What you just said has a TON of merit.
Everything in moderation. Eating desserts or things with low nutritional value are fine, just don't eat them everyday or more than twice a week.
Processed foods are the real culprit of malnutrition. Things chalked full of preservatives, sodium, or simple sugars are not good for the body. Period.
Common sense goes a long way with diet. So is understanding your health and eating accordingly. For example, if you have high cholesterol, eat more fish, chicken, and turkey, and avoid a lot of red meat, especially with high fat content.
Meal prepping helps me stay on target. It sounds tedious at first, but all you need is an hour or two one night a week to prep meals for the next week.
I'm lucky in that I've always been skinny, healthy, and had the metabolism of a field mouse (not to mention I'm still young), so I can get away with more cheat meals than the average bloke. However, now that I'm 31, I notice I don't rebound as quickly after eating a crappy meal as I did even just a few years ago.
And what I mean by that is even with a strict workout routine, my workout performance drops considerably the next day if I have pizza for dinner the evening before. I'm also just less motivated to do stuff. But that brings me to another point: the more you pay attention to what you eat, what you drink, or how much water you're drinking, the more you understand your body and the better you're able to accurately diagnose and respond to what your body is telling you it needs (e.g., hunger pangs vs. thirst).
The problem is, what you and I have said is not what most people want to hear; it sounds like too much work. Well, it is work. But you spend a lot of time doing other stuff, why not spend a little more time making good food decisions that ultimately make you physically and mentally healthier, giving you more quality time to do fun things?
