Yes, exactly! Zero cheating and accurate measurements seem to be paramount. I'm glad for some of the others posters who could take a more lax approach and only eyeball stuff or vaguely count macro, but that didn't work for me at all.
It is indeed true that calorific deficit and accurate measurements is the best way to predictable weight loss.
But can you eat chicken and brocoli for the rest of your life? Can you do zero cheating and accurate measurements for ever? Is losing 15 kgrs in 3 months healthy? It is very easy to take the weight back and then some. There is a reason we have the term yo-yo dieting. :(
Food is sustainance, but also is enjoyment. Following a more lax approach where you ease into a better diet and keep enjoying food is a more sustainable long-term approach. Lose 15kgrs in one year instead of 3 months and magical things will happen. After 3 months of hard dieting you will probably reach for a chocolate during a crave. After 12 months of moderate dieting, you will reach for an apple and you will enjoy it as much as a chocolate. Reprogramming ourselves takes time.
Is losing 15 kgrs in 3 months healthy? It's healthier than staying fat..