Are my two friends nutritionally nuts?

I have two male friends that are both trying to control their weight. One weighs about 415 (down from 598!) is a Non-Op, exercises daily for at least an hour (walking, exercise bike) and eats a low calorie diet, but "doesn't like meat so much" and only consumes 30g of protein a day. Is this safe? What are the ramifications of not eating more protein? I have another friend who had an RNY in the Spring, runs several miles a day, and does a lot of martial arts-- and eats 500 calories a day. He's in his mid 200s (down from upper 300s) but has been on a plateau for many weeks now. Isn't that a ridiculously low calorie count for a very active person? Is it possible that his body is holding onto his fat storage for dear life?

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