There are loads of benifits!
A particular one you might want to mention is the role of fibers in weight-loss.
Fibers will fill you up, without contributing to your calorie intake. Therefor, a meal with lots of fibers will make you feel satiety, even though the energy intake is quite low.
Lentils are great for a vegetarian weight-loss diet. Green lentils contain as much as 30% fiber. Cook them, and put them in a blender with spinach, vegan "milk", tomatoes and spices. It will make a great pastasauce. (just remember to use wholegrain pasta).