Background: Eating disorders are health problems that are particularly prevalent in adolescents and young adults. They are associated with considerable physical health and psychosocial morbidity, and increased risk of mortality. We set out to conduct a systematic review to determine their effect on physical fitness in the general population and on sport performance in athletes. Methods/Design: A systematic review of the relevant peer-reviewed literature was performed. For inclusion, articles retrieved from PubMed had to be published in English between 1977 and 2013. Wherever possible, methods and reporting adhere to the guidelines outlined in the PRISMA statement. Some additional studies were retrieved from among those cited in the reference lists of included studies and from non-electronic databases. Literature searches, study selection, method and quality appraisal were performed independently by two authors, and data was synthesized using a narrative approach. Results: Of the 1183 articles retrieved, twenty-nine studies met the inclusion criteria and were consequently analysed. The available data indicate that eating disorders have a negative effect on physical fitness and sport performance by causing low energy availability, excessive loss of fat and lean mass, dehydration, and electrolyte disturbance. Discussion: Although the paucity of the available data mean that findings to date should be interpreted with caution, the information collated in this review has several practical implications. First, eating disorders have a negative effect on both physical fitness and sport performance. Second athletics coaches should be targeted for education about the risk factors of eating disorders, as deterioration in sport performance in athletes, particularly if they are underweight or show other signs of an eating disorder, may indicate the need for medical intervention. However, future studies are needed, especially to assess the direct effect of eating disorders on sport performance.

Personalized cognitive-behavioural therapy for obesity (CBT-OB) is a new treatment that combines the traditional procedures of standard behavioural therapy for obesity (i.e., self-monitoring, goal setting, stimulus control, contingency management, behavioural substitution, skills for increasing social support, problem solving and relapse prevention) with a battery of specific cognitive strategies and procedures. These enable the treatment to be individualized, and to help patients to address the cognitive processes that previous research has found to be associated with treatment discontinuation, the amount of weight lost and long-term weight-loss maintenance. The treatment programme can be delivered at three levels of care, outpatient, day hospital and residential, and includes six modules, which are introduced according to the individual patient’s needs as part of a flexible, personalized approach. The primary goals of CBT-OB are to help patients to (i) achieve, accept and maintain healthy weight loss; (ii) adopt a lifestyle conducive to weight control; and (iii) develop a stable “weight-control mindset”. A randomized controlled trial has found that 88 patients suffering from morbid obesity treated with CBT-OB followed a period of residential treatment achieved a mean weight loss of 15% after 12 months, with no tendency to regain weight between 6 and 12 months. The treatment efficacy is also supported by data from a study assessing the effects of group CBT-OB delivered in a real-world clinical setting. In that study, 77 patients with morbid obesity who completed the treatment achieved 9.9% weight loss after 18 months. These promising results, if confirmed by future clinical studies, suggest that CBT-OB has the potential to be more effective than traditional weight-loss lifestyle-modification programmes.

Little is known about the treatment of adolescents with an eating disorder who are not underweight. Enhanced cognitive behaviour therapy (CBT-E) is a potential option as it is a treatment for adult patients with eating disorders of this type and it has been shown to be effective with adolescent patients who are underweight. The aim of the present cohort study was to evaluate the effects of CBT-E on non-underweight adolescents with an eating disorder. Sixty-eight adolescent patients with an eating disorder and a body mass index (BMI) centile corresponding to an adult BMI ≥ 18.5 were recruited from consecutive referrals to a community-based eating disorder clinic. Each was offered 20 sessions of CBT-E over 20 weeks. Three-quarters completed the full 20 sessions. There was a marked treatment response with two-thirds (67.6%, intent-to-treat) having minimal residual eating disorder psychopathology by the end of treatment. CBT-E therefore appears to be a promising treatment for those adolescents with an eating disorder who are not underweight.

Lifestyle modification based on behavior therapy is the most important and effective strategy to manage the metabolic syndrome. Modern lifestyle modification therapy combines specific recommendations on diet and exercise with behavioral and cognitive strategies. The intervention may be delivered face-to-face or in groups, or in groups combined with individual sessions. The main challenge of treatment is helping patients maintain healthy behavior changes in the long term. In the last few years, several strategies have been evaluated to improve the long-term effect of lifestyle modification. Promising results have been achieved by combining lifestyle modification with pharmacotherapy, using meals replacement, setting higher physical activity goals, and long-term care. The key role of cognitive processes in the success/failure of weight loss and maintenance suggests that new cognitive procedures and strategies should be included in the traditional lifestyle modification interventions, in order to help patients build a mind-set favoring long-term lifestyle changes. These new strategies raise optimistic expectations for an effective treatment of metabolic syndrome with lifestyle modifications, provided public health programs to change the environment where patients live support them.