This is exactly correct. No matter what diet you do, it is calories in calories out. The advantage with Keto is that your body learns to use the access fat as fuel but if the calories surpass your maintenance caloric intake, the lbs. start to come back and yes I've done them all.
Eating small clean meals 6 times a day and staying within a caloric deficit also works great but it's hard to eat every 2 or 3 hours with a busy work schedule.
The best two things one can do is eliminate sugars and alcohol from your diet and stay in a caloric deficit 5 days a week.
When I lost my weight last year, I reduced sugar. That was my start. I was not interested in losing weight fast, I wanted to lose it for good and in a way that would work for me in the long run. I started with no pop and reducing the amount of sugar in my coffee. I went from two teaspoons to one for all last year. This year I cut that in half now as well. My goal is to get to no sugar.
I figured this was better for me personally overall. No point in reducing caloric intake if you will just go back later and will still be eating the same bad food.
I also did small meal sizes. Portion control was big. Now I can maintain a weight with the regular eating I do now. So this year, I will work out to help build my strength in the areas I want and I know that will work in reducing weight this year.
My goal was a better me in long run so if it takes me longer, cool.
But sugar was clearly my main killer. Losing the weight I did from simply removing sugar showed me that.