Increased energy level compared to low-fat diets. If you keep your fat intake somewhat balanced, i.e. not exclusively saturated fats, you should have no problem. Your actual mileage may vary - test your Cholesterol level before you start. Keep sodium intake reasonable, some meat products can be pretty high. I eat salad with lunch and dinner, and never had any problem.
First week can be rough - stick with it.
During the weekend, be careful with foods with high glycemic index - they can wreak havoc on your insulin level, and switch you into fat storage mode more quickly. Try to get as much natural fiber as possible from salad or vegetables, while staying within the 30g carb target. Supplements One of the nice things about this diet is that you won't have to spend much money on supplements. The book also recommends Omega 3 fatty acids, e.g. from fish oil capsules. In general, it is a good idea to have some variety on the types of oils you eat.