Originally Posted by
livedarklions
The problem with CICO being stated as a simple strategy is that our data on calories both in and out are really quite poor. Calories out tends to shift down at the same level of activity as you lose weight, so there's a constant need to make adjustments to continue to lose weight.
It can be stated simply, but the devil is in the details.
If you use something like myfitnesspal they take care of reducing your basal metabolic rate as your weight goes down. Those effects are very small and not the reason people gain or fail to lose weight.