Apart from mine of course ☺

The keynote speaker in the ‘obesity’ section was Robert H Eckel from the University of Colorado. The title of his talk was “The rationale behind obesity prevention: personal and pubic challenges”. He touched on three issues: the role of fats and carbohydrates (CHO) in obesity, the difficulty in maintaining a normal bodyweight for the previously obese and challenges and new directions in pubic policy in preventing obesity.

The role of fats and carbohydrates (CHO) in obesity

The first issue he did not go into in adequate depth to glean something really meaningful for general dietary guidelines. I suspect this was for three reasons:

1. Limited time for a hugely controversial and complicated topic
2. This topic is often best discussed with people more focussed on combining physiology with epidemiology, rather than policy with epidemiological observations
3. The data he presented was more about understanding people’s baseline CHO storage and utilization proclivities, to understand individual differences in responses to weight gain / loss and to set the stage for later data that were prevented, than to make generalized dietary recommendations.

But this part of the talk was interesting. He showed that when physically inactive and eating ad libitum, people handle CHO intake differently; some people naturally burn their CHO, leading to a negative CHO balance. Others, store, not burn, CHO when physically inactive, leading to a positive carbohydrate balance. This latter group (the storers) were, perhaps unexpectedly, protected against future weight gain. You can access the full paper here. What does this mean? A full interpretation was not given in the talk. But here are my thoughts (disclosure: I am currently a low-carb diet fanatic; in fact, I am munching an Atkins Daybreak bar right now…). Burning CHO requires insulin, or at least, is the result of insulin action. Insulin is not the evil it is made out to be – in fact, it is pretty darn vital (ask any type I diabetic). But, it does inhibit lipolysis (fat burning). Perhaps those who naturally burn CHO have naturally higher insulin levels? Or perhaps those who do not burn CHO are more insulin impaired – which is why they don’t burn so much CHO and turn to fat for fuel. Maybe if they are naturally more prone to burning dietary fat & storing CHO, they ultimately store less fat than those who stroe fat and burn CHO (it is difficult / costly to store CHO as fat) and / or they burn more body fat as their body is already ‘fat burning’? Who knows… just my suggestion.

new directions in pubic policy in preventing obesity

The third part of the talk was on pubic intervention strategies and was so-so. There was a lot of ‘we must act in childhood’ – while I have yet to see any convincing (let alone conclusive) evidence that childhood based intervention has long term effects on either BMI or adult health outcomes. Also lots of vilifying fast food (with Ronald McDonald as the poster child) which I believe is too simplistic of a view to be useful.

The difficulty in maintaining a normal bodyweight for the previously obese

However, this middle part was very interesting. It focussed on how hard it is to lose weight, and keep it off. As Eckel put it “once obesity occurs, body fat is defended”. After touching on a purely observational (but well designed study) showing (1) an association between keeping weight off and (a) avoiding fried foods (b) substituting low fat foods for high fat [yes really. Not the topic for this post, but don’t overlook that] (c) increase in strenuous activity and (d) regular ‘sweat’ sessions and that (2) this is in the context of the majority of successful weight reducers regaining all the weight within a year, Eckel examined this second issue only – that weight reducers tend to regain weight no matter how they initially lose the weight. So why is it so hard to keep weight off? Eckel showed in press data revealing structural and functional differences between previously obese and non obese, where body weight was the same between the groups. His 2008 NEJM paper showed that once you have been overweight and reduce body fat a decrease in leptin and GLP-1 and an increase in grehlin (among other factors) leads to

  • Higher appetite
  • Increased preference for energy dense foods
  • Increased CHO oxidation and so (in line with the evidence in part 1) increased fat storage (or my interpretation: decreased lipolysis or fat -burning)
  • Decreased preference for physical activity
  • Reduction in the intensity of physical activity conducted.

Being ‘reduced obese’ changes your brain and endocrine physiology. But then, even normal weight women who have liposuction replace all the lose body fat within 1 year (albeit it in different places to the site(s) of extraction). Once you get fat; once you enlarge those fat cells, it seems that your body will try to return again and again to this state. As Eckle put it:

“Brain cells come,
And brain cells go.
But fat lives on forever”.

What does this mean?

1) I would argue, that given the relative lack of success at long term obesity ‘cures’, we need to start to focus more efforts on obesity prevention. This way, if we prevent people from becoming obese, we negate the problem of a temporary cure – it may be easier to prevent obesity ever occurring than to prevent it reoccurring. We don’t know this, but it may be worth finding out.
2) Keeping weight off is difficult. There is no quick fix. You cannot go on a temporary diet and expect this to solve the problem. If you want to safeguard your health – You have to go on a permanent guard. And it will be tough. You need to constantly evaluate, revise and watch your motivation. It will likely never become easy or second nature. It doesn’t have to be miserable and it certainly isn’t impossible impossible – but it will be an everyday fight.

This brings me to something I have been thinking about for a while (and ironically, a topic of conversation between a very close group of friends, this week when I was asleep). Maintaining a low body weight is not easy. I do it, through caloric restriction or carbohydrate restriction (depending on my mood) and intense exercise. I eat a lot of bland foods fairly repetitively: I ate oatmeal for breakfast almost every day for about 3 months; I once spent several weeks starting my day with only egg white and a light laughing cow. I eat a lot of plain grilled chicken and salad; I drink a lot of water. People think I am ‘lucky’ to like this. Lucky? Like it? Heck, it is a PITA. Sure I do it, and sure it doesn’t bother me too much (and sure, I don’t like a lot of fast food restaurants) but don’t think for a freaking second I wouldn’t much rather eat (home made or restaurant) tacos, fries, pasta dishes. Don’t ever think that I wouldn’t like dessert after just about every meal or that waffles with (full sugar) syrup and fruit on top is ever not my ideal breakfast. And don’t think that eating out and consuming beautiful food is not a borderline orgasmic pleasure for me. NOT EVEN JOKING. Just see me photograph and write about all my amazing meals while traveling. I am constantly in denial (because I constantly want ice cream), with one of two free meals per week. I look forward to those meals, because I know I have earned them, and I know my abstemiousness means they won’t unduly raise my BMI.

As for exercise: people think I love it. Mostly I hate it. I hate running, I am not so keen on kickboxing and I have a sense of dread whenever it comes to plyo sessions. I do it because I want the results. I like weight lifting and zumba, sure, but quite often, lying on the couch watching movies (and yes, eating popcorn and pic n mix) would be my preferred option. When I bike home from work, I often fight the urge to call my boyfriend for a lift.

You live in a world with delicious, affordable, accessible, socially acceptable excess calories, and where laziness is only a ‘car ride between shops’ at the mall away. If you want to lose weight, if you want to keep off weight loss, you are simply going to have to put yourself through deprivation / hardship – unfortunately, even more so if you have previously been heavier. But it is worth it: stop the cycle (it’s hard to lose, so you gain more, which is hard to lose so you gain more…) and man up to saying no, to being hungry for an hour before dinner, to not watching American idol ‘coz you have to go to the gym, to having sore arms and legs, to bothering to shop and buy and cook your food sometimes, to eating grilled chicken AGAIN, to watching everyone eat cake at work but not joining in because you have already had it twice this week, to not drinking alcohol sometimes, to getting up at 5 am because you work 8-8.

You need to, to protect your health and be there for your friends and family.

NB: I appreciate obesity is NOT simply a case of lack of will power / refusal to be discomforted. This is merely a statement that I think some people would be helped by understanding, and incorporating in their fight against obesity / weight gain.