The idea that people with a tendency to be fat have a lower base metabolic rate than others is probably a myth, yes. But that doesn't mean that there isn't a genetic component to obesity. Here is a report of a study which seems to indicate that the so-called "fat gene" influences your weight not by making you burn fewer calories, but by giving you a greater appetite. So "calories in, calories out" still works, it is just that some are genetically predisposed to put more calories in.
And if you read further, you'll see that while the genetic component exists, it doesn't account for all that much. Those with the "fat gene" were on average only 3kg heavier than those without. So we're not talking about the difference between 150 and 300 pounds, here...
A muscular person can have a higher basal metabolic rate because muscle burns more fuel than fat.
Unless you have a disorder your metabolic rate is primarily dependent on your weight, your muscle mass, your physical activity, your age, and the thermic effect of food (proteins take more energy to process than fat).
You can slow your metabolism down with a starvation diet, because the body is conserving energy. You may feel cold, you may feel that you have little energy so you don't exercise. You are forced to conserve energy. This can lead to a vicious circle because you will lose muscle mass which will lower your metabolic rate even more. So, if you start eating like you did before you can overshoot your initial weight because your metabolic rate has slowed.
Drugs can effect your metabolism, some antidepressants for example. Diabetes can effect your metabolism. Genetics effect you metabolism. Environment effects your metabolism. Metabolic disorders can effect metabolism, but they aren't common.
Last edited by goldfinch; 09-29-11 at 11:24 AM.
An interesting read showing possibly a counterpoint to the above http://www.ajcn.org/content/82/5/941.full
Summarizing as best as I can (anyone wanting the whole picture should evaluate it themselves), the greatest cause of variation in basal metabolic rate between individuals is fat free mass, which they said is consistent with previous studies. Fat mass played a much smaller role.
The apparent implication is that lean mass takes more energy than fat mass. Five times as much. However the researchers also caution that it is a statistical model not a physiological one and there are many possible factors at play.
The researchers found an enormous variation which is not explained by differences in body composition (lean vs fat), age or sex. It was 26% of the variation. I gather that's a fairly standard result, and although this residual variation isn't explained by current studies (according to the authors) I'd guess this is where the idea of genetic factors come from.
Like I said, the interested reader should evaluate it himself since I may have mashed the study thoroughly.
Sounds like the skinny guy "naturally" has a higher activity level. IE, he kept climbing up to get different tools, while you tried to think out the most efficient path... I would suspect this is a pattern of behavior for both of you.
I suspect that his pattern is what gives him a higher metabolism rate. BTW, nothing wrong with your approach, but it is likely why your bodies metabolic rate is lower than his.
But the punchline of his story was that he forgot that dietary calories are actually KiloCalories, so 1L of ice water burns only 37 kCal, and you'd have to drink hundreds of liters of ice water to have any significant effect! Oopx!
Last edited by RubeRad; 09-29-11 at 12:06 PM.
In Thomas Bouchard's twin studies, groups of identical twin men were fed 1000 fewer calories than the supposed amount that was needed to maintain their starting weight. Some lost as much as 20 pounds in a month, some as little as 4. The only constant was that whatever one twin lost, his identical twin lost about the same amount.
He makes me hate life sometimes.
There was an article in the last week, that I think I saw linked in BF somewhere, where new studies are saying that the 3500 KCal = 1 lb of weight loss is not true, and the more accustomed to exercise one becomes, and the lighter one becomes, the 3500 starts to climb dramatically. It was interesting, and described causes for many of the weight plateauing things that people experience in trying to shed pounds (I have been stuck in one for 10 months).
And there is the discussions of digestion that say lots of small meals beat out fewer large ones. If all input - output then frequency of input should mean nothing.
No one knows the real, 100% answer, and we should all embrace an inefficient life style. Go Jethro!!!!
The problem is partly one of a changing baseline. The more weight you lose the less calories you need because you are not maintaining as big a body.
Last edited by goldfinch; 09-29-11 at 09:03 PM.
Last edited by jimnolimit; 09-30-11 at 03:35 AM.
I was confined to the cab of my combine harvesting soybeans yesterday. Rather difficult to be inefficent. I will say a couple years ago and 200 lbs heavier this would have wore me out. For the naysayers out there, What's the harm in this inefficent lifestyle? I'm not saying this is some magic cure. If anything it keeps one focused to be more active.
A couple weeks back I had a day off and was bringing the laundry upstairs to be put away. I decided to do it two pieces of laundry at a time. Going up and down stairs for 30 minutes is pretty inefficient.
I havent been thinking of it as being inefficient (though I probably will now). but i have been trying to find the harder way to do things lately.
-Bring the 50 lb bag of dog food back and forth from the garage every time I feed the pups instead of bringing the bowl back and forth
-When cleaning, move EVERYTHING (counch, TV, tables, curtains, etc)
-get an exercise ball instead of a chair for the dinner table (and no base)
-shovel/rake something outside. Find an excuse
-throw the kid on my shoulders anytime we go anywhere
I'll bet each pair of twins had different BMRs and RMR's...
And, the lighter one gets, of course they'd have different BMRs and RMRs... It only take X calories to move a person from point A to point B if they weigh 160lbs. It takes X+300 to move a person from A to B if they weight 250lbs...
Nothing there changes the simple math:
Calories in - calories burned = net weight gain
Believe it or not, not every thin person is fit.
And what exactly is BMR and RMR if not "low" or "high" metabolism.
They discovered that there is in fact a decrease in metabolism, resulting in about a 150 calorie a day difference. But the real big difference is that people are less active and thus burn less calories. They become too efficient:
This doesn’t mean we exercise less, either, as exercise is a conscious choice. It means we unconsciously reduce our NEAT [non-exercise activity thermogenesis] and spontaneous activity. It also means we become more efficient in the activity we do; we expend less calories for the same movement. In fact, 35% of the decrease in activity energy expenditure can be attributed to an increase in efficiency. Overall, we move around less, and we become more efficient at the movements we perform. Combined with a decrease in resting metabolic rate, we end up burning over 400 calories per day less than you would expect for someone of our same height, weight, gender, and body composition. This is not only why weight loss eventually plateaus, but also why weight is so easily regained.
The solution is activity. Maybe, as Jethro suggest, to adopt a somewhat inefficient lifestyle.
The article goes on to state:
Remember that physical activity doesn’t have to include formal exercise. NEAT makes up the majority of your activity energy expenditure, and thus has the greatest ability to impact it. In fact, walking at only 1 mile per hour will double your energy expenditure over sitting. Thus, anything that you can do to accumulate physical activity throughout the day will dramatically improve your chances of maintaining weight loss over the long haul. Even small things, like parking a car further away from a destination, or taking stairs rather than an elevator, can add up if accumulated throughout the day. But because activity can decrease on an almost unconscious level, you need to make a deliberate conscious effort to get as much activity as possible in throughout your day, every day
Last edited by goldfinch; 04-28-12 at 06:55 PM.
It does come down to calories in/calories out. It's just that the standard formulas for Basal Metabolic Rate and Active Metabolic rate are gross approximations based on averages. The only way to know how your body converts food to weight is to track your calories in and your weight, along with an approximation of your average exercise, daily.
I've found that my body actually loses weight more quickly than would be predicted by the simple rule of thumb, a deficit of 3500 calories = 1 pound lost, meaning that my metabolism is LESS efficient than normal - which is probably pretty rare for someone who's been obese several times in his life, and overweight more times. But, when I plug my age, weight, gender and activity level into the BMR and AMR formulas, my weight loss would be consistent either with a much lower calorie consumption, or a much higher activity level than I actually have.
However - once this calibration has been done, you've got a formula that gives you calories in/calories out/weight that's pretty close to exact for YOU. (I did it by simply picking a multiplier for the AMR formula that minimized the mean squared error between the weights I measure over the course of a month and the weights predicted based on my calorie intake and average exercise amount).
Using this, I've been able to predict my weight to within half a pound, 30 days in advance, with a mean squared error of less than a quarter of a pound. If that's not deterministic, I don't know what is.
L'asino di Buridano...
Try being someone with hypothyroidism. Thyroid controls metabolism, and even on synthetic thyroid hormone...losing weight is a huge struggle.
4 years ago I was a competitive cyclist who was laying down nearly 10,000 miles a year and was working in a machine shop where I spent my days tossing around and wrestling with steel, I hit the curb at 155 pounds, could dead lift twice my weight and had 20 inch legs on what is a five foot nine frame. Before I started working in such a physically intense job my weight for decades had been a very steady 140-142.
My calorie intake to maintain my body weight while cycling and working at a desk was 4000 calories a day and I bumped that up to 5000 a day to gain weight when I started working in the machine shop and I gained 13 pounds of muscle.
An injury forced me to quit that kind of work and has reduced my activities and my mileage in my best year since the accident was 6000 miles but another injury in December has really slowed me down and my weight has climbed from that 142 I had returned to, to 155 pounds and that extra 13 pounds isn't muscle.
I have a high base metabolism and can experience hypoglycaemic episodes if I do not eat regularly but with a lack of activity and a reduced calorie intake, my body will gain weight it does not need.
For many people the mere act of being sedentary for short periods will alter your body's metabolism and insulin levels and cause a sharp drop which will make your body store fat although some people are less affected by this.
Our bodies are designed to move and in moving and matching our intake to our activity levels we should be able to maintain a balance and healthy weight but slow us down and take in more than you need and we will gain unwanted weight.