The most important part of treating eating disorders, aside from weight gain for severely anorexic patients, is Multiple choice cooking techniques. social involvement. psychotherapy and behavis.

To determine the most important part of treating eating disorders, especially for severely anorexic patients, we can analyze the options provided: 1. **Cooking techniques**: While learning cooking techniques can be beneficial for some patients, it is not the primary focus of treatment for severe anorexia. 2. **Social involvement**: Social support can play a role in recovery, but it is not the most critical aspect of treatment for severe cases. 3. **Psychotherapy and behavioral therapy**: This is often considered the cornerstone of treatment for eating disorders. Psychotherapy helps address the underlying psychological issues, and behavioral therapy can assist in changing harmful eating behaviors. Given this analysis, the most important part of treating eating disorders, particularly for severely anorexic patients, is **psychotherapy and behavioral therapy**.