You say you have 40 pounds you want to lose by swimsuit season? Please, please, please be very careful. You might be able to achieve half that amount (which is still fantastic!) by the beginning of summer...IF you eat in a way that's good for your body. I'm currently seeing a nutritionist (who has me on a close approximation of ER4YT--modified to include some more recent research by other naturopaths) about my diet, primarily to control the dreaded allergy/asthma/sinus triad, but also to lose a little weight.
If you're on a good, healthy eating plan and getting lots of exercise, you should be able to lose 1 1/2 to 2 pounds per week. If you lose more than that, you're doing several things that are actually harmful to your body: you're most likely burning muscle mass, you're putting your metabolic rate into panic mode, and you're putting extreme stress on your liver, pancreas and adrenal system. Not only is this bad for your body, but even if you DO lose weight more rapidly than that, your body will get even with you for starving it by rapidly gaining the weight BACK. Those of us who've yo-yo'd for years should know this well (even if we hate to admit it!).
You'll probably find that you a little weight without even TRYING by modifying your eating habits to better suit your blood type; if you have a little patience, you'll find that this may be the easiest way you've ever lost weight, and if you maintain the ER4YT habits, you'll keep it off and feel better than you have in years. Because of the extreme diets I've been on in the past, I almost feel as if I'm eating too MUCH now, but the weight is steadily dropping off (almost 18 pounds to date) with very little effort. I eat three good meals a day, with a good, protein-based snack between meals twice a day--AND I use olive oil to cook with and as a dressing on my salads without giving it a second thought. How great is that!!!
I identify with you totally--summer approaches, and the pressure is on to be nice and trim in time to hit the beach. BUT--there are no miracles, with the possible exception of the one you do for your body by treating it right (as this nutrition plan certainly does). I promise you, your body will reward you if you feed it well, exercise and DON'T try to starve yourself!!
Eating as many HBs as possible will help you, as will drinking lots of water, and of course lots of exercise (to keep your metabolism up). Also, lifting weights will help boost your metabolic rate and improve bone density at the same time. I'd been "brainwashed" into thinking that yogurt and other supposedly "really, really healthy!" foods would help me lose weight, but as a type O, I now know that's not the case.
Take a deep breath (and did I mention that deep breathing exercises are also good for the metabolic rate), don't get impatient with yourself, and ENJOY your new "diet."
Hang in there--it'll pay off, and you'll feel great!
P.S.--I cannot recommend strongly enough that you see a nutritionist (and one who follows ER4YT); the support and guidance are invaluable, and she may kill a few myths for you. I thought I needed to weigh a teeny 120 pounds to be in optimum shape, but based on the body mass testing that she did, I now know that I'll be healthier (and still around a size 8) if I'm closer to 140 pounds! I was shocked, because that number always sounded SO FAT to me. I was SO wrong. One of your biggest hurdles will be to clear those Vogue-magazine induced ideas that if you're a certain height, you should weigh a certain number of pounds. That is NOT necessarily the case, and you're putting unnecessary emotional stress on yourself if you obsess about it. It'll be good for your overall health, and even better for your mental health if you see a practitioner who can give you some guidance on this.