Monday, February 10, 2014

Question your assumptions about obesity, nutrition, and health

I guess it's been too long since my last rant, so here we go.

There is an epidemic in the modern world: the obesity epidemic.  But there is another widespread problem that is impeding our ability to solve the obesity epidemic: the I-already-know-it-all epidemic.  You ask just about anyone about obesity and they will tell you:

1. Eating too much and exercising too little causes obesity.
2. Obesity causes illness.
3. The way to reduce obesity-related illness is to eat less (moderation!) and exercise more.  This simply takes willpower, which fat, lazy people obviously don't have.

It seems so simple, right?  Common sense, intuitive.  But intuitive doesn't mean right!  Just take a moment to consider the possibility that all three of these points are completely wrong.

1. Eating too much and exercising too little causes obesity.

Most people claim that obesity results from an imbalance of energy, eating too much for how you exercise.  But what that explanation fails to take into account is that how much energy you take in and how much you burn are not things that you simply decide to do.  You eat when you're hungry, you exercise when you have the energy to do so.  When you have the flu and you spend all day in bed, it's not because you're lazy, is it?  No, your body's internal signalling is telling you to slow down so you can get better.  It's the same with being overweight, your body's hormonal state is telling you to save energy.  Being lazy doesn't make you fat, being fat makes you lazy (or rather, tired).  When you're trying to feed a teenager on a growth spurt, they're hungry because they're growing, they're not growing because they're hungry!  Hunger and energy are driven by your hormonal states.

Obesity is caused by hormonal disregulation (insulin is the major player, but other hormones related to hunger and satiety play a role too).  Other people have done a much better and more thorough job of describing how this works (Gary Taubes, Robert Lustig).  Go read them.  The take-home message is that consuming too much carbohydrate (and particularly fructose) is an effective way to set off this hormonal screwup.  Evidence for this explanation ranges from the molecular level to the anthropological level.  Using logic and scientific reasoning, we can infer the causal mechanisms.  We can at the very least rule out what it isn't (eating too much fat, eating too many calories).  I would reproduce all the arguments here for you, but there really is no need.  They have done all the work for me.  I really, really doubt that anyone who gets the whole way through Good Calories, Bad Calories will continue to disagree with me on this.

2. Obesity causes illness.

Obesity and serious illnesses like diabetes and heart disease are certainly linked.  But that doesn't mean that obesity CAUSES illness.  Another explanation is that that the underlying problem that causes obesity-related illnesses (hormonal disregulation) also causes obesity, possibly as a reactive/protective mechanism.  "But we all know that being fat makes you sick!"  No, we don't know that.  Fat people aren't the only ones who get diabetes and heart disease.  And there are fat people who don't get heart disease and diabetes.

3. The way to reduce obesity-related illness is to eat less (moderation!) and exercise more.  

If we're not fixing the problem, we need to question our assumptions.  If it were as simple as everyone says - eat any foods in moderation - then why do so many people struggle with their weight?  Why do more people struggle now than fifty years ago?  Exercise is great for you, but there is NO evidence that it will help you to lose weight.  Again and again, studies show this.  So what do the experts do?  They recommend even more of it!  That's not helping anyone.

I questioned my assumptions five years ago.  I had to set aside everything I "knew".  My Ph.D. ego certainly took a hit.  I was a Scientist, so clearly I understood the Science.  But I took a leap and accepted the possibility that I didn't understand.  I read and read and read and watched and listened, books and blogs and articles and interviews and podcasts.  I experimented on myself.  I ditched my low-fat whole-grain diet and my triathlons (and my creeping weight gain and loss of muscle) and I started eating bacon and eggs and lifting weights.  I got lean and healthy.  Five years and a baby later, I'm still lean and healthy.  I eat more calories and exercise less than most women I know.  I feel good, and I look good.  My heart breaks for overweight people who are constantly being told they are lazy and gluttonous.  I want to help them, not judge them.  They don't need to hear the "calories in, calories out" nonsense anymore.  They need to fix their insulin regulation, they need to let their bodies heal, they need advice that will work.

So what do I do?  I eat a diet informed by evolutionary biology, with no grains or legumes, little dairy, little sugar, no industrial seed oils, and some attention to my carbohydrate intake (more carbs when I'm more active).  I exercise briefly and intensely and not all that often, and I view it as a treat, not a chore.  I'm happy.  I'm healthy.  I've eaten this way for five years, through a pregnancy and over a year of breastfeeding.  It gives me the energy to live an active life.  My son has eaten this way since he was conceived and he's now 2 and a half.  I have never seen a stronger, sharper, healthier kid.  We are nourished, not deprived.

I challenge you to admit that you don't have all the answers, that your intuitions may be wrong.  Google anecdote after anecdote of people who have healed themselves with a paleo or low-carb approach to eating and lifestyle.  Try it yourself.  Most important, question your assumptions about energy balance and moderation.  Read, listen, learn, experiment.  Take responsibility for your own health and for the greatest health (and economic) threat of our time.  If we as individuals can't question our assumptions, get out of our rut, I fear for our future as a society, as a species.

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