The purpose of the study is to explore and deepen the understanding of the dietitian's role and work related to individually tailored nutritional treatment in cancer care. The research questions focus on behavior change strategies, goal setting, the possibility of using calf circumference to assess changes in muscle mass, and mapping energy and protein intake, nutritional symptoms, and food-related quality of life during nutritional treatment for cancer patients.

In the first part of the project, audio recordings of conversations between dietitians and patients with cancer will be conducted to investigate the dietitian's work with behavior change strategies and goal setting. Data analysis will be performed using two different methods: content analysis and thematic analysis. The research subjects include both dietitians and cancer patients who engage in conversations.

The second part of the project will include 100 patients with cancer at risk for or with malnutrition. Data collection will involve measurements of weight, height, calf circumference, muscle mass, energy and protein intake, nutritional symptoms, and food-related quality of life.

Inclusion Criteria:

Inclusion criteria for the first part of the project involve encountering dietitians treating patients with cancer who have malnutrition or are at risk of malnutrition. For these patients, the inclusion criteria are as follows:

• aged ≥18 years with a diagnosed cancer
• ongoing nutrition therapy by a dietitian
• malnutrition or risk of malnutrition according to the hospitals criteria where at least one of the following criteria must be met: low BMI, involuntary weight loss, and/or eating difficulties. Patients can also be included if they are referred to a dietitian based on treatment guidelines due to a high risk of malnutrition associated with the cancer diagnosis or its medical therapy.

For the second part of the project, the inclusion criteria are:

• aged ≥18 years with a diagnosed cancer
• undergoing or planned treatment, including surgical, oncological, or a combination of these
• have been referred to a dietitian but have not yet had their initial contact with the dietitian, and
• malnutrition or risk of malnutrition according to the hospital's criteria, where at least one of the following criteria must be met: low BMI, involuntary weight loss, and/or eating difficulties. Patients can also be included if they are referred to a dietitian based on treatment guidelines due to a high risk of malnutrition associated with the cancer diagnosis or its medical therapy.

Exclusion Criteria:

For the first part of the project, the exclusion criteria regarding patients are:

• known dementia or impaired cognitive function, and
• not proficient in spoken and written Swedish.

For the second part of the project, the exclusion criteria are:

• known dementia or impaired cognitive function,
• ongoing nutrition therapy by a dietitian at inclusion, and
• not proficient in spoken and written Swedish.

In the first part of the project (non-probability sampling method), research participants are registrered dietitians in Sweden and patients with cancer who have malnutrition or are at risk of malnutrition. The participants are recruited systematically through a strategic or purposive selection within the hospital setting.

For the second part of the project (probability sampling method), research participants are patients aged ≥18 years with a diagnosed cancer who are receiving or scheduled to receive treatment, including surgical, oncological, or a combination of these, at Uppsala University Hospital in Uppsala. The patients should have been referred to a dietitian but have not yet had their initial contact with the dietitian at the time of inclusion.