Can you gain weight from the artificial sweeteners?

No clear answer: Theoretically no. Most artificial sweeteners are labeled non-caloric, because there is no calorie absorption and induced weight gain, but more and more studies that look at the long term effects of artificial sweeteners have shown correlations between weight gain and the use of sugar substitutes. Without long term and more comprehensive studies to support that correlation the answer is not clear.

Yes, but: Not due to the artificial sweetener itself. So if eat foods that have them, but have , say, more than 60 calories per serving, and eat many servings, you will gain weight but if have them in foods that only have a few calories per serving- diet sodas, diet tea, diet jello, unlikely to gain weight.