Why raw vegetables help you lose weight.

It is unadulterated fibre which is the matrix of raw vegetable and it is that which makes your intestines work to break it down.
Apart from exercising the muscle layers of which the bowel is made, from tongue to tail, it uses a great deal of energy doing this. It means it will keep you lean.
Of course the antithesis of this is cooked vegetable which is, as I have previously mentioned, is identical to rotting and from a health point of view probably worse. This is because the heat of cooking destroys nutrients much more effectively than aerobic oxidation at room temperatures.
I mention, somewhere, thinking about a liquidizer or blender making a selection of raw vegetables such as you would make for a meal to end up like the soft putty you excrete. This really does take some energy. These machines vary from 350  to 1250 watts with a mean somewhere in the region of 680. This is nigh on one horsepower and kept on for five minutes is five  horsepower. Of course you're deploying this energy over 5 to 8  hours.
Never the less this is real energy you are deploying in your gut and it uses up the calories you so want to lose. Remember your bowels were designed for roughage and not refined food, be it cooked vegetables, or other refined carbohydrate,  so all you are doing is what nature intended.