Wednesday, September 4, 2013

The various factors behind the obesity epidemic

Over the past thirty years we’ve seen the levels of obesity explode in the western world - even in the face of lots of government & public health efforts to aid us in becoming thin again. Recently, many of us have become convinced we know why we got so fat, and that we also know the solution. However, in this post, I’ll point out that although we’ve come a long way, we aren’t there yet. This article is both for the people convinced “it is the calories, stupid” and for the folks who are sure “it’s the carbs/fructose stupid”.


I’m indebted to Yoni Freedhoff, Con Kolivas, Adele Hite, Denise Minger and Stephan Guyenet who’ve been thinking longer and harder about this issue than at least I’ve been able to, and who rightfully point out that dropping the carbs” is at best a partial solution, and can’t be the complete story how we got here.


So why do we get fat? Well, because we ingest more energy than our bodies are burning, leading to storage. And as much as we all hate the old dogma ‘just eat less and move more!’, this original statement remains true. Up till recently, the only reason why people thought you got fat was lack of discipline: otherwise you would just eat less and move more!




And of course, we now know this picture to be incomplete. Since obesity rates started to explode in the 1980s, there hasn’t been a massive decrease in willpower and discipline. However, in a real sense, the level of discipline is part of the equation. For example, someone able to permanently go hungry, and willing to spend hours a day on exercise, will most definitely be able to become as skinny as they want.


In the 1990s when I first read up on the theories behind obesity (since I was massively so), it was widely denied that people could have a propensity towards getting fat. Almost all fat people I know claim they eat less than their normal weight counterparts, and I knew this to be the case for me (at least mostly), but government education and popular scientific opinion at the time denied that: anyone ingesting less than (say) 1800kcal should be losing weight - with a narrow exception for folks with thyroid issues.


Since then, we’ve discovered that many people are insulin resistant, also known as ‘pre-diabetic’, and their bodies are “setup to get fat” given the low-fat diet typically recommended. There are also other reasons a body might “want” to get fat. So, the new chart becomes:



In this model, some people might be very resistant to getting fat, and only need a little bit of discipline to keep their weight under control, maybe say to lose some pounds gained over the holidays. Other people however could have a high propensity for getting fat and need to ration themselves strictly, closely monitoring what they eat and living a very active lifestyle.


We now know that the propensity to get fat is in all likelihood both an innate feature of an individual and something influenced by (historical) diet and lifestyle.


It is easily observed these days that for large fractions of the public, the level of discipline required is not sufficient to counter their propensity to get obese. But how did that happen? Enter the third part of the equation:



Our current environment is highly obesogenic. We’re surrounded by highly rewarding food and highly caloric drinks. They are everywhere, they are cheap and they are marketed heavily. It takes work to refuse the food since it is thrown at us at work, school & play.


Not all foods are created equally. Compare for example three large apples with one glass of apple juice. Both could contain the same amount of energy (if no extra sugar has been added to the juice!), but you could drink a glass of apple juice AND finish your lunch. However, try eating three large apples before you start lunch - you might no longer want it!


In the limiting case, in an environment dominated by unprocessed whole foods, you wouldn’t need discipline to stay thin, you’d need to work very hard to get fat! This is not our world however, in reality ultra-palatable highly caloric, nutritionally poor foods are far cheaper and more available than highly satiating nutritionally rich versions.


Similarly, historical obesity rates (pre-1980s) in The Netherland were three times lower than in the US. This may well be because The Netherlands is a highly walkable country where parking spaces are at a premium compared to the US (where most people get around by car).


In this way, an environment can be obesogenic based on what food is on offer, how heavily it is marketed and how much transport and work lend themselves to naturally getting exercise (which lowers obesity propensity).


There is one more step to go until the picture is complete:



You might have all the discipline in the world, but if the advice you are getting is wrong, you are expending that discipline incorrectly. So for example, if you are being told you’ll lose weight by avoiding fat, especially saturated fat, and you end up eating loads of highly processed ‘lite’ products high in sugars and refined grains but low in nutrients - you’ll have a FAR harder time losing weight than someone told to eat highly satiating whole foods lower in carbohydrates and full of nutrients.


Meanwhile, if you have little discipline, but you are getting great advice on how to make the most of it, this will get you a lot further. And if your advice is upside down (for example, if people tell you you must exercise off your excess pounds), the more discipline you have the worse it might get!


What this teaches us

Now that we have the picture complete, we can start drawing some conclusions. We know all four boxes are part of the equation: infinite discipline will lead to the desired result, as long as the advice is even slightly correct. An environment where calorie rich satiety-poor food is rare makes it nearly impossible to get fat. Finally, the propensity to get fat differs, and there are people that couldn’t get (& stay) fat even if they tried.


Meanwhile, we can consider the amount of discipline to be roughly constant. I know of no way to teach adults more discipline. I know discipline can be used for many things, and food and exercise are just two of them. Governments and media have already convinced us that if you are fat, getting thin should be your absolute #1 priority - you can’t make it any more important than that.


However, the obesogenicity of the environment can be tweaked, for example by no longer inundating people with (free or cheap) food everywhere they go, banning (for real) the marketing of food to kids, regulating the sugar content of drinks etc.


Also, we can improve the advice people are getting: the current message of low-fat eating and exercise for weightloss is just provably wrong. This means we are wasting the discipline that people proveably have!


Finally, the propensity to get fat is partially inherited (sorry!), but is also influenced heavily by what we eat today, and what we’ve been eating and doing historically. We can’t change the past, but by exercising more, rectifying micronutrient deficiencies, reducing carbs, avoiding sugar and more specifically fructose and oxidized and otherwise molested fats, the propensity to get fat can be reduced.  


Some perspective

In the paleo, low-carb, ketogenic blogosphere, there is a lot of anger about our government advice being wrong, and that removing sugar and reducing carbs will Solve Everything, since carbs drive insulin drive fat storage “qed” etcetera.


However, professionals actually working on implementing this modern advice find that while us folks all hot and bothered in the blogosphere are able to lowcarb & paleo it for the rest of our lives, it is not yet sustainable for the general population. And given the framework outlined above, we know why - if our environment is overly obesogenic, not everyone will have sufficient discipline to resist it - even given good advice.


Secondly, while the carbohydrate theory of weight gain is attractive, over the past centuries humans have eaten a lot of carbs - the larger question is why the propensity to get obese crept up so much, and to be honest, we don’t have the full answer yet. It is more than carbs. What gets us OUT of this mess (dropping the carbs) may not have been what got us INTO it.


Concluding


To make serious headway into reducing obesity (or more importantly, improving our health results!), we need to do more than banish carbs. As Yoni Freedhoff has stated, the only diet you can keep up for life is one you enjoy. Serious headway has to come from all sides: better nutritional advice, less of the wrong food and more opportunities for naturally expending energy.

No comments:

Post a Comment