The minute you cook any food it loses its value; Ever boil green vegetables and see the nice green water after your done? Thats your vitamins and minerals you boiled out. Hence why I love my steak rare and try and cook everything to just about done and stop. While your food is resting it is still cooking until it is not hot anymore.

Raw veggies are ideal - but can taste nasty and not all can even be eaten raw. Boiling is likely worse than saute or steaming because the nutrients are being pulled out by the water and your discarding the water.

Organic spinach in the blender, roasted or fried eggplant, raw carrots, lightly steamed broccoli, satued green beans with copious amounts of garlic and grass fed butter.

Pumpkin soup is or mashed squash are good too, but more of a B list, not exactly on the weekly rotation.

Yes, I have heard up to %40 loss. Baking, pan sear, and grilling are g2g.

I believe there is also a sticky stating some advice on this too.