Yes, there's a role for the physical therapist (PT) in helping patients understand how nutrition affects function, but there are nuances to be considered and no shortage of factors that could affect just how to fulfill that role. Fortunately, there's now an APTA webpage that helps PTs navigate the issues.
New to the APTA website: "Nutrition and Physical Therapy," a webpage with a collection of resources that delivers context for APTA's position that it's the role of PTs to "screen for and provide information on diet and nutritional issues to patients, clients, and the community"—within the bounds of the PT's scope of practice. That means, among other things, that PTs wishing to provide information on nutrition need to be certain that they're doing so in ways that are consistent with state licensing laws for both physical therapy and nutrition services, and assess whether this ability is within their personal scope of practice.
The webpage provides factors to consider related to the PT's role in nutrition and diet, including additional certifications that may be required, use of the designation "nutritionist," and when to refer a patient or client to a specialist for nutritional education. Other resources on the page include links to dietary recommendations, a registered dietician nutritionist lookup, and information on how to pursue additional certifications.