Now that we've covered the four pillars of health and fitness - diet, sleep, stress, movement - let's discuss the connections between them so that we have a more integrated understanding. These four categories are not independent of each other. The value of thinking in terms of these categories is that it gives us a framework to assess our behaviors as they relate to our health, however it's important to realize that activity in one pillar usually affects the other pillars.
For example, if our sleep quality goes down we will experience increased appetite (for junk), lowered energy levels for exercise, less recovery, and a lowered resilience to stress. You can do a mind experiment to see how this plays out. [Short on sleep for a couple of days] I want doughnuts for breakfast! ... Let's skip the gym today - I'm just not up for it... Hey, pal, you just cut me off! ... Nobody does that to me! [BEEEEEEP].
We can play the same game with any of the pillars. Lower the quality of one, and watch the others get impacted negatively. Think of your health as a ship and the four pillars as motors. In order to navigate that ship where we want, we need all four motors running efficiently AND pointed in the same direction. As a personal trainer, I've given a lot of thought as to whether it's better to not overload a client - limiting the focus to only one pillar (say exercise). However, I think this approach would be a disservice. Although it may involve more changes at first, addressing issues in all four pillars ultimately results in making better progress towards their goals... and progress is hugely motivating. Also, with a holistic approach none of the changes are extreme. It's always about implementing behaviors that are practical and sustainable. Slow and steady wins the race.