If you drink seven cans of Coke a day you’re likely going to end up gaining weight and could end up obese with all the additional health issues that brings.
If you drink seven cans of Diet Coke per day you’re not going to end up obese (through that method anyway).
What seems to be missing in this HN debate is that sugar itself (yes the natural substance) is not good for us either! Aspartame may be “bad” (debatable) but sugar is bad but in different ways.