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SALT LAKE CITY -- Dieters take heart. The inability to maintain long-term weight loss after dieting may have more to do with hormonal changes than psychological or will power issues.
A new study reported in the New England Journal of Medicine that weight loss and dieting trigger a natural physical response that almost guarantees you will gain that weight back within a year, and probably with bonus poundage as well. The study suggests "that the high rate of relapse among obese people who have lost weight has a strong physiological basis and is not simply the result of the voluntary resumption of old habits.”
“The activation of this coordinated response in people who remain obese after weight loss supports the view that there is an elevated body-weight set point in obese persons, and that efforts to reduce weight below this point are vigorously resisted by the body, the study reported.
The researchers posit “that a disproportionate reduction in 24-hour energy expenditure persists in persons who have maintained a reduced body weight for more than one year” after the actual weight loss.
32.6 percent of American adults were overweight
27.6 percent were obese Utah:
34.7 percent of adults were overweight
23.0 percent were obeseSource:
Joseph Proietto, the lead researcher, said that “people that maintain weight loss do so because they work hard to do so. They weigh themselves regularly and they exercise a lot. If they stop, (the) weight comes back.
“Our results show that the changes are definitely there and that they appear to be a coordinated change to encourage weight regain," he added. "We do not know if the changes persist past one year, but I would guess that they do on the basis that most people regain weight.”
According to the study, “Body weight is centrally regulated, with peripheral hormonal signals … in the hypothalamus, to regulate food intake and energy expenditure.”
Dieting or reducing caloric intake throws a monkey wrench into the equation and causes hormones to go wild. The imbalance could extend for several years, based on anecdotal evidence, or even indefinitely, but Proietto stresses he does not know for sure and more research needs to be done.
What this means in terms of drug development is that “We desperately need drugs, not to lose weight, but to keep it off”, said Proietto.
Weight loss can be achieved with any program or diet. Weight maintenance must have more than just lifestyle advice, it will require drugs/hormones to control hunger.
–Joseph Proietto
“Weight loss can be achieved with any program or diet. Weight maintenance must have more than just lifestyle advice, it will require drugs/hormones to control hunger,” Proietto said.
Some people believe that natural dietary supplements are beneficial for weight loss. Not so, says Proietto. “Most natural remedies for obesity are there to make the manufacturer rich. They generally have few side effects, largely because they don’t do anything. Most require the patient to also follow a diet, which is why they work. Some others have caffeine and possibly nicotine. None have been properly tested.”
According to the researchers, “successful management of obesity will require the development of safe, effective, long-term treatments to counteract these compensatory mechanisms (to stabilize the hormones) and reduce appetite. Given the number of alterations in appetite-regulating mechanisms that have been described so far, a combination of medications will probably be required.”
They added, “Several such combinations are undergoing evaluation, but none have been approved by the Food and Drug Administration.”
The study, titled “Long-Term Persistence of Hormonal Adaptations to Weight Loss,” was conducted by Australian researchers Priya Sumithran, Luke A. Prendergast, Elizabeth Delbridge, Katrina Purcell, Arthur Shulkes, Adamandia Kriketos and Joseph Proietto.
It was funded with a project grant from the National Health and Medical Research Council, a scholarship from the Endocrine Society of Australia, a Shields Research Scholarship from the Royal Australasian College of Physicians and funding from the Sir Edward Dunlop Medical Research Foundation. Mel Borup Chandler lives in Southern California and writes on science, technological breakthroughs and medicine. His email is mbccometator@roadrunner.com.
