Pilkington from the UK on an International Publication Committee for the International Journal of Obesity. 1982 7 1st NAASO meeting on “Types of Obesity: Animal Models and Clinical Applications” was held at Vassar College on October 17 to 19, 1982. M.R.C. Greenwood hosted the meeting (Figure 1). 1983 2nd NAASO business meeting held at the 4th International Congress on Obesity in New York City. Officers elected were Barbara Hansen, President; Judith Stern, Secretary; and Anne Sullivan, Treasurer. “Incorporation began.” 1984 3rd NAASO meeting held in Seattle at the University of Washington with John Brunzell as host and a theme of “Exercise in Obesity.” 1984 8 Proceedings from the NIH-sponsored conference at the 1st NAASO meeting published in the International Journal of Obesity. 1985 4th NAASO meeting organized by Barbara Hansen was held in Toronto in conjunction with the American Diabetes Association. 1986 5th NAASO business meeting held in Jerusalem in conjunction with the 5th International Congress. 1987 6th NAASO meeting held in Boston with George Blackburn and Robin Kanarek as organizers and Blackburn’s 1st Harvard Post-Graduate Course on Obesity. 1988 7th NAASO meeting held in Banff, Canada, with Henry Koopmans as organizer. 1989 8th NAASO meeting held in Bethesda, Maryland, with Richard Atkinson as organizer.

Shortly after its organizational founding, NAASO was asked to provide members to a joint Publication Committee with the British ASO to select the next editor of The International Journal of Obesity (IJO) ((6)). Drs. Brunzell and Greenwood were named as the NAASO members of this Committee, and Roger Pilkington acted as the ASO contact. This joint ASO/NAASO Publication Committee chose Dr. Per Bjorntorp to replace Drs. Alan Howard and Bray as The International Journal of Obesity editors.

In 1981, Dr. Greenwood agreed to host the foundational meeting of NAASO at Vassar. The title of this meeting was “Types of Obesity: Animal Models and Clinical Applications” ((7)). Also in 1981, Dr. Callaway, who was on leave from Mayo Clinic while serving at the National Institutes of Health, spear-headed the request for a Conference Grant on “Methods of Characterizing Human Obesity,” which included 12 presentations ((8)). When the grant was funded, announcements of the meeting were circulated, and abstracts submitted. The planning committee, consisting of Drs. Bray, Greenwood, and Calloway, began meeting in early 1982 to select speakers and to review the 37 abstracts of scientific work that had been submitted. The NAASO meeting was attended by more than 150 people, presaging a society that has grown to have more than 2,000 members. Figure 1 is the front cover of the first NAASO meeting ((7)).

Front cover of the program for the 1st North American Association for the Study of Obesity (NAASO) meeting in 1982

The Fourth International Congress on Obesity took place in 1983 in New York and was chaired by Dr. Jules Hirsch and Dr. Theodore van Itallie. In conjunction with this meeting, NAASO held a second business meeting, during which Dr. Barbara C. Hansen was chosen as the first President, Judy Stern as Secretary, and Anne Sullivan (later Kessler) as Treasurer, replacing George Bray as Chairman and Founder, together with other cofounders. Figure 2 shows the five founders and the first President. Drs. Kenneth D. and Barbara Hansen prepared the organizational articles of incorporation for establishing NAASO as a 501c3 charitable organization. Dr. Brunzell agreed to host the third NAASO meeting at the University of Washington in Seattle on October 6 to 7, 1984, which focused on the role of exercise in obesity. The fourth NAASO meeting was organized by Dr. Barbara Hansen as a Joint Conference of the American Diabetes Association and NAASO, titled “Obesity and Non-insulin Dependent Diabetes Mellitus” in Toronto, Canada, in October 1985. Annual meetings of NAASO have generally been held thereafter.

The Obesity Society founders. (Top row) George A. Bray, MD (1931-), John D. Brunzell, MD (1937-2015), and C. Wayne Callaway, MD (1941-2019). (Bottom row) M.R.C. Greenwood, PhD (1943-), Judith S. Stern, ScD, RD (1943-2019), and Barbara C. Hansen, PhD

As interest in obesity expanded, NAASO realized that another journal was needed, and Obesity Research was established in 1993 with Dr. Bray as its first editor. In 2005, the Society journal changed its name from Obesity Research to simply Obesity.

The words “North American” were initially included in the NAASO name to provide a home for Canadian and Mexican scientists with an academic interest in obesity. NAASO changed its name to The Obesity Society (TOS) in 2005. Shortly thereafter, Obesity Canada and the Canadian Association of Bariatric Physicians and Surgeons were founded in 2006, reflecting the expanding community interested in obesity in North America. Some of the research highlights during the history of TOS are summarized in Table 2. In 2021, TOS is moving toward the ripe age of 40 years. Happy birthday with many more to come!

TABLE 2. TOS research highlights Discovery Impact Identification of leptin and leptin receptors Advanced understanding of physiology of body weight regulation Development of doubly labeled water technology for EE assessment Assessment of EE in free-living individuals Recognition in 1980s of increase in obesity prevalence in US and across globe Identification of a major global public health challenge Link between adipose tissue and inflammation Advanced understanding of pathophysiologic mechanisms by which obesity produces morbidity and mortality Recognition of the defense of fat mass Advanced understanding of the defense of body weight and the difficulty facing attempts at weight loss and weight loss maintenance Laparascopic bariatric surgery procedures Safe and effective long-term weight loss that is widely accessible with proven reduction in mortality, morbidity and health costs Understanding physiology of GLP-1 and developing the peptide as a pharmacologic agent Safe and effective treatment for diabetes, obesity, and cardiovascular disease prevention Obesity increases risk for adverse COVID-19 outcomes Underscoring the need to take obesity treatment seriously Brown fat can occur in human adults New target for therapy Microbiome is important in risk for obesity New target for therapy

The authors declared no conflict of interest.