How many times do we have to say it: Diets don't work, lifestyle changes
do.

In oups.com,
stated
| http://www.infozine.com/news/stories...View/sid/5113/
|
|
| Wednesday, January 05, 2005 :: infoZine Staff :: page views
| Study Finds That Adherence to Diet, Not Type of Diet, More Important
| Factor for Losing Weight A comparison of four popular diet plans finds
| that the key to losing weight may not be which diet plan a person
| picks, but sticking with the plan that is chosen.
|
| HealthChicago, IL - Journal of the American Medical Association - The
| study, in the January 5 issue of JAMA, also found that popular diets
| can be effective for modest weight loss and reducing several cardiac
| risk factors, but overall adherence rates were low.
|
| Popular diets have become increasingly prevalent and controversial,
| according to background information in the article. Many popular plans
| depart substantially from mainstream medical advice, and the
| effectiveness and safety of these diets have been questioned. Data
| regarding the relative benefits, risks, effectiveness, and
| sustainability of popular diets have been limited.
|
| In this one year study, Michael L. Dansinger, M.D., of Tufts-New
| England Medical Center, Boston, and colleagues assessed adherence
| rates and the effectiveness of four popular diets for weight loss and
| cardiac risk factor reduction. The diets and their principle weight
| loss strategies we Weight Watchers (restriction of portion sizes
| and calories); Atkins (minimize carbohydrate intake without fat
| restriction); Zone (modulate macronutrient balance and glycemic load);
| and Ornish (restrict fat).
|
| This trial included 160 overweight or obese adults aged 22 to 72
| years, with known hypertension, dyslipidemia (high cholesterol), or
| fasting hyperglycemia (high blood sugar). Participants were enrolled
| starting July 18, 2000, and randomized to the diet groups until
| January 24, 2002. Forty participants were assigned to each of the
| diet plans. After 2 months of maximum effort, participants selected
| their own levels of dietary adherence.
|
| Assuming no change from baseline for participants who discontinued the
| study, the researchers found that average weight loss at 1 year was
| 4.6 lbs. for Atkins (21 [53 percent] of 40 participants completed),
| 7.1 lbs. for Zone (26 [65 percent] of 40 completed), 6.6 lbs. for
| Weight Watchers (26 [65 percent] of 40 completed), and 7.3 lbs. for
| Ornish (20 [50 percent] of 40 completed). Greater effects were
| observed in study completers. Each diet significantly reduced the
| low-density lipoprotein/high-density lipoprotein (HDL) cholesterol
| ratio by approximately 10 percent with no significant effects on
| blood pressure or glucose at 1 year. Amount of weight loss was
| associated with self-reported dietary adherence level but not with
| diet type.
|
| For each diet, decreasing levels of total/HDL cholesterol, C-reactive
| protein, and insulin were significantly associated with weight loss
| with no significant difference between diets.
|
| "...all 4 diets resulted in modest statistically significant weight
| loss at 1 year, with no statistically significant differences between
| diets," the authors write. "In each diet group, approximately 25
| percent of the initial participants sustained a 1-year weight loss of
| more than 5 percent of initial body weight and approximately 10
| percent of participants lost more than 10 percent of body weight."
|
| "...we found that a variety of popular diets can reduce weight and
| several cardiac risk factors under realistic clinical conditions, but
| only for the minority of individuals who can sustain a high dietary
| adherence level. Despite a substantial percentage of participants who
| could sustain meaningful adherence levels, no single diet produced
| satisfactory adherence rates and the progressively decreasing mean
| adherence scores were practically identical among the 4 diets. The
| higher discontinuation rates for the Atkins and Ornish diet groups
| suggest many individuals found these diets to be too extreme. To
| optimally manage a national epidemic of excess body weight and
| associated cardiac risk factors, practical techniques to increase
| dietary adherence rates are urgently needed," the authors write.
|
| "One way to improve dietary adherence rates in clinical practice may
| be to use a broad spectrum of diet options, to better match individual
| patient food preferences, lifestyles, and cardiovascular risk
| profiles. Participants in our study were not allowed to choose their
| dietary assignment; however we suspect adherence rates and clinical
| improvements would have been better if participants had been able to
| freely select from the 4 diet options. Our findings challenge the
| concept that 1 type of diet is best for everybody and that alternative
| diets can be disregarded. Likewise, our findings do not support the
| notion that very low carbohydrate diets are better than standard
| diets, despite recent evidence to the contrary," the researchers
| write.
|
| JAMA Editor's Note: This study was supported by grants from the
| General Clinical Research Center via the National Center for Research
| Resources of the National Institutes of Health (NIH); by a grant from
| the NIH; a contract from the U.S. Department of Agriculture; and a
| contract from the Human Metabolic and Genetics Core Laboratory of the
| Boston Obesity Nutrition Research Center program. Dr. Dansinger was
| supported by a grant from the Agency for Healthcare Research and
| Quality.
|
| JAMA Editorial: The Dietary Approach To Obesity - Is It The Diet Or
| The Disorder?
|
| In an accompanying editorial, Robert H. Eckel, M.D., of the University
| of Colorado at Denver and Health Sciences Center, Aurora, Colo.,
| discusses the findings by Dansinger and colleagues that no one diet
| plan was found most effective for weight loss.
|
| "It seems plausible that for maintenance of reduced body mass, the
| right diet needs to be matched with the right patient. Ultimately, a
| 'nutrigenomic' approach most likely will be helpful. At present, there
| are no data to help clinicians practicably match a diet to an
| individual patient's 'diet response genotype.' Even beyond this
| consideration, and arguably more important, once weight loss of more
| than several kilograms from baseline weight occurs, a substantial
| step-up in the amount of physical activity and conscientious
| monitoring as part of a more comprehensive behavior modification
| appear particularly important, and likely are much more relevant
| adaptations than the macronutrient composition of the diet."
|
| "Arguably, the best treatment of obesity is prevention by careful
| dietary monitoring and lifestyle and choices, along with regular
| physical activity. Once overweight or obesity develops, however, the
| best existing evidence points toward heeding the recently released
| joint lifestyle recommendations of 3 professional organizations: the
| American Cancer Society, the American Diabetes Association, and the
| American Heart Association, in which the recommended macronutrient mix
| is built on evidence that higher intake of fruits and vegetables,
| whole grains, and fish are associated with reduced incidences of
| diabetes mellitus, cancer, heart disease, and stroke. Although this
| dietary approach may lead to only modest weight changes, similar to
| the popular diets evaluated by Dansinger et al, physicians and other
| health care professions should teach obese patients that both quality
| and quantity of the diet are important, and that sustained weight
| loss may well be possible with the addition of physical activity and
| behavioral change strategies to a modest but persistent caloric
| restriction-the 'Low Fad' approach," Dr. Eckel concludes.