Not your fault! Hormones linked to weight regain
Any dieter knows that it's hard to keep off weight you've lost. Now a study finds that even a year after dieters shed a good chunk of weight quickly, their hormones were still insisting, "Eat! Eat! Eat!"
The findings suggest that dieters who have regained weight are not just slipping back into old habits, but are struggling against a persistent biological urge.
"People who regain weight should not be harsh on themselves, as eating is our most basic instinct," Joseph Proietto of the University of Melbourne in Australia, an author of the study, said in an email. The research appears in Thursday's issue of the New England Journal of Medicine.
Weight regain is a common problem for dieters. To study what drives it, Proietto and his colleagues enrolled 50 overweight or obese patients in a 10-week diet program in Australia. They wanted to see what would happen in people who lost at least 10 percent of their body weight. Ultimately, only 34 people lost that much and stuck with the study long enough for analysis.
The program was intense. On average, the participants lost almost 30 pounds during the 10 weeks, faster than the standard advice of losing 1 or 2 pounds a week. They took in 500 to 550 calories a day, using a meal replacement called Optifast plus vegetables for eight weeks. Then for two weeks they were gradually reintroduced to ordinary foods.
Despite counseling and written advice about how to maintain their new weights, they gained an average of 12 pounds back over the next year. So they were still at lower weights than when they started.
The scientists checked the blood levels of nine hormones that influence appetite. The key finding came from comparing the hormone levels from before the weight-loss program to one year after it was over. Six hormones were still out of whack in a direction that would boost hunger.
The dieters also rated themselves as feeling hungrier after meals at the one-year mark, compared to what they reported before the diet program began.
Experts not connected to the study said the persistent effect on hormone levels was not surprising, and that it probably had nothing to do with the speed of the weight loss.
People who lose less than 10 percent of body weight would probably show the same thing, though to a lesser degree, said Dr. George Bray of the Pennington Biomedical Research Center in Baton Rouge, La.
A key message of the study is that "it's better not to gain weight than to try to lose it," Bray said.
Why would a dieter's body rebel against weight loss? It's an evolutionary holdover from earlier times, when weight loss could threaten survival and reproduction, says Dr. Rudolph Leibel, an obesity expert at Columbia University in New York. So "it's not surprising at all" that our bodies would fight back for at least a year, he said. "This is probably a more or less permanent response."
People who lose significant weight not only gain bigger appetite but also burn fewer calories than normal, creating "a perfect storm for weight regain," Leibel said.
He said avoiding weight regain appears to be a fundamentally different problem from losing weight in the first place, and that researchers should pay more attention to it.
The study was supported by the Australian government, medical professional groups and a private foundation. Proietto served on a medical advisory board of Nestle, maker of Optifast, until last year.
More information: New England Journal of Medicine: http://www.nejm.org
©2011 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
- Appetite hormones may predict weight regain after dieting Sep 09, 2010 | not rated yet | 0
- Study shows why weight gain is inevitable May 09, 2006 | not rated yet | 0
- Study on fasting and dieting suggests why diets fail -- and why a weekly fast might work Mar 26, 2010 | not rated yet | 0
- Lose weight fast for lasting results, suggests new study May 06, 2010 | not rated yet | 0
- 'Yo-yo' effect of slimming diets explained Jan 12, 2011 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Classical and Quantum Mechanics via Lie algebras
Apr 15, 2011 I'd like to open a discussion thread for version 2 of the draft of my book ''Classical and Quantum Mechanics via Lie algebras'', available online at http://lanl.arxiv.org/abs/0810.1019 , and for the...
- More from Physics Forums - Independent Research
More news stories
Research shows that the earlier the age at which youth take their first alcoholic drink, the greater the risk of developing alcohol problems. Thus, age at first drink (AFD) is generally considered a powerful predictor of ...
Health 16 hours ago | not rated yet | 0
One quarter of British lawmakers believe there is an "unhealthy" drinking culture in the Houses of Parliament, according to a survey published on Friday.
Health 22 hours ago | not rated yet | 0
Researchers at the University of Cincinnati (UC) have found that the race and sex of study personnel can influence a patient's decision on whether or not to participate in clinical research.
Health 22 hours ago | not rated yet | 0
The processes to allow people to self-manage their own illness are not being used appropriately by health professionals to the benefit of their patients, new research suggests.
Health 23 hours ago | not rated yet | 0
Control of heart disease risk factors varies widely among outpatient practices, according to a study presented at the American Heart Association's Quality of Care and Outcomes Research Scientific Sessions 2013.
Health May 17, 2013 | not rated yet | 0
Big names in medicine are set to give an upbeat assessment of the war on AIDS on Tuesday, 30 years after French researchers identified the virus that causes the disease.
7 hours ago | 5 / 5 (1) | 0
For combat veterans suffering from post-traumatic stress disorder, 'fear circuitry' in the brain never rests
Chronic trauma can inflict lasting damage to brain regions associated with fear and anxiety. Previous imaging studies of people with post-traumatic stress disorder, or PTSD, have shown that these brain regions can over-or ...
8 hours ago | not rated yet | 0 |
(Medical Xpress)—What if the quality of your work depends more on your focus on the piano keys or canvas or laptop than your musical or painting or computing skills? If target users can be convinced, they ...
20 hours ago | 3.7 / 5 (3) | 0 |
The neural machinery underlying our olfactory sense continues to be an enigma for neuroscience. A recent review in Neuron seeks to expand traditional ideas about how neurons in the olfactory bulb might encode information about ...
19 hours ago | not rated yet | 0 |
(AP)—Twenty-three youths have died in the past nine days at initiation ceremonies that include circumcisions and survival tests, South African police said Friday.
May 17, 2013 | 5 / 5 (1) | 3
In 2008 researchers from the University of Southern Denmark showed that the drug thioridazine, which has previously been used to treat schizophrenia, is also a powerful weapon against antibiotic-resistant bacteria such as ...
17 hours ago | 3.7 / 5 (3) | 0 |