Health at Every Size

The first principle of HAES is the acceptance of size diversity. The tenant involves not pathologizing or idealizing any weight or body size.[5]

The second principle of HAES is to “support health practices that improve and equalize access to information, service, and personal practices that improve human well-being…” This a sociological lens which can help professionals to inform their treatment of a patient.[5]

The third principle of HAES asks professionals to acknowledge biases and to provide services which are informed by the social impacts a patient may be experiencing. Weight stigma is influenced by many factors including  socio-economic status, race, gender, sexual orientation, age, and other identities. HAES principle 3 asks that providers create a supportive environment.[5]

Principle 4 is focused on diet choices. Also impacted by the availability of food and individual patient experience the fourth principle is to “promote flexible, individualized eating based on hunger, satiety, nutritional needs, and pleasure, rather than any externally regulated eating plan focused on weight control.”[5]

Principle 5 is focused on movement. Similar to the other principles, HAES promotes an individualized approach to movement stating "support physical activities that allow people of all sizes, abilities, and interests to engage in enjoyable movement, to the degree that they choose."[5]

Many studies have established the short term weight loss caused by dieting.[6][7] There is, however, a large portion of research that also establishes that most weight lost will be regained.[8][9][10][11][12][13][14][15] As a panel of obesity researchers convened by the Institute of Medicine summarized: ‘Studies paint a grim picture: those who complete weight-loss programs lose approximately 10% of their body weight, only to regain two-thirds of it back within a year and almost all of it back within 5y."[16]

There has been some push towards a health centered approach which focuses on improving healthy behaviors which can result in improved health and well-being.[17][18][19] This approach can be particularly effective with comorbidities associated with the insulin resistance syndrome (eg hypertension, dyslipidemias and hyperinsulinemia). A health-centered approach addresses many of the health conditions common in obese patients directly, rather than relying on weight loss as a pre-condition.[20]

The book "Health at Every Size" written by Linda Bacon overviews her scientific work on HAES.[21] The book describes a publication which compared a traditional weight loss approach to a non-diet wellness approach.[20] A total of 78 participants were enrolled in the study. Participants were overweight females who had a history of chronic dieting with a BMI of 30-45. Participants were randomly split into a diet group and a non-diet group and participated in 24 weekly classes of 90 minutes. After this period there was an after care program that met once a month and was optional where no new information was presented.

The diet group was presented with traditional weight loss approach including the LEARN Program for Weight Control manual.[22] In the non-diet group there were "five aspects to the treatment program: bodyacceptance, eating behavior, activity, nutrition, and social support. Initial treatment focused on enhancing body-acceptance and self-acceptance, and subjects were supported in leading as full a life as possible, regardless of their body weight or whether they succeed at weight control."[20] The Non-diet participants were given a written manual which later became Linda Bacon's book "Health at Every Size."[21]

Interestingly, "by mid-treatment, 13 subjects had dropped out of the diet group (33%) compared to three (8%) who dropped out of the non-diet group. By post-treatment, an additional three subjects dropped out of the diet group (total drop-outs 41%), while no additional subjects dropped out of the nondiet group (total remained at 8%)."[20] The diet group did lose weight (average 5.9kg) while the non-diet group did not have any notable change. However, "both groups significantly improved in total cholesterol, LDL, triglycerides and systolic blood pressure" throughout the study. The weight loss in the diet group was not statistically significant compared to the non-diet group. There was no statistically different energy expenditures between groups at 1 year (32.1% increase for the non-diet and 30.4% increase in the diet group). For mental health, "Participants in the non-diet group showed a significant improvement on the Rosenberg Self-Esteem Inventory (RSE)" whereas the participants in the diet group initially showed improvements but they were not sustained over the 1 year.

The study concluded that the HAES approach produced similar results at 1 year as the traditional weight loss approach did. Despite not losing weight, the non-diet group lowered their risk factors for cardiovascular disease as much as the diet group showing that weight loss is not a prerequisite for lowering risk factors. Notably the non-diet group did not suffer from the dropout rate that the diet group faced. This facet has not been widely reported in other literature about weight loss. The self esteem of participants was also very different between groups. In the non-diet group almost all participants agreed to the statement "The program has helped me feel better about myself" whereas only half of participants in the diet group agreed. And despite the weight loss many of the diet group participants reported that they felt that they had "failed the program." The authors state, "the principle finding of this study was that a non-diet approach, in the absence of weight loss, can produce similar health improvements, while at the same time effectively minimizing the attrition problems common to participants in diet programs."[20]

There is a considerable amount of evidence that being overweight is associated with increased all-causes mortality, and significant weight loss (>10%), using a variety of diets, improves or reverses metabolic syndromes and other health outcomes associated with overweight and obesity.[23][24][25][26][27] For more information see obesity. The classification of obesity as a disease is controversial. The Council on Science and Public Health (CSPH) released their report in 2013 entitled “Is Obesity a Disease?” which concluded that there was not enough evidence to classify obesity as a pathology.[28] A classification of obesity as a disease relies on the BMI which may be flawed. "An analysis of 97 studies covering 2.88 million people, published in the Journal of the American Medical Association in January 2013, found that people who were termed “overweight” were actually 6 percent less likely to die than those of so-called “normal weight” over an identical time period."[29] In light of this inconclusive evidence the decision to classify obesity as a disease was voted on and passed by the American Medical Association.

The obesity paradox is the observation that as BMI increases instances of hypertension, heart disease and diabetes go up. However, mortality from these diseases go down.[30] This may indicate that BMI is a flawed system that should be replaced by an alternative measure. The use of biomarkers instead of weight proposed by HAES may be useful in treating patients.