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The Basal Metabolic Rate

In my last blog on calories, I described now calorie-restricted diets do not work.  Basically, the advice to Eat Less and Move More is a cruel joke.  It doesn’t work.  People are trying and, as I said in my last blog, they lose weight for six months, then the weight loss plateaus and, in some cases, the weight even starts going up . . . on the same calorie-restricted diet.  Some will cut their calories even more and start dropping weight again – until they reach the next plateau.  Most eventually give up and return to their original weight (or more than their original weight) until the next time they try to eat low-cal . . . and get the same results.

What is going on here?!? 

It’s called the Basal Metabolic Rate.

The BMR is the number of calories your body expends to keep you alive and your systems running when you are sitting still.  As a reference point, it’s around 2,000 calories, more for men than women, and varies based on how much you weigh and many other variables.  Actually, the BMR varies a lot from day to day.  For years, overweight people have been blaming their weight on having a “slow metabolism.”  In fact, overweight people have a higher BMR or “faster” metabolism.  We believe, mistakenly, that the BMR is stable, and the only thing that changes it is exercise.  Movement beyond sitting still, we believe, is the only thing that increases the amount of energy expended.  The incorrect belief is that if you decrease the calories going in, the BMR will stay at its same level, you will be at a negative caloric balance and voila!  Your weight drops.  Same idea about exercise:  if you burn more calories in addition to your BMR, you will be at a negative caloric balance, and hey presto!  You lose weight.  If you do both at the same time, the negative caloric balance should be even greater and you should lose even more weight.

But your body is too smart to let this go on for long.  It KNOWs it’s getting less energy in and putting more out, and it doesn’t like that.  Your body resists a negative caloric balance.  It knows that burning more than you take in will eventually lead to a loss of body stores, so as your weight goes down, the BMR starts self-adjusting downward too.  Meanwhile, your body tries to get you to increase your energy (food) intake by releasing ghrelin, the hormone that stimulates hunger.  It’s not your imagination that you’re hungry when you are on a low-calorie diet.  You feel cold too because your body temperature decreases to conserve energy.  Over the long term, your heart rate slows down and your heart doesn’t beat as hard, your blood pressure drops, and your brain starts obsessing about food because your body wants you to eat.

Somewhere around six months into your weight loss, the BMR has decreased till it’s only using the calories you are putting in.  As described above, your weight loss reaches a plateau, then starts going back up, even though you’re maintaining that low calorie diet.  And instead of feeling healthy because of your lost weight, you feel hungry, tired and cold.  Body weight has a set point, like a thermostat, and it resists change.

The mystery of the body weight set point works in the other direction too.  Your body doesn’t want you to GAIN weight either.  You can deliberately overfeed yourself and the BMR will increase, trying to burn up all those extra calories.  The body does its best to get you to stop eating.  It releases satiety hormones – cholecystokinin and Peptide YY – plus stretch receptors in your stomach that tell you that you’re full; you can’t eat any more.  It’s really HARD to gain weight rapidly and even harder to keep it on.  When you return to your normal diet, you immediately drop the extra weight and get back to your set point. 

So can the set point be changed?  It turns out it can and that is not a good thing.  The sad fact is that once your BMR adjusts lower, it will stay there.  So if you go back to your normal diet, you’ll end up weighing more than you did before you started the calorie-restricted diet.  People who won The Biggest Loser competition gained all their weight back and six YEARS after the contest, their BMR remained at the lower rate and did not recover.

That’s why I call the Eat Less/Move More advice a cruel joke.  It doesn’t work, and even works against you.  Yet many doctors persist in giving this advice.  When you don’t lose weight, they assume you didn’t follow that advice.  If you end up weighing more, they think you must be eating more.

What makes the Eat Less/Move More advice so cruel is because we already have medical evidence that it doesn’t work.  This evidence is decades old.  The Minnesota Starvation Experiment in 1944 and 1945 proved it.  A group of men were put on a calorie-restricted diet for more than six months, and when the plateau happened, the experimenters decreased the calories even more.  This was back before they had ethics committees to ensure appropriate treatment of subjects of medical experiments.

The results:  the subjects experienced profound physiologic and psychologic effects, but the effect that most concerns this talk is that the study predicted that the subjects should have lost an average of 78 pounds.  Instead they only lost 37 pounds.  And, as I said, the experimenters had to keep lowering the caloric intake to get them to lose that much.  All body functions that require energy experienced a 30 to 40 percent reduction.  And when the subjects were allowed to eat again, they gained MORE than they lost.  (If you want more information on this study, you can read “The Obesity Code,” by Dr. Jason Fung.)

So what DOES work for weight management?  Medical evidence shows that multiple counseling sessions are the most effective, between 12 and 20 sessions.  That’s definitely more than being told to Eat Less and Move More.  And it’s what we offer in the GFM Weight Management program:  16 counseling sessions over eight months, along with NO calorie-restricted diet.  If you have been following my blogs, you may be able to guess what else comes with the counseling sessions.  Log on to gfmweightmanagement.com to set up a free consultation with a body composition analysis.  Or call 816-427-5320 to make an appointment.  We’re waiting to help you.

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