The aging population faces two conditions that threaten healthy aging: high fat mass (obesity) and low muscle mass and function (sarcopenia). The combination of both –referred to as sarcopenic obesity– synergistically increases the risk of adverse health outcomes. The two conditions often co-occur as they reinforce each other and share common etiologies, mainly poor nutrition and inactivity.

Although all aging people are at risk of gaining weight and losing muscle mass, there is an even higher risk of becoming overweight and sarcopenic during the transition from working life to retirement, due to changes in poor nutritional intakes and lower physical activity levels. However, because of these rapid changes, retirement also offers a great window of opportunity to improve lifestyle, as older adults already need to restructure their daily activities. Furthermore, adopting a healthy lifestyle around the age of retirement offers sufficient time to prevent obesity, sarcopenia, sarcopenic obesity and provides long-term benefits, including healthy ageing and prevention/delay of dependence in later life.

To stimulate weight loss/prevent weight gain while preserving muscle mass, it is critical that both physical activity and adequate nutrition be addressed. It is key to change behavior in a sustainable manner, providing scientifically proven, personalized, and acceptable principles that can be integrated in daily life. Health technologies (e.g. applications, wearables) can provide promising tools for delivering personalized and appealing lifestyle interventions to a large group of people while keeping health care costs low. At this moment, there is a lack of effective, sustainable interventions that focus on retirement as an important turning point to promote both nutrition and physical activity behavior.

We aim to provide essential insights required to develop innovative strategies for preventing obesity, sarcopenia and sarcopenic obesity taking into account sociodemographic and health-related characteristics. Based on these strategies and new knowledge, we will design the personalized, cross-country SO-NUTS application that helps empowering people around the phase of/after retirement to lose weight while preserving muscle mass and function. We will test feasibility and effectiveness in a pilot study and secure implementation and dissemination with the help of an extensive network reaching through Europe and beyond.