I dont think it's a leap too far to suggest that spending less on any line item is a step towards a balanced budget ie eliminating the deficit. And once a deficit is eliminated we can begin to work on the debt. What proof is required when it's very simple maths.

Here's a reference if you need one - "“Annual income twenty pounds, annual expenditure nineteen nineteen and six , result happiness. Annual income twenty pounds, annual expenditure twenty pounds ought and six, result misery”

https://www.goodreads.com/quotes/90487-annual-income-twenty-...