I used the South Beach Diet about 3 years ago and lost 15 lbs in about 3 weeks — I’m 6’1 and went from 190 to a manageable 173. “Manageable” means eating relatively healthy with an occasionally treat. I do a cardio + weight workout 3 times a week and have a reasonably active lifestyle. If I tried (i.e., skipped the beer and goodies) I could maintain 170.
The basics of this diet are similar to what several people have written: reduce sugar, fats, and carbohydrates, increase protein via lean meats like turkey, skinless chicken, and Canadian bacon. There is a surprising amount of sugar in fruits and juices so this diet trains you to understand moderation. For example, orange juice is good for your health but a 12oz. glass of orange juice represents about 3-4 oranges and quite a bit of sugar. Yes, you still need salt in your diet but there is a surprising amount of salt in many prepackaged foods. I salt food moderately as I cook it but never add salt at the table.
Bread and pasta metabolize as sugar so these are reduced substantially as are rice and potatoes.
The diet defines 3 stages and the first stage is strict (no sugar, no bread, pasta, rice, beer, etc.) Think tuna fish wraps, celery snacks (no carrots because they contain sugars), lots of water, Total cereal, and 1% milk. Coffee is not restricted but a reduction is recommended since it stimulates appetite.
Phase 2 lets you have bread and after about 2 weeks without that first piece of toast was heaven.
Anyway, it is a logical diet that is not really earth shattering but lays out a plan that is easy to follow. The book has many good recipes and ideas in it.