The Cause of Obesity - Part 3
January 29 2012
This is the last post on this topic (Part 1 & Part 2). Lot of people made comments and there were a lot of discussions on a few different blogs and forums. I had a posted in a couple of other forums too. I knew very well that I will get a lot of criticisms, but I am sure these articles will will make a lot of people think twice before they make comments about obesity and obese people.
This a very important topic and I admire all those passionate commenters who took the time to express their concerns and opinions. In this article, I will be replying to some of the commonly asked questions about the articles
1. This is just a matter of how you view it. Environment is required for obesity. Look at the concentration camps and tell me how many people are obese, Anoop?
This is one question that was raised lot. This is almost a knee-jerk response from people. It is true that environment is required. I don't think anyone will argue against it. The concentration camp is just an example of the “absence” of environment or the “lack” of environment. If we don't give food, nobody will be obese, or for that matter, nobody will be even healthy or normal weight!
What we are concerned is when everyone is given free access to food (or the same environment) why only a few people become obese? Here is an example I gave to one of the posters. I usually don't try to make analogies because they are often wrong, but I feel this gets the point across.
Imagine you plant Sequoia tree (one of the tallest trees) and other trees in a plot which has the same type of soil (same environment). After a few years, you see the sequoia tree taller than others. Are you going to say the difference in tallness of the trees is because of the soil (environment) or simply because it is the sequoia tree (genetics)? Almost 99% percent of people would simply say it is the sequoia tree. We are not going to sit and argue if it weren't for the soil the tree wouldn't be this tall. But when it comes to obesity, we just can't see the obvious.
2. Just like other genetics disorders, obesity will not manifest if there is no environment.
“Every genetic disorder is 100% genes and 100% environment”, by Ken Rothman (one of the epidemiological greats). A classic example quoted is the phenylketonuria (PKU), a genetic disorder which characterized by a mutation in the gene for enzyme rendering it nonfunctional; this is about as 100% genetic as a disease can get! If it goes untreated, the kids develop mental retardation and brain damage. Nevertheless if there was no phenylalanine given - a phenylalanine free-diet, there would be no PKU, so one could argue it is 100% environmentally determined.
The huge mistake in comparing PKU (or other genetics diseases) and obesity is that in PhenylKetone Urea (PKU) kids are not “hungry” for phenylalanine.
In obesity, hunger is THE fundamental problem. We used to believe that people became fat because they had a slow metabolism or they spent less energy (Non-exercise activity thermogenisis). Now we clearly know that Leptin, Ghrelin and all other staggering complex of hormones are working at the hypothalamus by increasing or decreasing appetite. When leptin deficient kids who have a voracious appetite are treated with leptin, the first thing to drop is their hunger. Kids with Prader-willi syndrome eat from garbage cans because they feel they will die if they don't eat. Bariatric surgery works so well because it is bunting their appetite for some weird reason. People who lose a lot of weight gain weight back because they are primarily hungry.
So obesity is not a “passive” genetic problem where the genes are just sitting there in the background silently until they see food. People eat because they are hungry.
3. Obesity is all about people eating more. If obese people eat less and move more, they will not be obese.
Obese people are fat because they eat too much. Everyone knows that. The question is why are these people doing it in the first place? Or why are 70% of the non-obese not doing the same? Is it lack of will power or laziness when both have access to the SAME toxic environment?
If it is not biology then it should be lack of will power or laziness. If that's the case, we have a bigger issue here. Obese people are lazy and are incapable of changing habits and behaviors. This is so earth shattering discovery that is worth the Nobel Prize in the field of psychology.
4. Ok. Obesity is largely genetics. But there are a lot of people who lose weight and keep it off, right
And this is the problem with anecdotal evidence: looking at a few positives and casually extrapolating to everyone. Nobody wants to write about their tales of weight loss failure or struggles. People only hear (or want to hear) the grandiose tales of weight loss success in magaziines and on TV. And this is just a minority.
The negative hits never get counted or talked about. In medicine they say, “dead men never tell any tales”. In research, they count the negative hits too. There are people who are struggling very hard, but still cannot lose weight and keep it off.
Here is one commenter: How interesting! I have struggled with weight all my life. I have gone from a size 16/18 to a size 10/12 without ever going below 65kilos. It is as if my body simply will not release any more weight. Also, I recently lost 5kilos over 4 months or so, without losing any fat percentage whatsoever! Again, it just will not go! At size 10/12 I am still 35% fat, and have only ever been 40% fat at my heaviest at 85 kilos. It feels mad!
Her story will never come on a magazine or a blog. She might very well have a biology which makes it hard to lose weight and keep it off. But they are all lumped into the same category and just crucified for not working hard enough or making bad choices. This is an example of how research or science helping morality. We are the very same people who back in the days labeled schizophrenics as possessed by demons and people with complex regional pain syndrome as mad! And what helped them? Science or understanding the biology - not more or better anecdotes.
5. Twin studies show heritability of obesity to be around 60-80% (very high). So 60% of your weight is explained by genes and the rest is environment.
No. Heritability can only explain the variation between individuals within an environment. So when they say heritability of height is 90%, it means 90% of the difference between average height and extremes of height can be explained by genes. We cannot say that this percentage of the weight is due to genes or environment.
6. Everyone can get obese if they eat enough food or have access to enough calories. Look around, people now are fatter than they were in the 70's. How do you explain that?
And this is the number one reason why people instinctively question these articles.
And this is another problem with anecdotal evidence. When people say people are getting fat, they have no accurate way of quantifying the gain in weight. They are just eyeballing and making conclusions. Did they gain 10, 20, 50, and 150? Most people are talking about their 5 to 15 lbs weight they gained or saw their friend gain and extrapolating it to the effect of environment on obesity.
There is no question that people gain 10-15 lbs due to environment. You won't call that fat do you? To go from overweight category to Obese (25 BMI to 30 BMI),you have to gain around 35-40lbs. To go from normal weight to obese (20 -30 BMI), you have to gain around 75-80lbs. To go from normal weight to extremely obese (20-35), you have to gain 125lbs. But if you are right below 30, you can gain just 2-3 lbs and be clinically obese!
Do you seriously think people gain this 50-100lbs weight by “accident” if they have food around?
And it is extremely hard for people to get obese. If you think it is easy, check this documentary of people trying hard to get obese.
7. What about people who gain a lot of weight as shown in NHANES study in US?
This is a good point. For people who are already heavy (around obese), the toxic environment is making them worse. And Karky had commented on this. They are gaining 3-4 times the weight than the normal or underweight people. These are the same people who make the average weight gain on US go up and make the rest of us look fat too. This is a classic example of gene-envronment interaction.
8. This kind of gives people a cop out in that it justifies the genetic component, but it’s a bit like saying “Cancer runs in my family, all of the smokers died from it.
There are number of people on Facebook and other blogs that have made similar comments. When did we get so concerned about their health and welfare I ask? Give them a break for heaven sake.
Most obese people are often depressed, lack self esteem and live a life in an endless cycle of self-blaming. There is no other population that has been discriminated for so long, even in the 21st century. These people have been discriminated and judged everywhere, in schools, workplaces, and even by health care professionals. It is clear in research that even health professionals (also people who treat obesity) associate obese people with being “bad” and “lazy” and “worthless”. This is largely because we still think obesity is all about a personal choices and we are too cuddled up in our cognitive biases to question our assumptions.
And for all the normal people who are crying out loud, why can’t you all get a six pack? After all just like losing weight, getting a six pack is as simple eating less and working more.
9. So you are saying just lose 10-15 lbs or 5-7% of the weight?
Losing weight is extremely simple in principle, but extremely hard for the majority and maybe almost impossible for some. And this is what the research says too. IOM (Institute of Medicine) and the NHLBI (National Heart, Lung, Blood Institute) recommends this too. In fact “success” in weight loss treatments is a weight loss of >=5% of bodyweight maintained for 1 or more years.
This amount of weight loss will not bring many people even close to normal BMI. Then why it is set so conservatively? Because we know that majority of people regain almost all the weight back within 3-5 years. The IOM summarized the long term findings by saying” those who complete weight loss programs lose approximately 10% of the body weight, only to regain two thirds back within a year and almost all of it back within 5 years”. And this hasn't changed a bit even now.
We have number of studies to show that even moderate looses have significant health benefits. In fact, two of the the large multicenter trials - the DPP and the LOOK AHEAD study- has shown this.
So lose 10-15 and maintain it for 6 months. If it can be maintained without extreme difficulty, try to lose more. I am not going to sit and argue with people who want to lose more. But they should understand what they are dealing with and be better prepared.
9. People could become fatalistic in their approach to weight loss upon reading the article.
Does anyone here have a better option?
What are you goona to tell them when they fail? And most will. That since it not genetics, it is probably you; so try again. And you thoroughly deserve all the mental agony and suffering you go through and also the stigma associated with obesity?
10. Ok agreed it is largely genetics. It will not change the treatment of obesity since we cannot change genes.
Finally, everything comes down what we can do about it. I wouldn't have written this series if there were no practical applications. Just understanding the biological basis of obesity, changes everything: It changes the way we treat obesity and treat obese people.
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Obese people will set realistic goals (5-7%). Most people set weight loss goals looking at magazines or they think they have to come down to normal BMI to be called 'healthy'. If it can be maintained without extreme difficulty, try to lose more.
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People will immediately focus more on weight maintenance than weight loss. I always tell my clients that “weight loss is easy, weight maintenance is the hardest part”. People just don’t get this idea because they have no clue about the biological basis of obesity whatsoever. People will think long term, and will think more about how to maintain their weight loss than how fast they can lose the most amount of weight. The typical Before-After picture is an example of weight loss - not weight maintanance.
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People will finally stop looking for the perfect diet or bothering incessantly about whether it is fructose, crabs, fat and so forth. They will finally stop blaming their diet for failing them. There will be less tress wasted on diet books.
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Normal weight and lean people would look at obese from a different perspective - one filled with compassion and empathy.
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And for the most important part: Obese people will finally understand that it was never their fault. They will finally be free of their endless self-blaming, depression, and lack of self-esteem that they had to endure their ther whole life.
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And this world would be a much better place to live in.
Note: If you want to learn more about this topic, start with this recent presentation about Friedman about the biological basis of obesty. He discovered Leptin. The book Rethinking Thin: The New Science of Weight Loss—and the Myths and Realities of Dieting by Gina Kolata talks about the same too.
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| Sun March 18, 2012 
Anoop -
Whose guidelines are we talking about ? Are these some of the same people who told us that eating fat was making us fat ?
Quite typically obese people will lose 10-15 pounds the first week! Telling obese people to lose a comparative handful of pounds and then having them hold is, in my view, akin to watching a baby take his first few steps and then confining to the stroller.
When obese people begin to cultivate a healthier relationship with food ... good luck trying to keep the weight on them!
I do not grant this necessary correlation between rapid weight loss and rapid rebound. Indeed, one new study showed that people who lost 10% of their bodyweight rapidly were more successful maintaining than those who lost weight gradually.
I also suspect that fear of muscle loss is overstated so long as one is strength training.
Anoop | Wed March 21, 2012 
Hi Dale,
These are the federal guidelines from NHLBI proposed in 1998. They will be updating these in 2012, but I don’t see any major changes.
All that talk about cultivate a “healthier relationship” just sounds great in theory.There are lot of obese people who eat healthy and exercise, but are still struggling.
And that’s a good point. VLCD is an effective diet. But now studies have shown taking a slower route maybe better.Large part of the reason is it is easier to make lifestyle changes and stick to it if done gradually.But either way we are not really getting there.
The whole keep muscle mass when dieting is just a sound theory.I don’t think we have any study to show that people who weight trained kept off the weight longer. We trainers like to talk about it because that is what we mainly do with our clients! But it is still an upcoming area in obesity field and not studied well.
| Fri March 23, 2012 
Great Series Anoop! I had a long wait at the supermarket checkout last night and couldn’t help but notice what people had in their grocery carts. The two that stood out were older women of different nationalities that were in good shape for their age. The were probably older than they appeared. Both had their carts filled with fresh vegetables, fruits, and the chicken breast that was the feature special ($0.89/lb) this week.
I then noticed some other people in line with over-weight appearances with their cards full of convenience foods, chips, desserts, and pre-fried oven bake foods (also on special this week).
These comments are strictly on the peoples appearance. It would be interesting to see a study of random grocery shoppers to see how they would do in a fit test and maybe see some simple blood work results then compare it to their diet based on their grocery purchases.
Anoop | Sun March 25, 2012
Hi Rob,
Thanks Rob!!
And that might be the problem. They just cannot control their food behaviors which maybe driven by their genetics.
The same reasoning applies for obese people eating more. But what is making them eat more than us is the million dollar question.
And people eating chicken breasts are just the minority like us. It is not a normal way to eat for the most.
| Wed January 16, 2013 
Anoop -
Hope it’s not to late to pose another question. We know that the US has the highest obesity rate of the high-income nations, much higher than most. Accordingly, wouldn’t cultural attitudes towards eating be part-and-parcel of environment ?
America: give 315-million people ready access to food and apparently 30% will manifest obesity.
France: give the French free access to food ... and only about a third of the French will manifest obesity, presumably because it is deeply ingrained in culture to savor smaller amounts of food. What else could explain the disparity ?
Larger question: If there are fewer strictures in America against gorging, how do we know the so-called setpoint, that 10-15 pound range you talk about ? I know a gentleman who ballooned to 525 lbs. Now, I don’t expect him to become a svelte, 185-pounder, but surely he’s not consigned to bouncing around between 510 and 525 interminably, is he ?
Appreciate your thoughts ...
Anoop | Sat January 26, 2013
Hi DAle,
Never too late for any questions in Exercise Biology!
I don’t disagree. The weight gained due to environment could be due to cultural factors and such. But that is regulated by your set-point. If you think about it, most people look the same throughout their life (skinny 1s always skinny, chubby is always chubby,..). Also, even in the obesegenic environment there are people who are lean with no exercise or diet and whatsoever. If you have to go from overweight to obese, you have to gain around 40-50 lbs. People don’t accidentally put that much weight you know.
People who do balloon like that (520lb) are exceptions and do have some genetic problems.
| Sat January 26, 2013
Thanks, Anoop -
Yes, I grant that the 500-pounder is an outlier. But I do see people, from time to time who, perhaps due to some sort of traumatic event, begin to overfeed, and appear to gain weight in linear fashion for some time.
I’m talking about adults, like my thirty-year old neighbor, who tells me he gained 55 pounds over the last year after he stopped smoking.
Then there’s a friend of the family who says she gained 100 pounds, over the course of three years, after a troubling marriage.
I suppose my question is, how can such people even begin to estimate their ‘setpoint’ ? In other words, seems that gross overfeeding might have them tens of pounds over their optimal (for them) weight.
For these people, would it perhaps be prudent to steer them away from weight-loss goals and invite them to eat more intuitively (and add movement) in the anticipation that they may eventually ‘settle in’ at a somewhat lower weight ?
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