Cooking food destroys enzymes, vitamins and other nutrients. Many of the minerals are leached out into the cooking water, then thrown away. So cooking should be kept to a minimum. Eat as much raw food as you can. Make sure at least a third of your diet is raw. More if possible. This is easier in summer than winter, so make the effort in winter, too.
A great book or dvd on wonderful recipes using raw food is Living on Live Food by Alissa Cohen, You can purchase them by clicking on the links below:
The book is available at Living on Live Food book
The dvd is available at Living on Live Food dvd
Whilst a simple, peasant diet is more conducive to a long, healthy, energetic life and to keeping our weight to an optimum, few people will be able to keep to it rigourously. Give your self realistic targets. Maybe have a small treat every day of something ‘unhealthy’. Maybe have a 'bad' meal once a week. Then you can work on that, gradually increasing the healthier food over time.