I'd say skip this one if you are trying to lose weight. The Special K or Weight Watchers meal replacement shakes are higher in protein and fiber, less sugar, and would be a better option. Pair them with a little bit of fruit, and you'll be good until lunch time.
If you're trying to lose weight, the best thing to do would be to not drink chemical-laden crap like this, and instead focus on eating healthy, organic veggies and other real food, and exercise regularly.
This is NOT the product you want to use id trying to lose weight, only if you are looking for a quick and delicious meal replacement. This product is full of sugar and it tastes best with whole milk....both of which are definitely not diet friendly. A FULL glass of water every morning will TRULY help you dieting. :)
I wouldn't use this to lose weight, you would think it would because it does fill you up but it also depends what kind of milk you mix into it (1%, 2% etc). However it is a good aid to help you with your weight because of all the useful vitamins that are necessary to stay healthy. The only aid in this product that would help your weight is the Protein, so look for things with high protein content to help slim down.