Lust is defined as the obvious falling for another person in a carnal way. The lust does not show only emotional, but also physical weakness, which reduces the loyality for the own being. To fall for lust is considered a lack of self control.
Gluttony is considered as the mindless waste of food, which is necessary to survive. The critical point for this sin is wasting food which another person could need to survive, or which could be used in times of need.