Squats-a-lot! Welcome back.
I eat tons of bacon and my body fat fluctuates between 9-11%. I do not have any sort of obsessive diet at all, I drink alcohol and eat pizza at least once a week.
It’s pretty easy if you’re supplementing protein. Just eat protein rich meals when you can and supplement what you don’t get with whey protein.
Thinking in “calories in, calories out” is a flawed and incomplete way to look at it because different kinds of calories have different hormonal effects, which is the important part, not the actual number of calories. After reading Tim Ferriss’ experiments into this where he ate 7 times his resting metabolic rate and lost weight, I tried something similar and didn’t gain weight either. Digestion is an important factor too since it’s what hits your bloodstream that counts, not what goes in your mouth. There are a lot of ways to burn calories aside from exercising.
I roughly calculate protein but don’t bother counting calories. Then again, I’m pretty comfortable at 205 lbs with 10% body fat, spending a total of 60 minutes in the gym per week.