What is the grammar behind this type of sentence structure?

Taylor described this danger to the Huffington Post; "I see clients for whom food has become problematic, and they struggle to go out and
not have food be the key element of all social interaction: what they
eat, when they ate, when they are going to eat again."

I know what Taylor means is that if some of her clients don’t see food as the key element, they feel reluctant to go out. How to explain this usage of two "negatives?"