Even if those are the fundamentals, it's still worth looking at the thought patterns that some people get trapped in which prevent them doing what is considered "easy" by others, and especially understanding if those traps are subject to certain tricks or shortcuts.
For example, I put on about 20lbs early in the pandemic just from being around the house and being able to snack all the time, plus having ice cream a lot in the evenings before bed (I don't think I was particularly "stress eating", but maybe more like... boredom eating?). And yes, if a dietician or trainer had had me keep a food log, this would have clearly shown up and it would have been obvious what needed to change.
What actually worked for me, though, was not just cutting out the snacking but also shifting my mindset back to a place where I'm okay with being slightly hungry some of the time. Like, it's okay to feel peckish in the afternoon— it's not a problem that needs to be solved by having a snack, it's just a sign that I'm going to be good and hungry come dinner time. Same in the evening: I don't need to go to bed stuffed, I can just make sure to eat a solid dinner, and then plan on eating well at breakfast in the morning. That plus some protein shakes and getting more cardio (swimming, cycling), and I've been steadily shedding about a pound a week; I'm now below my pre-pandemic weight.