Confused about calories, resting metabolic rate

Hi everyone,

I'm hoping there are some people here who have experience who can give me some insight or advice based on either your personal or professional experience with weight loss and fitness.

The Backstory
Have lost 85lbs since January 2010 with the help of lap-band surgery. For the majority of this time I have eaten 1500-1800 calories a day, more on some days certainly, and exercised a good deal. Obviously what I've done has worked up to this point.  Eating only lean protein and vegetables 85% of the time has also been key. I've avoiding grains, sugar, and most carbs other than beans and nuts.

Recently, my band has (finally!) achieved the level of adjustment that I/my doctor seek which means I am satisfied on 1200-1300 calories a day as long as I really do only eat lean protein and vegetables. I can easily eat more if I want to by choosing foods that don't work with the band like ice cream or cookies but the key thing to remember is that if I eat what I'm supposed to, I do not want to and am physically incapable of having more than about 1300 calories a day. What I mean by that is I will end up throwing up if I try to eat more.

I participated in a high tech body composition thing yesterday, similar to a dunk tank but it's a new method using air displacement instead of water displacement and is supposedly just as accurate. I was told my Resting Metabolic rate is 1518 calories per day and that to lose weight I should not be eating less than that.  I imagine the theory is that if you eat less than your RMR your metabolism will slow down or you will break down muscle to get energy? (I dunno? you tell me?)

I still have 70 lbs of fat on my body so I'd like to ideally lose 35 lbs of fat which would leave me with 120 lbs lean body mass and 35 lbs of fat. I know this is not a professional athlete type goal but it's what I want, so please no comments telling me that I should be aiming for something different than what I am. These are the facts, which I'm giving so that you may, if you wish, try to give some advice.

Hopefully the conundrum is now obvious:
If my RMR is 1518 and, accordingly, me just going about my daily life burns about 2200, and on top of that I'm doing exercise like jogging, weight lifting, horseback riding, and rock climbing around 5 times a week (cumulatively) AND I'm eating 1300 calories a day, then why is fat not just falling off of me? I've been at the same weight for the past few weeks, a bit of a plateau I guess, but it ****** me off because scientifically it just doesn't make sense.

Furthermore, I want to understand this "don't eat less than your RMR" thing because interestingly, when I told the guy who was conducting the body composition test that I'd had a lap band, he said "oh, well then this may not apply to you."  So... I don't get it? The fact that I get fuller sooner and stay full longer than a person without a band negates "the rules" of calories in vs. calories out?  It obviously doesn't, and just for those who may not be familiar, the band is not a surgery that changes anything about how the body absorbs nutrients, just makes the stomach "think" it's smaller (this is overly simplified.)

So what's the deal? I personally don't believe that I HAVE TO eat above 1518 a day to lose weight but on the other hand, I'm not losing weight at the rate that would be predicted if any of these measurements were accurate anyway.  Keep in mind, my RMR was measured yesterday after 10 months of restricted calorie eating.  So even if it had slowed down due to the reduced calories, it hasn't slowed down so much that I'd say I believe in "starvation mode."

Sorry for the long post. The whole thing is just very confusing to me. And I think even more so, that people act like it's an exact science and they can tell you just how many calories you should be eating to lose, gain, or maintain weight ... but then they say "oh, nevermind, this rule doesn't apply to you." - it makes me skeptical about the whole thing...and confused and frustrated. 

Thanks for listening.

The "don't eat less than your RMR" thing is a theory or an approach to weight loss that some programs subscribe to. It's not a universal truth or something that science demands.

If were you, I'd stick with your surgeon's program and not take too much advice not designed for the surgically altered. For one thing, what works for someone doing traditional dieting, often doesn't work for us.

I think you've got a hint if that when you ask why, if the numbers are accurate, the weight is notnjust falling off you. There are only two possible answers: you are eating more than you think or the formulas used to calculate your RMR are not accurate. I'd vote for the later, just because it matches my personal experience (and at of a lot of MO people).

The dunk tank and body pod techniques can tell you what percentage of your weight is muscle and what is fat. That is then input Into a formula that estimates your metabolic rate. If you want to know your RMR definitively, there is test you can take that measures how much oxygen you consume in a 10 min periodmthat is much more accurate.

Or you can do what I do and just go by reality. . If I was losing 2 lb a week on a certain calorie level, I would take my exercise calories and my weight loss and use that to backtrack to my RMR.

Hey Mac... first, good luck this weekend!  Better post your race number and projected finish time; would love to see you cross the line at ironmanlive.com

I can tell you from personal experience not all RMR tests are accurate.  I did my first one at my local gym and it told me 1800+ calories for my RMR.  I new that wasn't right.  I sought out a sports nutritionist after a year of unsatisfactory results.  Her test was completely different!  I can't remember exactly what my RMR was now, but I know that my "magic number" is 1400.  She's got me on 1400 calories a day, with additional requirement for days I'm training more than 90 minutes.  She calls it an "overlay" to my daily intake.

Now, that said, everyone is different.  I have some major hormonal imbalances that we found this year (hypothyroid and hyperprolactenemia).  It was quite a surprise, but definitely an answer to my questions...   Because how does one train for a half ironman and remain the same exact weight?  It doesn't seem possible if you're eating right.  

I share this because sometimes it's not just about the formula of burning more calories than you take in. Sometimes there can be something wrong.  And if you really, truly feel like something isn't right, and you know that 100% of the time you're eating clean and working out, there has to be another explanation.  It's okay to listen to your body.  I was reluctant because of that "forumula" and the science -- I had to be doing something wrong.

But right now, sounds to me like a normal plateau right now; just a long one -- but then I'm no professional.  The more weight you lose, the longer your plateaus may become as well. 

For me, my breaking point was a year.  When nothing changed with routine after a year I went to see the endocrinologist.  Thankfully he's a runner too, so he gets where I'm at.  We're closer to resolving my issues, but it's been  a long road. 

Not sure if any of this helps... sorry to ramble.