Background: Obesity is a prevalent multifactorial disease worldwide and has become a significant public health concern. The latest data from the 2022 Catalonia Health Survey show that 56.2% of men and 43.7% of women are overweight or obese, and 39% of children aged 6 to 12 years have excess weight. Excess adiposity poses a health risk as it is associated with various chronic diseases such as type 2 diabetes mellitus, hypertension, and dyslipidaemia, all of which affect quality of life and increase mortality risk.

Hypothesis: The Energy2MOB obesity management programme in Berguedà is a group-based intervention incorporating nutrition education and physical activity. It aims to reduce excess body weight and the risk of chronic diseases, including type 2 diabetes mellitus, dyslipidaemia, and hypertension, through a multicomponent approach that enhances dietary habits, physical activity, and emotional eating regulation.

Objectives

• Assess the effectiveness of the Energy2MOB programme in reducing body weight by 5-10% among adults with obesity in the Berguedà health region.
• Measure lifestyle modifications, including dietary habits, physical activity, and emotional eating.

Methodology: A randomised clinical trial with two groups (control and intervention) over one year, including individuals aged 18-65 years in the Berguedà health region with overweight grade II (BMI 27-30 kg/m²) or obesity (BMI 30-40 kg/m²). Exclusion criteria include significant language barriers, previous bariatric surgery, moderate to severe cognitive impairment, and severe psychiatric disorders preventing participation in sessions. Participants must attend at least 80% of the programme.

Measurements

• Sociodemographic factors: sex, age, education level, marital status, employment status.
• Lifestyle factors: alcohol and tobacco use, dietary habits, physical activity, emotional eating, health-related quality of life.
• Anthropometric parameters: body weight, height, BMI, waist circumference.
• Blood pressure, medication use, biochemical parameters (fasting glucose, glycated haemoglobin, lipid profile, liver and kidney function markers, C-reactive protein).

Statistical Analysis: Accepting an alpha risk of 0.05 and a statistical power above 0.8 in a bilateral contrast, 68 subjects per group are required to detect a difference of at least 2.5 kg. A common standard deviation of 4.77 is assumed, with an estimated 15% dropout rate. Sample size calculations were performed using GRANMO version 8.0 (https://www.datarus.eu/ca/aplications/granmo/; consulted in November 2024).

Expected Outcomes, Applicability, and Relevance: This study aims to generate scientific evidence on the effectiveness of multicomponent group-based interventions focused on improving nutrition, physical activity, and psychological well-being in obesity and chronic disease management. It seeks to create an environment that facilitates behavioural changes, leading to weight reduction and improved quality of life. The findings will also contribute to the development of a practical guide for addressing excess weight in primary healthcare settings.

Keywords (maximum 6): Adult obesity, primary health care, group interventions, dietary interventions, multicomponent interventions, Mediterranean diet.

BACKGROUND AND CURRENT STATE OF THE TOPIC Obesity is a chronic, complex, and prevalent disease worldwide, posing a significant public health concern with high socio-economic costs. The World Health Organization (WHO) defines it as an abnormal or excessive accumulation of fat that impairs health, promotes medical complications, and reduces life expectancy.

Recent studies indicate that obesity prevalence has risen in recent years and is projected to continue increasing. According to a recent study by the Carlos III Health Institute in collaboration with the Spanish Agency for Food Safety and Nutrition (AESAN) and regional health services, 55.8% of adults are overweight (63.7% of men and 48.4% of women), and 18.7% have obesity (19.3% of men and 18.0% of women). Among children and adolescents, 10.7% have obesity, and 30% are overweight. More specifically, the 2022 Catalonia Health Survey reports that half of the population aged 18-74 years has excess weight, including overweight and obesity, with 56.2% of men and 43.7% of women affected. Among children aged 6-12 years, nearly 39% have excess body weight, with 25.2% classified as overweight and 13.7% as obese.

There is no doubt that modern society fosters an obesogenic environment, promoting sedentary lifestyles and unhealthy diets dominated by processed foods. However, additional factors predispose individuals to excess weight even without exposure to these obesogenic influences. Obesity is a multifactorial disease, involving both intrinsic (non-modifiable) factors such as genetics and physiological causes and extrinsic (modifiable) factors such as environmental, psychological, social, economic, and political influences.

Physiopathologically, obesity is characterised by chronic low-grade inflammation due to adipose tissue dysfunction caused by excessive and/or abnormal fat accumulation. Excess adiposity is a major health risk as it is associated with a broad range of chronic diseases, including cardiovascular disease, type 2 diabetes mellitus, certain cancers, mental health disorders, chronic kidney disease, musculoskeletal complications, respiratory diseases, and non-alcoholic fatty liver disease (NAFLD). Addressing this issue with evidence-based solutions is urgent and a public health priority.

Expert groups, including the National Institutes of Health, WHO, the Academy of Nutrition and Dietetics, and the Spanish Society for the Study of Obesity (SEEDO), recommend a 5-10% reduction in initial body weight over six months to achieve health benefits and manage obesity-related comorbidities. Such weight loss is associated with reductions in body mass index (BMI), waist circumference, and fat mass, alongside significant improvements in glucose levels, lipid profile, and blood pressure. Consequently, obesity reduction strategies offer substantial benefits for chronic disease management, particularly type 2 diabetes mellitus, dyslipidaemia, and hypertension.

Beyond its impact on physical health, obesity also affects emotional, psychological, and social well-being. Weight-related stigma, discrimination, and bias contribute to decreased quality of life and increased obesity-related comorbidities. Current scientific evidence highlights that body weight regulation is not solely under voluntary control, as biological, genetic, and environmental factors play fundamental roles in obesity development and maintenance. Ineffective weight loss outcomes, insufficient multidisciplinary coordination, a lack of human and economic resources for obesity management, and societal misperceptions about obesity-particularly in lower socioeconomic groups-contribute to the overburdening of healthcare systems, preventing comprehensive and high-quality patient care.

Therefore, obesity treatment must adopt a holistic approach to achieve long-term health and well-being improvements. The focus should shift from mere weight reduction to sustainable lifestyle changes, including dietary modifications, increased physical activity, and psychological well-being improvements. Effective intervention requires a multidisciplinary team of specialists (e.g., dietitians-nutritionists, physicians, nurses, psychologists, and physical activity experts) working collaboratively to enhance patient health and well-being.

More specifically, interventions should promote a well-balanced diet alongside regular physical activity and behavioural therapy to sustain long-term lifestyle changes. The Mediterranean diet, a well-established cardioprotective dietary model in the region, serves as the basis for this approach. It emphasises a high intake of natural plant-based fats (extra virgin olive oil and nuts), minimally processed plant-based foods (vegetables, fruits, legumes, and whole grains), limited meat consumption (especially red and processed meats), moderate fish and egg consumption, and minimal intake of ultra-processed foods high in saturated fats, trans fats, and added sugars.

Regular physical activity and exercise are crucial in obesity treatment as they enhance weight loss, reduce abdominal fat, support weight maintenance, improve well-being, and positively impact cardiovascular risk factors. Psychological therapy plays an essential role, incorporating motivational strategies, problem-solving techniques, stimulus control, and stress reduction techniques. The COM-B behaviour change model will underpin the multicomponent group education intervention, ensuring participant motivation and engagement throughout all obesity treatment phases-critical for achieving successful outcomes.

Although several scientific studies have demonstrated the effectiveness of lifestyle modification-based group interventions, their implementation in primary healthcare settings remains limited due to a shortage of trained professionals with adequate availability. This highlights the need for resource allocation to address the issue effectively. Developing and implementing specific programmes based on a collaborative and interdisciplinary care model is crucial for successfully managing obesity and its associated health consequences. Such initiatives could improve the prevalence of cardiometabolic risk factors in affected individuals.

In 2021, the Catalan primary healthcare system incorporated dietitians-nutritionists through the Programme for the Promotion of Healthy Eating and the Prevention and Management of Diseases in Primary and Community Healthcare. These professionals focus on preventing and treating nutrition-related health issues by promoting healthy and sustainable eating habits tailored to individual conditions, risks, diseases, preferences, and socio-economic and cultural circumstances, with a particular focus on vulnerable populations. Additionally, primary healthcare introduced other roles, such as emotional well-being and community health specialists and physiotherapists, to facilitate the implementation of such programmes.

This project builds on prior obesity management interventions in primary healthcare settings, incorporating insights from past participants to refine and enhance its effectiveness. It has the potential to generate robust evidence on the effectiveness of multicomponent group-based interventions for obesity and chronic disease management in adults, providing a supportive environment that fosters sustainable behaviour change for improved patient quality of life and optimal health outcomes. If the intervention proves successful, a practical guide will be developed for broader implementation across primary healthcare centres addressing adult obesity.

HYPOTHESIS Participation in the Energy2MOB group education programme for obesity management in Berguedà will lead to a reduction in body weight among individuals with overweight or obesity. Additionally, it will improve dietary habits, physical activity levels, and emotional eating behaviour, while also supporting the management of chronic diseases such as type 2 diabetes mellitus, dyslipidaemia, and hypertension.

OBJECTIVES Primary Objectives (PO)

• PO1: To assess the effectiveness of the Energy2MOB programme in achieving a 5-10% reduction in body weight among adults with overweight or obesity in the Berguedà healthcare region.
• PO2: To determine lifestyle changes related to adherence to the Mediterranean diet, regular physical activity, and improved emotional eating regulation.

Secondary Objectives (SO)

• SO1: To evaluate changes in biochemical, anthropometric, and blood pressure parameters.
• SO2: To analyse improvements in health-related quality of life, reduction in cardiovascular risk, and better management of comorbidities (hypertension, dyslipidaemia, and diabetes mellitus).
• SO3: To examine the feasibility of implementing the programme by assessing adherence, fidelity, and participant satisfaction.

Inclusion Criteria:

• Adults aged 18-65 years
• Overweight (BMI 27-30 kg/m²) or obesity (BMI 30-40 kg/m²)
• Availability to attend at least 80% (6 out of 8) of the group sessions

Exclusion Criteria:

• Significant language barriers (unable to communicate in Catalan or Spanish)
• Previous bariatric surgery
• Moderate to severe cognitive impairment
• Severe psychiatric disorders preventing participation in group sessions