Saturday, March 2, 2013

CALORIES IN VERSUS CALORIES OUT



Ask anyone and they'll tell you the solution for obesity. Eat less; move more. Our collective weight problem would go away if all the overweight people just quit eating more calories than they burn. Couldn't be simpler.

There are 4,086 calories in a pound of fat. Divide that by the 7 days in a week and you get 584 calories. So if you eat 584 calories less per day you will lose a pound a week. If you continue to eat 584 fewer calories every day for a year you will lose 52 pounds. In 10 years, you will lose 520 pounds. In 20 years you will lose 1,040 pounds. Doesn't sound so logical anymore, does it?

Consider this: A person who is 50 pounds overweight is wearing 204,300 calories of fat. That is enough calories to live on for 6 months. So why does a fat person get hungry?

Our bodies have a set point based on hormones that determines how much we weigh. The hormones tell you when to eat and when to stop with hunger signals. To change the set point you must change the hormones. Insulin is the master hormone. It is released in response to eating carbohydrates and it signals the body to store fat.

When you eat fewer calories and/or burn more with exercise, your metabolism, sensing that you are going through a famine, slows down to conserve energy. You will become more sedentary, your body temperature will drop, your energy level will go down, and your weight loss will slow down or stop.

By limiting carbohydrates, you can reduce your ability to store calories as fat. In spite of what you may hear from the critics of low-carb, I can assure you that the second law of thermodynamics is fully accounted for in the equation. All the energy goes somewhere, just not to your belly or your backside. We might be able to predict how much gasoline a finely-tuned car would use to travel a certain distance, but the human body is not a closed system like an engine. And the car won't help you reach your destination by adjusting its rate of fuel consumption to make sure you get there.

How much fat you accumulate is not determined by how many calories you eat versus how many you burn, but by how the nutrients in those calories affect the hormonal regulation of metabolism. If a food stimulates the release of insulin, it is more likely to be stored as fat. If it doesn't, it is more likely to be used as energy. The metabolism of an obese person is obviously biased toward saving calories as fat rather than spending them as energy, but that can be modified by dietary choices.

Most people believe in the calories-in-versus-calories-out hypothesis because they think they have witnessed it with their own eyes. Shows like The Biggest Loser perpetuate the myth. You may have read about a study of the contestants on the show conducted by Darcy Johannsen et al, who reported that by the end of the 30th week, the participant's had slowed their metabolisms by 504 calories more per day than would be expected by their weight loss. That means that by losing weight the eat-less-move-more way, these big losers now have to eliminate the equivalent of one meal a day compared to what they ate before the intervention just to stay at their original weight. www.weightymatters.ca/2011/02/biggest-loser-destroys-participants.html.


A more recent (2012) study from Johannsen's team titled, Metabolic Slowing with Massive Weight Loss despite Preservation of Fat-Free Mass, investigated whether exercise during weight loss would prevent a drop in metabolism as long as the subjects lost fat but retained non-fat mass. http://jcem.endojournals.org/content/early/2012/04/24/jc.2012-1444.short This is the conclusion from the study: "Despite relative preservation of FFM (fat-free mass), exercise did not prevent dramatic slowing of resting metabolism out of proportion to weight loss...."

The next time you hear someone bemoaning the fact that "diets don't work," you'll know why.

"Obesity is a growth disorder just like any other growth disorder. Specifically, obesity is a disorder of excess fat accumulation. Fat accumulation is determined not by the balance of calories consumed and expended but by the effect of specific nutrients on the hormonal regulation of fat metabolism. Obesity is a condition where the body prioritizes the storage of fat rather than the utilization of fat....
The energy content of food (calories) matters, but it is less important than the metabolic effect of food on our body."
~~Dr. Peter Attia,
 Here is a previous post on the subject: http://carbwars.blogspot.com/2008/01/biggest-loser.html

Post Scripts:
1. A Reuter's story (March 7, 2013) reported that a survey from the Centers for Disease Control and Prevention (CDC) showed that US calorie consumption has gone down for the last 10 years but obesity has risen. The co-author of the study said, "It's hard to reconcile what these data show, and what is happening with the prevalence of obesity," but that didn't keep him from trying. He never considers that his basic beliefs about what causes obesity might be flawed. The findings appeared in the American Journal of Clinical Nutrition. Here is the article: http://reut.rs/WvGhcO

2. The Journal of the American Medical Association (June 2012) reported about a clinical trial from the Boston Children's Hospital conducted by Dr. David Ludwig. Ludwig et al put obese subjects on a starvation diet until they had lost 10 to 15% of their weight in order to replicate those who are pre-obese for testing. They fed the subjects one of three different diets; one diet was low-fat/high carb; one was low-glycemic; and one was low-carb/high fat and protein. All three diets contained the same number of calories.

The results: the low-carb group burned 300 calories more per day than the low-fat group and 150 more than the low-glycemic group. Gary Taubes had this to say about the study: "If we think of Dr. Ludwig's subjects as pre-obese, then the study tells us that the nutrient composition of the diet can trigger the predisposition to get fat, independent of the calories consumed. The fewer carbohydrates we eat, the more easily we remain lean. The more carbohydrates, the more difficult. In other words, carbohydrates are fattening, and obesity is a fat-storage defect. What matters, then, is the quantity and quality of carbohydrates we consume and their effect on insulin....More research is necessary to shore up this finding, but, at the moment it would appear that not all calories are created equal...."
www.livestrong.com/article/559435-know-thy-enemy-carbs/#ixzz2NieQ9q2y
Image above from Wikopedia.
(C) 2012, Judy Barnes Baker, www.carbwars.blogspot.com

10 comments:

J. said...

Did you know that the links on your side bar don't work? Just thought I'd mention that. Some of those topics sound interesting to me. Thanks for the information on calories in versus out.

Jenny

Judy Barnes Baker said...

Thank you, Jenny! Try them again, I think I've got them working now.

Brad said...

I've been looking for a way to explain to friends why I'm not quite sold on the calories in vs calories out model. I think I'll start by trying the same thought experiment you did at the beginning of the article (over 1000 pounds lost over 10 years) and if that doesn't work I think I'm just going to send them to this post. Thanks for the great resource!

Judy Barnes Baker said...

Hi Brad. If you and I don't convince them, send them to the link under the quote to Dr. Attia's article for the scientific explanation.

Judy Barnes Baker said...

Here's more evidence that the kind of calories matter more than the number, but they just can't see it.

"Despite obesity rise, U.S. calories trending downwards"
http://reut.rs/WvGhcO

Fred B said...

great discussion!
I also remember , though, data showing that the sugars consumption has leveled off and even gone down in various regions (USA HFCS and Europe Sucrose), yet obesity has remained on the rise.
It might be interesting to elaborate on what macronutrient combinations do on energy exchange and partitioning.

Judy Barnes Baker said...

Fred, if only sucrose and high fructose corn syrup consumption has gone down, it would have little if any effect on actual sugar in the diet. Most products that boast "sugar-free" just replace refined sugars with other sugars, such as concentrated fruit juice, agave syrup, honey, or some other real sugar. Remember too, that starch is quickly converted to glucose as soon as it is ingested, and our health organizations are all urging us to eat more grains and starches, not less. I haven't seen any data that suggests that the general population is eating fewer carbs (except maybe in Sweden).

Judy Barnes Baker said...

Fred, here's a study done way back in 1956 that shows what happens when the percentage of macronutrients is the only variable in the diets tested: http://www.scribd.com/doc/28131415/Kekwick-Pawan-1956-Lancet

Anonymous said...

Exactly how many grams of carbs do you recommend for weight loss?

Judy Barnes Baker said...

Anonymous, you have to discover that for yourself, as everyone is different. Most low-carb diet plans suggest starting very low, at about 20 net carbs per day; some plans start at 50 Net. (Net means carbs minus fiber.) Then you gradually raise the amount as you continue to lose slowly until you reach your goal. You can then increase the carbs until you find how many you can tolerate without regaining.

It is best to get a book, such as Atkins, Protein Power,etc., and follow its advice exactly to be sure you do it right. It isn't all just about the numbers, as some foods are best avoided and others are encouraged.

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