Comment by nradov
3 years ago
The most likely possibility is that you were simply underestimating your calorie consumption. A lot of people forget to count the creamer in their coffee, the candies from the office break room, the little tastes while cooking dinner. Unless you have a severe metabolic disorder your body will only burn lean muscle mass as a last resort when you have exhausted glycogen stores and can't sustain the energy demand from fat alone. Some weight training is always a good idea, though.
I explicitly overshot the goal by more than 500 calories. Yes, there are always mistakes in estimation, but that isn't what was happening. Remember, I've done this before successfully.
A catabolic state induced by caloric deficit will absolutely consume lean muscle mass regardless of the availability of fat reserves. Muscle stimulus (via weight training, for example) and sufficient dietary protein can prevent this. But if you're just dieting without specifically controlling this, you will lose muscle along with the fat.