For me, this sounds a bit tautological. Of course the opposite of procrastination is action.
It’s similar to saying, “If you want to lose weight, just eat less.” It’s certainly true on a meta level, but very difficult for some people to implement.
If you want to lose weight but don’t feel motivated, it might be because you associate getting started with a strict workout routine and highly restrictive dieting. But taking smaller steps in the right direction can spark motivation. From my own experience, I know I naturally start eating healthier as soon as I get back into running.
That said, in practice it may be reasonable advice on average, but there's also a problem where it's not very practical to eat the "same" calories as someone else, unless they are together with you all the time.