I've been on the slim fast diet for a few weeks now. I've lost from 145 to 138.4. The first couple weeks of it I would only have 1 shake a day. The past week I have been doing a shake for breakfast and a shake for lunch and a normal dinner trying to meet a 1200 calorie diet. Ive pushed myself these past 2 days on burning calories and have burned alot, but today I woke up feeling really tired. No energy at all. I'm wondering if anyone else has experiences this with this diet? Or if maybe I just didn't have enough calorie intake after burning so many? Is the slim fast diet worth doing and im getting all the nutrients I need or does it have bad stuff I don't need in it? I'm happy at losing the weight but I don't want to keep having this kind of energy level drop.