Randomized Clinical Trial to Assess the Efficacy of a Mobile Application to Help in Weight Loss Before Bariatric Surgery: the VAMOS Project (Virtual Accompaniment for Morbid Obesity Surgery)

Morbid obesity is considered the great epidemic of our century. It is regarded as the first non-traumatic cause of death in the western population and it is also progressively beginning to affect developing countries. The latest epidemiological studies estimate that in Spain more than 15% of the population has overweight and about 5% has morbid obesity.

Obesity treatment is multidisciplinary, from lifestyle and dietary changes to surgery. Amongst the different available treatments, bariatric surgery is the only cost-effective in patients with morbid obesity. Bariatric surgery provides better results compared to both pharmacological treatments (which are less available and less effective) and lifestyle changes. Furthermore, as well as weight loss, it guarantees a better control of comorbidities, reducing the risk of cardiovascular disease, morbidity and mortality, improving quality of life.

Although surgery is the best treatment option, patient commitment is necessary to achieve satisfactory results. Obtaining patient's comprehension of the importance of healthy lifestyle and equilibrated diet alongside with surgical information is generally difficult. Patient's concern needs to be constantly stressed out. The ongoing protocols that include preoperative meetings with surgeons, endocrinologists and nutritionists have been proved as insufficient, especially during the Covid-19 pandemic, when presential visits were reduced or cancelled.

Preoperative optimization with a healthy lifestyle and a balanced diet few months before surgery potentially reduce intraoperative complications alongside with postoperative morbidity and mortality. Level of physical activity, diet and psychological stability could affect surgery's outcome for example reducing liver volume (up to 20%) and mesenteric fat. Also, an improvement in patient's preoperative satisfaction, anxiety and commitment to surgery have been suggested. Their impact on postoperative outcomes is unclear. There is lack of consensus on a standardized preoperative approach and goals. Many health care professionals worldwide strongly believe that preoperative optimization has an important impact on postoperative outcomes, but the evidence supporting this belief is mixed and most often retrospective. Although a positive relationship between self-monitoring behaviors (such as daily food intake diaries and regular self-weighing) and weight loss has been proved, additional instruction and behavioral intervention are needed. Besides weight loss, other factors such as adherence to self-monitoring of weight, recording food intake, increased physical activity could influence postoperative outcomes.

Even though official guidelines for an enhanced recovery (ERAS, Enhanced Recovery After Surgery) in bariatric surgery recommend patient information, education, counseling and preoperative weight loss, the efficacy of these measures has not been proved.