This dietary plan is Bad Psychology because it fails to address the problem of your fat body image. Unless you follow the ideas suggested here, any weight loss program you start such as the cabbage soup plan is likely doomed from the start.
This cabbage soup eating is Bad Psychology because it will almost surely result in ultimate failure with subsequent loss of wellbeing. This eating effort surely will ultimately fail because it does not require some regular mild aerobic exercise so that your metabolism can change.
This cabbage soup dietary program is Bad Nutrition. No one should try this rigidly for more than a few days at a time. A better choice would be just to add cabbage soup/ grapefruit/ other-healthier-food to your current eating habits. Doing things by ADDING will help you in Changing Food Preferences.
Please read the Brainwashing pages below which DO have the ingredients for success.