Used 2 and a half packs on ascent of Manaslu - 8163m in Nepal. I was afraid to use more as I did not know how my body will react to just eating sugar for more than 10h. Not sure they helped much but I did not get sick. Did not want to eat more as I was afraid I may get sick. At least I know few packs is safe for me per day. Even in the death zone. You need to know that over 7000m almost all digestion stops and over 8000m you cannot eat anything. Here basic sugars are important as they do not require digestion or such needs are almost zero.