Childhood Obesity May Be Caused by Missing DNA

[Uncayimmy]

That's one point. Plus you have to correct for a decreasing prevalence of malnourished, underweight kids during that time period.

What was the rate of malnourished, underweight children in the USA during the 1960s?

But either way, my position is not that the childhood obesity epidemic is completely fictitious, but rather just that the actual change in the incidence of obesity in kids over the past few decades has been vastly overblown by the media.

Here's the thing: No child should be obese. Period. I'm not saying anybody "should" be obese, but it's a much bigger problem if a child is obese.

* Children are growing, so much of the calorie intake is used to build "good" mass (bones, muscles, etc). We all have to adjust are calorie intakes once we stop growing. A child who is putting on excessive fat while at the same time growing her body will encounter a much more serious problem when she gets older.

* Children have the most free time and opportunities for exercise compared to adults. We all encounter drop-offs in exercise as we grow up. Fat and obese children will encounter more serious problems as they age because their "baseline" is so much lower.

* More fat means less lean muscle which means a lower basal metabolism which means as they get older, they will actually need fewer calories than a child who is fit. Couple this with less exercise and excessive eating habits, and it's a recipe for disaster.

* There is control by the parents because the kids don't shop for food and the parents have influence on the physical activities. It's a lot harder for adults because they have to make all these decisions on their own, so when a child has a weight problem despite the assistance/training of their parents, it's a bigger concern.

In other words obese children are setting themselves up for major difficulties in life. And the merely "fatter" children are greatly increasing their odds of becoming obese as they age.

I also think you fail to understand how difficult it can be to see fat on a kid. Remember, we're talking about percentages of body fat here. Take a cube that is "1" on each side. The volume is 1 and the surface area is 6. Let's double the volume (weight) to 2. The sides are now 1.26, which is about 7.5 square units.

So, let's consider a 10% increase in body fat on our cube. The smaller cube is going to be a 0.1 increase spread over 6 square units. That's 0.016 units of fat per square unit. The larger cube is going to be 0.2 spread over 7.5 square units, which is about 0.026. That's 61% more fat per unit of surface area on the larger cube.

So, think about adults. A 180 pound man is twice the weight of a 90 pound kid, but he's not 10 feet tall. It's a lot easier to see a 10% increase in body fat on the man than it is on the kid because the kid has proportionally more surface area per unit of volume. So, if you're going to base your analysis on visual inspection, you need to keep in mind that "noticeable" fat on a child indicates a more serious issue than it would on an adult.

ETA: I used to be very athletic and did a lot of training. I used to track body fat using calipers. I'm a bit over six feet tall worked out heavily with weights, so I had plenty of muscle. My ex trained with me for a while. She was five feet tall, fit and thin (and flat chested). I never attempted to become "ripped" because that's a vanity thing. I trained for strength and sports where an extra few pounds of body fat made no practical difference so long I as not "fat" (think NFL quarterback). Anyway, my ex used to get really frustrated because her percentage of body fat was almost always higher than mine even though everyone would agree that she certainly appeared leaner. The calipers don't lie.

 

[Skeptical Greg]

...
http://junkfoodscience.blogspot.com/2008/02/how-weve-came-to-believe-that.html

Interesting story, but it is about healthy adult males who were first starved, then allowed to regain their weight..

It has little to do with children who are allowed to get fatter and fatter as they grow older..

 

[Pup]

And a good JFS post on the issue:
http://junkfoodscience.blogspot.com/2008/02/how-weve-came-to-believe-that.html

I don't get that article. For example:

They were put on calorie-restrictive diets of about 1,600 calorie/day, meant to reflect that experienced in war-torn regions, for 3 months. They dieted to lose 2.5 pounds a week to lose 25% of their natural body weight.

Someone genetically predisposed to obesity will become obese independent of their caloric intake, he explains

Then some people on a 1600 calorie diet should have gained weight, right? Perhaps the sample of 40 was too small, but still... where are the photos of obese prisoners of war or concentration camp survivors?

I realize that he's saying people have individual optimum body weights that they gravitate toward, and while that may make someone who's 20 pounds over their supposed "ideal" weight worry less about it, what happens to the person whose natural weight is 200 pounds over the ideal? It'll be hard for them to be healthy and at their natural weight. But telling them that regardless of how they reduce their caloric intake, they'll always be obese, would be discouraging, not encouraging (besides not being true).

[on the 1600 calorie/day diet] The men’s resting metabolic rates declined by 40%, their heart volume shrank about 20%, their pulses slowed and their body temperatures dropped. They complained of feeling cold, tired and hungry; having trouble concentrating; of impaired judgment and comprehension; dizzy spells; visual disturbances; ringing in their ears; tingling and numbing of their extremities; stomach aches, body aches and headaches; trouble sleeping; hair thinning; and their skin growing dry and thin. Their sexual function and testes size were reduced and they lost all interest in sex. They had every physical indication of accelerated aging.

Some of those sound more like vitamin or mineral imbalances than symptoms of merely low calories, such as visual problems and ringing ears. Admittedly the study was done in the 1940s when that may not have been recognized, but the article doesn't seem to take into account that it might have affected the results.

I'm torn on these kinds of topics, because I realize it's not as simple as telling someone just to eat less, any more than it's as simple as telling someone with OCD to just stop washing their hands so much. But on the other hand, if it's true that

The heritability of obesity is equivalent to that of height and greater than that of almost every other condition that has been studied,

then the genetic make-up of human beings has either changed in the last fifty years, or obesity really does have more of a behavioral component than the article would indicate.

 

[kellyb]

if it's true that


Quote:
The heritability of obesity is equivalent to that of height and greater than that of almost every other condition that has been studied,
then the genetic make-up of human beings has either changed in the last fifty years, or obesity really does have more of a behavioral component than the article would indicate.

The change over the past 40 or so years is an average 7-10 lbs. That's it. The increase in consumption of sugar sweetened drinks is almost definitely a behavioral factor (perhaps the biggest one), and then you have more people on medications that cause weight gain, and an aging baby boomer generation.
But either way, 7-10 lbs isn't the difference between heavy people and skinny people that you observe when you're looking at a crowd of various body shapes.

Then some people on a 1600 calorie diet should have gained weight, right? Perhaps the sample of 40 was too small, but still... where are the photos of obese prisoners of war or concentration camp survivors?

She overstated the evidence there. The effect is that if you put heavy people on a moderately caloric restrictive diet, their metabolism just slows down and there's no weight loss. Weight loss can be induced with more extreme caloric restrictions, but that's where you see the weirdo side effects.

I realize that he's saying people have individual optimum body weights that they gravitate toward, and while that may make someone who's 20 pounds over their supposed "ideal" weight worry less about it, what happens to the person whose natural weight is 200 pounds over the ideal? It'll be hard for them to be healthy and at their natural weight. But telling them that regardless of how they reduce their caloric intake, they'll always be obese, would be discouraging, not encouraging (besides not being true).

I'm not entirely sure if genetics accounts for morbid obesity at all. But unfortunately, there aren't any behavioral interventions that have proven effective long-term even for that subset of the population.




On the subject of the childhood obesity epidemic, I looked up some of the more surprising evidence:

http://ukpmc.ac.uk/articlerender.cgi?artid=4185

Objective To examine adolescent food consumption trends in the United States with important chronic disease implications. Methods Analysis of dietary intake data from 4 nationally representative US Department of Agriculture surveys of persons aged 11 to 18 years (n = 12,498). Results From 1965 to 1996, a considerable shift occurred in the adolescent diet. Total energy intake decreased, as did the proportion of energy from total fat (39%-32%) and saturated fat (15%-12%).

The total energy intake observed between 1965 and 1996 was below recommendations and decreased with time in each age and gender group. Overall, energy intake declined 17% during this 30-year period.

So, 17% fewer calories and lower fat diets now compared to the 60's.


http://www.cdc.gov/Pcd/issues/2005/apr/pdf/04_0039.pdf

Walking or biking for transportation can expend a large
amount of energy, but active transportation is not a major
source of physical activity for youth, averaging eight minutes
a day in 2001, with little change over the past few
decades. For adolescents, there was no clear trend in physical
education during the past decade, but there are no
data for after-school and day-care programs, which have
become more important as children spend more time away
from home. For younger children, time spent in organized
sports and outdoor activities increased by 73 minutes per
week between 1981 and 1997.

Figures 2 and 4 are interesting, too.

And at the end, in the discussion section they say:

However, food consumption patterns
have changed dramatically while youth physical activity
patterns have not. In fact, the data generally show fewer
changes in physical activity — changes in time studying
at home, participating in exercise, or taking part in high
school PE — than commonly thought. Changes went in
the opposite direction, even if at a minimal level — less
television watching and more active transportation time

Someone upthread said:

* More fat means less lean muscle which means a lower basal metabolism which means as they get older, they will actually need fewer calories than a child who is fit.

That's actually a myth:

http://adc.bmj.com/content/85/1/73.abstract

OBJECTIVE To study the effect of body composition on average daily metabolic rate (ADMR) and basal metabolic rate (BMR) in adolescence, and to examine current BMR prediction equations.

STUDY Dutch adolescents were pooled with previously reported American and British subjects (n = 90 overall). BMR and ADMR were analysed by multiple regression.

RESULTS Fat-free mass, BMR, and ADMR were higher in the obese than in the non-obese group (mean (SD): 53.2 (10.7) kg, 8.35 (1.57) MJ/d, and 13.64 (2.78) MJ/d, compared with 41.0 (8.1) kg, 6.42 (0.94) MJ/d, and 11.16 (2.21) MJ/d, respectively). BMR remained higher when adjusted for fat-free mass, age, and sex. ADMR adjusted for BMR was similar in the two groups. WHO equations overestimated BMR in obese boys and underestimated BMR in non-obese boys.

 

[Uncayimmy]

The change over the past 40 or so years is an average 7-10 lbs. That's it. The increase in consumption of sugar sweetened drinks is almost definitely a behavioral factor (perhaps the biggest one), and then you have more people on medications that cause weight gain, and an aging baby boomer generation.
But either way, 7-10 lbs isn't the difference between heavy people and skinny people that you observe when you're looking at a crowd of various body shapes.

In 1960 there were 10 men who weighed 150 pounds each. In 1970 there were 10 men who weighed on average 157 pounds. Would you notice any differences in a group photo? It depends, doesn't it? If 8 guys weighed 150 pounds and two guys weighed 185 pounds, I bet you could spot them. And that 35 pound weight gain would put those two people into the obese category based on body fat percentages (assuming it wasn't muscle, blah blah blah).

She overstated the evidence there. The effect is that if you put heavy people on a moderately caloric restrictive diet, their metabolism just slows down and there's no weight loss. Weight loss can be induced with more extreme caloric restrictions, but that's where you see the weirdo side effects.

You're oversimplifying things as well and ignoring some major gaps. There is some merit to the idea of set point weight. From an evolutionary perspective it makes perfect sense that animals adapted to famine by reducing body metabolism. Those animals that didn't died sooner and were less likely to reproduce successfully.

It also makes sense that during "feast" periods animals would adapt by reaching a certain size and then naturally stabilize. If you become too fat, it makes it difficult to hunt, gather food, and escape predators (not to mention other health risks). Given increased rates of reproduction during these times, it's less likely that animals who kept getting bigger and bigger would have a chance to be selected out, but I'm sure it happened somewhere in the chain of evolution. That's why some people continue to just get bigger and bigger until they are immobile while most seem to stabilize somewhere.

In the wild, you just don't see that many obese or particularly fat animals because feasts just don't happen that often. When we domesticate animals, we see them get fat, but you don't see feral dogs and cats that look like the fat pets that so many people have. In other words just because there is a natural stabilization point doesn't mean it's a good thing.

What people like to call a "set point" is really more like a "max point" because in the wild most animals never get a chance to get that fat and stay that fat. You're looking at a natural survival/protective adaptation and treating it like it's some ideal when it's most certainly not.

The other gaping hole in the set point theory is that it ignores exercise. C'mon, that's half the equation! Humans today exist in an environment that is totally different than every ancestor dating back to the first simple organisms. We expend virtually no energy gathering/hunting food, escaping from predators, traveling/migrating or regulating our body temperatures in response to the environment.

We're fat because food is abundant and we use external fuels (oil, coal, natural gas) to do what our bodies used to do. Let's see them do their set-point research with humans left in the wild to fend for themselves.

It's bad research with faulty conclusions.

 

[Skeptical Greg]

17% fewer calories and lower fat diets now compared to the 60's.

There is something wrong with that ..

I think I found it :

" Department of Agriculture surveys of persons aged 11 to 18 years... "

Yeah, right ! They probably think Cheetos count as a vegetable ( corn ) , and dairy ..

 

[kellyb]

There is something wrong with that ..

I think I found it :

" Department of Agriculture surveys of persons aged 11 to 18 years... "

Yeah, right ! They probably think Cheetos count as a vegetable ( corn ) , and dairy ..

No. Read the full text. I linked to it.
Overall calories are down, fat consumption is down, but soda and other sugary drink consumption is up.
The net effect is a one point increase in BMI in kids under 10.

 

[Uncayimmy]

I wrote, "More fat means less lean muscle which means a lower basal metabolism which means as they get older, they will actually need fewer calories than a child who is fit."

You replied:

That's actually a myth:

http://adc.bmj.com/content/85/1/73.abstract

What's going on here is that you are not looking deeply enough. Of course, if I put on 100 pounds of fat, I'm going to need more calories to stay fat! My body will have to work a lot harder to cool itself and move itself around. It will be more difficult to pump my blood. That anyone would doubt that much larger and inefficient organism would burn more calories on idle is surprising.

But the reality is that I don't need those extra calories because I don't need to be obese. If I'm already obese and drop 100 pounds of fat (say through surgery), I will actually need fewer calories to maintain that weight than will a fit person.

Excluding obesity, if you have two kids the same size and weight with one having a higher percentage of body fat, are you arguing that the one who is not fit will burn more calories than the one who is?

 

[Uncayimmy]

The net effect is a one point increase in BMI in kids under 10.

So, what does a one point increase in BMI mean to you?

 

[kellyb]

It's bad research with faulty conclusions.

Unless it's not.
Maybe the fact that people are living longer than ever before somewhat debunks the naturalistic fallacy in this case.

 

[kellyb]

So, what does a one point increase in BMI mean to you?

Nothing?
Or maybe, greater longevity?

It definitely doesn't mean that we all need to go into freakout mode over OMG AN EPIDEMIC!!!eleven!!!

 

[kellyb]

I wrote, "More fat means less lean muscle which means a lower basal metabolism which means as they get older, they will actually need fewer calories than a child who is fit."

You replied:


What's going on here is that you are not looking deeply enough.

I thought you said:

More fat means less lean muscle which means a lower basal metabolism

Is that a true or false statment?

It sounded like you were saying "More fat means less lean muscle which means a lower basal metabolism" but perhaps I misread.

 

[Skeptical Greg]

No. Read the full text. I linked to it.

Yes, and your link informs us that the study was based on 11-18 year old's recollection of what they ate ..

Hardly scientific or reliable ..

Overall calories are down, fat consumption is down, but soda and other sugary drink consumption is up.
The net effect is a one point increase in BMI in kids under 10.

See above.

 

[Uncayimmy]

Unless it's not.
Maybe the fact that people are living longer than ever before somewhat debunks the naturalistic fallacy in this case.

That's just a useless statement on so many levels that it's just not worth addressing. You seem to have an agenda. Why not just tell us what it is?

 

[Uncayimmy]

Nothing?
Or maybe, greater longevity?

It definitely doesn't mean that we all need to go into freakout mode over OMG AN EPIDEMIC!!!eleven!!!

What's the distribution of BMI among children look like? Has it changed during the period covered? Assuming an unchanged distribution, what percentage of kids with a one-point bump in BMI will be pushed into the obese range?

 

[Fat Bottom Gurl]

Have a huge virus on my laptop and cannot log on to anything, so had to grudgingly use my desktop (can't sit on the couch and post)...harumph.

Here is the abstract on the study (in my OP) from Nature (can't get the full study as I do not have a subscription). NOte the 2nd last sentence (I bolded).

"Obesity is a highly heritable and genetically heterogeneous disorder1. Here we investigated the contribution of copy number variation to obesity in 300 Caucasian patients with severe early-onset obesity, 143 of whom also had developmental delay. Large (>500 kilobases), rare (<1%) deletions were significantly enriched in patients compared to 7,366 controls (P < 0.001). We identified several rare copy number variants that were recurrent in patients but absent or at much lower prevalence in controls. We identified five patients with overlapping deletions on chromosome 16p11.2 that were found in 2 out of 7,366 controls (P < 5 10-5). In three patients the deletion co-segregated with severe obesity. Two patients harboured a larger de novo 16p11.2 deletion, extending through a 593-kilobase region previously associated with autism2, 3, 4 and mental retardation 5; both of these patients had mild developmental delay in addition to severe obesity. In an independent sample of 1,062 patients with severe obesity alone, the smaller 16p11.2 deletion was found in an additional two patients. All 16p11.2 deletions encompass several genes but include SH2B1, which is known to be involved in leptin and insulin signalling6. Deletion carriers exhibited hyperphagia and severe insulin resistance disproportionate for the degree of obesity. We show that copy number variation contributes significantly to the genetic architecture of human obesity."

In my OP, the study is not addressing garden variety obesity, but a very minute fraction of the overall population. Getting back to the "blame" part - if these children are resistant to the usual factors that allow one to lose weight, and the parents were feeding these children normally, then yes the parents should not be blamed for the childrens severe obseity.

 

[Beerina]

So CainKane1 might still be right 99 times in 100...

That jives with another study from 15 years ago, where they measured the metabolism of lots of people, and found out that fat people just ate too damned much, and that "It's a glandular condition!" was actually extremely rare.

As skeptics we're well aware of many studies that show people constantly underestimate the amount of calories they consume.

I'd even go further and suggest that a sedentary life isn't the life we evolved to have, and that we don't really eat too much, but don't do enough.

During college, every summer working in a factory I'd drop weight like a rock with little or no change in eating. When dieting, it was effortless to lose a pound a day, which was not just water weight because it kept up.

Combine that with plentiful, cheap, greasy, fatty food, engineered to be that way for the taste, and the problem even gets exacerbated.

 

[Uncayimmy]

The problem still comes back to "you don't create something out of nothing." The notion that some people are "resistant to the usual factors that allow one to lose weight" makes no sense to me. It's energy consumption and expenditure.

One possible way this theory might work is if typical humans extract a relatively small percentage of the available energy from food. If the average person extracts 800 calories from every 1,000 consumed, then I could see how somebody who gets all 1,000 will put on weight. However, if they reduce their consumption by 20%, then we're even again. Another possible explanation is that the body has a self-regulating mechanism where excess calories consumed are flushed out of the system. I have seen no evidence for either case.

Have you ever seen the shows on obesity on Discovery Health? Several obese people have come right out and said, "Obese people lie. We're just like addicts." I've seen people going through in-patient treatment having food smuggled in.

I have no doubt that compared to myself it's harder for some people and easier for others to maintain a healthy regimen of diet and exercise. Back when I was seriously into fitness, I had a number of people ask for my assistance both in gaining and losing weight. The first thing was to track food intake. I made these simple cards where all you had to do was scratch out numbers of calories consumed in increments of 50. In every single case the "too skinny" group ate less than they thought and the "too fat" group ate more than they thought.

I just don't see how you can escape the laws of physics. If they want to say that certain people are "resistant" to diet and exercise, they need to demonstrate the mechanism because humans don't turn air, sunlight and water into fat.

 

[Skeptical Greg]

...and the parents were feeding these children normally, then yes the parents should not be blamed for the childrens severe obseity.

If they are not normal children, then they shouldn't be fed normally ..

The parent is always responsible for their children's health ..

You don't watch your child grow morbidly obese, without taking steps to reverse it..

 

[Fat Bottom Gurl]

If they are not normal children, then they shouldn't be fed normally ..

The parent is always responsible for their children's health ..

You don't watch your child grow morbidly obese, without taking steps to reverse it..

I'd say we are all now speculating on just what these parents did or didn't do.