Agree with the water, though - I've always got a big water bottle next to my desk.
I lived my whole life with barely an understanding of the macronutrients, wrapped in popular wisdom: eat enough fiber, protein is good for you, be careful with carbs, sugar is bad (but you can't avoid it).
I also casually dabbled with some fashion diets, experimented with apps for counting calories, and grew up with plenty of wrong and harmful advice (fruit juice is healthy, honey & cereal as a healthy breakfast, etc). Nothing really stuck.
I never understood why sugar is bad, or what's the difference between fiber and carbs (aren't they both plants?), what happens in your body when you eat carbs, or what the heck are calories anyway?
It was only when I read more about how your body processes food and the impact on your glucose levels that things started to click for me. I also got a CGM, and started seeing the direct correlation of the spikes and crashes with mood, cravings, motivation, post-lunch slump, headaches, energy levels.
It has also completely changed my relationship with food. I started eating more, lost weight, and my glucose levels are significantly lower (and, more importantly, I know exactly how to control it). Also have a bit more energy, less cravings, no post-lunch slump.
There's plenty of resources out there, but the three that helped me were [1][2][3], and a Dexcom CGM (but that's totally optional).
[1] https://www.amazon.com/Glucose-Revolution-Life-Changing-Powe...
[2] https://www.amazon.com/Glucose-Goddess-Method-Cutting-Cravin...
It's just that people refuse to engage with a simple diet. All you have to do is start to cook for yourself and it's done, your diet is solved by the required meats, vegetables and carbs you get in a basic home cooked meal two times a day. Even if it's reheated.