1. Patients struggle to stick to their diet when they choose a plan they like

Researchers say it's counterintuitive, but letting patients choose a diet plan based on personal preference may not help them lose weight. The results of a randomized trial are published in Annals of Internal Medicine.

Regardless of the approach, greater adherence to dietary recommendations is the best predictor of weight loss. Researchers hypothesized that letting patients choose a diet they like might help them adhere to a program and lose more weight than if they were assigned a diet by their physician. They randomly assigned 207 participants to one of two groups: choice or comparator. The choice participants were given the option of following a low-carbohydrate diet without calorie restriction or a low-fat diet combined with calorie restriction. The comparator group was randomly assigned a diet. Both groups were offered group and telephone counseling sessions throughout the 48-week study. At 12 weeks, choice participants were offered the opportunity to switch diets if they were unsatisfied with the option they chose, yet very few switched. Contrary to expectations, patients in the choice group lost less weight and reported less dietary adherence and weight-related quality of life than those who were prescribed a diet.

According to the researchers, these results suggest that choosing a diet based on food preferences may make it difficult for dieters to scale down on the amount that they eat. Future research should consider matching the most effective diet to an individual using other patient characteristics such as metabolic profile or even genetic profile.

2. Two systematic evidence reviews evaluate diagnostic methods and treatments for myalgic encephalomyelitits/chronic fatigue syndrome

Up to 2.5 million Americans suffer from myalgic encephalomyelitis (ME)/chronic fatigue syndrome (CFS), a debilitating multisystem condition characterized by chronic, disabling fatigue and other symptoms, including pain, sleep disturbance, neurologic and cognitive changes, motor impairment, and altered immune and autonomic responses. Because the condition is characterized exclusively by symptoms, physicians have wondered if the illness is "real." Articles published in this issue of Annals of Internal Medicine suggest that ME/CFS is prevalent and real. The following reviews were conducted as part of a larger report to inform a research agenda for the National Institutes of Health (NIH) 2014 Pathways to Prevention Workshop, which was established to identify research gaps in selected scientific areas.

No diagnostic methods proven effective for diagnosing ME/CFS

The diagnosis of ME/CFS is based on nine sets of clinical criteria that attempt to distinguish it from other conditions that also present with fatigue. Currently, there is no consensus about which, if any, of these clinical criteria should be considered the reference standard. Researchers reviewed 44 published studies to evaluate and compare methods for diagnosing ME/CFS. They found that none of the current diagnostic methods have been adequately tested to determine how well they differentiate patients with ME/CFS from patients with other conditions. The researchers recommend more definitive studies in broader populations to address the research gaps.

Counseling therapies and graded exercise may improve fatigue and function in some patients

Patients with ME/CFS experience a broad range of symptoms. Currently there is no FDA-approved treatment for the condition, but many medications have been used off-label. Researchers reviewed 35 published studies to determine the benefits and harms of treatments for adults with ME/CFS. The researchers found limited evidence indicating that rinatolimod improved measures of exercise performance compared with placebo in patients with severe debilitation from ME/CFS. Low to moderate strength evidence showed that counseling, behavior therapies, and graded exercise therapy improved measures of fatigue, function, global improvement, and work impairment. The researchers caution that these treatments have not been adequately tested in broader patient populations that may meet more specific case definitions of ME/CFS. More research is needed to evaluate these and other treatments.