Any portion and calorie controlled meals will help you lose weight, however, you have to make sure that you are getting enough nutrition through fresh fruit and vegetables along side them. At the end of the day they are still processed meals, so the key would be to eventually learn how to mimic them but with fresh ingredients. But if they work for you then by all means keep going. One of these meals a day, especially if you would be eating other processed foods or take away instead, are a great way to watch your calorie intake.
I used to work for Jenny Craig, which also has these type of meals, and the clients had very good results with it.