Improving Mental Health and Wellness in Schools Act This bill incorporates mental health promotion and education into guidelines for school wellness policies that are used by local educational agencies participating in school meal programs. Specifically, the Department of Agriculture (USDA) must issue further regulations for local educational agencies to (1) incorporate goals for mental health promotion and education, and (2) include reducing eating disorders as part of the nutrition guidelines for foods available on school campuses. The bill also requires that local educational agencies establish multidisciplinary teams of school personnel to lead the development, periodic review, and updating of local school wellness policies. Further, the bill requires the involvement of registered dietitians and school-based mental health services providers (in addition to those already required to be involved) in the periodic review and updating of the local policy. USDA must also provide technical assistance to promote mental health, encourage mental health assessments, and establish resilient school environments.