BUY THIS REFERENCE GUIDE
This book is a nutrional plan approach based on individualized blood types. I won't get into the science behind it as the book itself does a nice job of explaining it in the first chapter before laying-out what makes each blood type gain weight. I studied the science of this while in university which forever changed the way I ate. If you're lazy, don't have time to exercise, but want to get back down to your natural weight, this is the way to go.
I put my (now) husband on this, and he lost 20lbs by simply not eating something his body cannot break down. In his case, it was red meat as he has Type A blood. For me, having Type O blood, I couldn't break down wheat, but red meat was fabulous for me. We both ended up looking AMAZING for our wedding without hitting a gym (didn't have the time!!). People always ask me how I look so fit and stay thing, and this is the answer.
BUY THIS BOOK!