Does Offering Patients Choice of Diet Improve Weight Loss?
A new study finds that allowing patients to choose a diet rather than being prescribed one doesn’t seem to aid weight-loss efforts.
To examine whether offering choice of diet improves weight loss, a team including researchers from the Durham Veteran Affairs Medical Center and Virginia Commonwealth University conducted a double-randomized preference trial of choice between 2 diets versus random assignment to a diet over 48 weeks. The authors randomized 200 patients with a body mass index (BMI) of at least 30 kg/m2 to either the choice or comparator diet groups, conducting the study at an outpatient clinic at a Veterans Affairs medical center.
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Choice participants received information about their food preferences and 2 diet options—low-carbohydrate diet (LCD) or low-fat diet (LFD)—before choosing, and were allowed to switch diets at 12 weeks. Comparator participants were randomly assigned to 1 diet for 48 weeks. Both groups received group and telephone counseling for 48 weeks. Only 2 diet options were provided, according to the authors, who note that results from this sample of older veterans may not be generalizable to other populations.
Overall, 61 (58%) of 105 choice participants chose the low-carbohydrate diet, with 44 (42%) opting for the low-fat diet. Five participants—3 of which initially chose the LCD and 2 that selected the LFD—switched diets at 12 weeks, and 87 completed measurements at 48 weeks. At the 48-week mark, the estimated mean weight loss was 5.7 kg in the choice group and 6.7 kg in the comparator group. Secondary outcomes of dietary adherence, physical activity, and weight-related quality of life were similar between groups at 48 weeks.
The study “shows that allowing patients to choose the diet they wish to follow was no more successful for their weight loss goals than assigning the patient a diet to follow,” says Stephanie B. Mayer, MD, MHSc, an assistant professor in the VCU division of endocrinology and metabolism, and a study co-author.
However, participants in both arms of the study were ultimately successful in losing weight, she says. As such, “it remains of critical importance for primary care physicians to gauge patient readiness for change, and to support and coach them in their dietary change efforts with appropriate goal setting and serial re-evaluation, irrespective of diet that is chosen or assigned.”
Mayer also suggests making frequent visits or telephone calls to ensure patient accountability, referring patients to a nutritionist fluent in the particular diet that is being followed, adding that “the structured group dynamic of patients united in a common goal of weight loss may also be helpful if available in the clinic setting.”
Primary care practitioners “should not offer a choice for the purpose of improving weight loss,” adds William S. Yancy Jr., MD, MHSc, a research associate in the Center for Health Services Research in Primary Care at the Durham VA Medical Center, and lead study author.
“There may be other reasons to offer a choice of diets,” he says, “but increasing weight loss success is not one of them, nor is improvement in adherence or weight-related quality of life.”
—Mark McGraw
Reference
Yancy W, Mayer S, et al. Effect of Allowing Choice of Diet on Weight Loss: A Randomized Trial. Ann Intern Med. 2015.