Yeah, nuts! For the fellow eating 30 g of protein a day - are you sure those calculations are correct?  I am always suspicious that the less obvious sources of protein might be overlooked - those in bread, vegetables, and legumes.  If it is an accurate accounting then I would also be concerned. Protein malnutrition is a real, and problematic thing.  If he is exercising vigorously then the body will work hard to maintain skeletal muscle and the diaphragm, but the protein has to come from somewhere.  His body is probably not maintaining its immune function and other systems to keep up with the demand of his exercise and poor diet.  The end result is, when he gets sick, he will get really sick.  If he has an injury, he will have a hard & long time healing.  The body is amazingly adaptable and overt signs of protein malnutrition may not be evident even with routine lab work.  One of the clinical markers of protein malnutrition is a normal albumin level. If he doesn't like meat so much, there are a zillion alternatives out there.  A large part of the world eats minimal animal protein, instead they eat beans/legumes, soy, and dairy foods.  It is very possible to eat adequate protein without meat, it simply requires a little more attention to detail. On to friend number two.  500 calories a day is low, but not unusual for recent RNY patients.  If his 500 calories a day comes mostly from protein (I would ballpark that his protein needs are around 100 g per day, multiply that by 4 kcals/g, and that makes 400 kcals of his 500).  His activity will help to speed up his weight loss, and yes, the body will still reduce its resting energy expenditure to compensate for the lower calorie intake.  He is actually doing the right thing - while eating a very low calorie diet, maintaining his activity to force the body to burn the stored fat and not reduce metabolism too much.  Very low calorie diets and inactivity are a bad combination - the body will dial down its metabolism and weight loss will be very slow.  As far as his plateau, sometimes it is the body seeking a balance.  If he is not retaining a lot of fluid (indicating an alteration in protein balance, electrolyte disturbance, or other medical problem) he is going to have to wait it out.  If he is eating a lot of carbs, he may want to up his protein intake. Our bodies will hold on the the fat, to a degree.  Women's fat cells are particularly good at hanging around - especially those on our hips & butt.  Men usually have a higher amount of abdominal fat and that type of fat is more transient - this is why abdominal fat is associated with higher cardiac risks.   It goes back to our biology (and sociology too) - men were designed to go out, slay the beast, and bring it back to the tribe to eat. Men burn their fat in quick spurts and they will perish long before the famale of the species under adverse cir****tances. Women were designed to carry a baby to term while not eating and dragging ourselves across the Sahara - our fat is stubborn because it is a sustained source of energy.  The body will use the fat as it needs to for energy, but it will reduce its needs first (reduced metabolism). So slap those two around a little!  And let me know if I gave you all the ammo you need to let them have it! Danielle Halewijn RD eNutritioncare.com

The amount of calories and protein you need are based first upon your height and weight, second on your activity level, and third on your medical history. (this information may be more private than you want to share here) Another good place to start is where you are now.  Calculate what your current calorie & protein levels are (keep a daily diary and punch it in to one of the on-line trackers).  Look at an average over 3-5 days, since people don't eat exactly the same thing every day.  Take your current intake and drop it by 3-500 calories per day.  Try to maintain the protein level the same if you can.  Try substituting very lean meats, reduce the amount of oil or butter you use, cut out unnecesary snacks, etc. And my favorite - don't change your eating at all just increase the intensity of your workouts.  Walk a little faster, go 10 minutes longer, etc. Danielle Halewijn RD eNutritioncare.com