Instruct: Classify Amazon reviews into positive or negative sentiment
Query: It certainly makes you think about what you eat

I have studied the theory behind Montignac's method in more detail and it seems it does not hold. Nevertheless the first independent research corroborates its effectivity in practice. The food choices promoted by Montignac favorably trigger your satiety mechanisms. People on the plan consume less calories. Probably also a psychological mechanism is effective: you realize how much baddies and how little goodies you consume.