Most people don't eat enough protein or focus on it.
Look at certain foods, they make a big deal when is has
8g of protein in it, like that is amazing.
Most people eat way too many carbs and food that is also higher in fat, both are energy sources.
* I track my macros/food and keep my cals in check: protein at or over 200g, carbs 200-500g and fat 50-60g.
I can eat a good amount of food daily and can still lose body fat: if I keep my protein high fat low and carbs high.
* I can also lose body fat if I keep my protein high and fat high to moderate, but carbs low.
I track my step count: 10k a day or more daily and lift weights a few times a week.
I am 44 now and in great shape and this makes staying in shape relatively easy.
I found things I can put in rotation, eat and enjoy on a daily basis.
I get

when I am just eating whatever, mostly high fat/carb foods and not focusing on protein.
Backstory, I used to eat cinnabon a lot on certain weekends, 2-4 a weekend going to the mall or whatever.
Once I started tracking, I realized they were 800 cals + each. (can not tell you the last time I have had one since)
I knew they weren't good nutritionally, but I did not know at the time what my intake was just on cinnabon.
1600-3200 cals just on Cinnabon, not including all the other food/shyt I used to eat on weekends too.
This is how you mess up a "clean week of eating" M-F with (I eat whatever on weekends).
Tons of people do the same sort of things, but with other foods, sodas, star bucks and alcohol, etc on a daily basis.
It adds up quick, especially when you aren't aware of what you are ingesting or don't know how to read food labels/serving sizes.