It's more likely to happen if your deficit below TDEE is greater than 500 Calories. If you're 500 below BMR, you're almost definitionally losing weight at an un

It's more likely to happen if your deficit below TDEE is greater than 500 Calories. If you're 500 below BMR, you're almost definitionally losing weight at an unsustainably unhealthy rate, like much greater than 1% of your bodyweight lost per week.