University of California, Davis, January 24, 2011 - Dieting and other weight-loss efforts may unintentionally lead to weight gain and diminished health status, according to two researchers, including a UC Davis nutritionist, whose new study, Weight Science:Evaluating the Evidence for a Paradigm Shift, appears in the Jan. 24 issue of the Nutrition Journal, an online, open-access scientific journal.
Rather than focusing on weight loss, the researchers recommend that people focus on improving their health status.
In the new study, co-authors Linda Bacon, an associate nutritionist in the UC Davis Department of Nutrition, and Lucy Aphramor, an NHS specialist dietician and honorary research fellow at the Applied Research Centre in Health and Lifestyle Interventions at Coventry University, England, cite evidence from almost 200 studies.
"Although health professionals may mean well when they suggest that people lose weight, our analysis indicates that researchers have long interpreted research data through a biased lens," Bacon said. "When the data are reconsidered without the common assumption that fat is harmful, it is overwhelmingly apparent that fat has been highly exaggerated as a risk for disease or decreased longevity."
Bacon noted that the study findings do not support conventional ideas (or popular myths):
Myth = Weight loss will prolong life.
Myth = Anyone can lose weight and keep it off through diet and exercise.
Myth = Weight loss is a practical and positive goal.
Myth = Weight loss is the only way overweight and obese people can improve their health.
Myth = Obesity places an economic burden on society.
"The weight-focused approach does not, in the long run, produce thinner, healthier bodies," said Bacon.
"For decades, the United States' public health establishment and $58.6 billion-a-year weight-loss industry have focused on health improvement through weight loss," she said. "The result is unprecedented levels of body dissatisfaction and failure in achieving desired health outcomes. It's time to consider a more evidence-based approach."
Aphramor added: "It's the unintended negative consequences that are particularly troubling, including guilt, anxiety, preoccupation with food and body shape, repeated cycles of weight loss and gain, reduced self esteem, eating disorders and weight discrimination."
Concluding that the weight-focused approach to health is unsupported by the scientific evidence and has in fact been detrimental and costly, Bacon and Aphramor suggest the health care community should adopt what they say is "a more ethical, evidence-based approach toward public health nutrition" -- one that instead encourages individuals to concentrate on developing healthy habits rather than on weight management.
The researchers stress that evidence shows that changing health behaviors can sustainably improve blood pressure, blood lipids, self-esteem, body image, and other indicators of health and well-being, independent of any weight change and without the negative aspects of weight-focused approaches. While weight loss may result, the goal is self-care rather than weight loss, they say. This weight-neutral practice has become known as Health at Every Size.
"It is clear from our review of the data that body weight is a poor target for public health interventions," Bacon said. "Instead, the health care community should shift its emphasis from weight-management to health-improvement strategies, for the well-being of people of all sizes."
Bacon is the author of the 2010 book, "Health at Every Size: The Surprising Truth About Your Weight," based on previously published research. She also is the founder of Health at Every Size Community Resources.
Financial Disclosure: Aphramor received financial support for this study through a West Midlands Nurses, Midwives and Allied Health Professions research training award. Bacon and Aphramor are both Health at Every Size practitioners and sometimes receive financial compensation for writing and speaking on this topic.