Just watched the ABC Catalyst program on the saturated fat controversey. The show interviewed a series of experts about the advice we've received for years: that we should reduce our blood cholesterol level and dietary saturated fat.
Of 7 experts, the 5 telling us dietary saturated fat doesn't cause heart disease all have books and websites that make money off controversy (Gary Taubes, Stephen Sinatra, Jonny Bowden, Ernest Curtis and Micheal Eades). So while they make valid points about the limitations of the dietary fat hypothesis, I would be sceptical of the alternatives they have to offer. In contrast, David Sullivan leads a lipid research group at Sydney Uni, and I couldn't find any conflicts of interest for him. He supports the low saturated fat message, along with Robert Grenfeld (of the National Heart Foundation).
The opinions of a journalist (and doctors who need to sell books) shouldn't presented as equal to those of a leading academic scientist. I look forward to more definitive nutrition research, but for now I'll be taking my science advice from scientists.
Sunday 27 October 2013
Sunday 12 May 2013
Sweet poison
It looks like David Gillespie has a new best seller. I was just in my local bookshop, and there was a huge stack of the new Sweet Poison Quit Plan Cookbook. In it, you can several dozen recipes, mostly for baking and desserts, that will help us "enjoy delicious sugar-free baking". The only problem? The recipes are actually full of sugar. Sure, there is no table sugar (sucrose), but half a cup of dextrose (otherwise known as glucose) will still spike your blood sugar.
The new cookbook is a follow-up to Gillespie's "Sweet Poison" and "Sweet Poison Quit Plan", in which he explains that exercise won't make you thin, and cutting out fat won't make you thin, both of which are reasonable claims. He goes on to point out that an increas in sugar consumption parallels our obesity epidemic, also true, but that's when he departs form mainstream nutrition advice... He argues that the problems with sugar are all to do with fructose, which hooks up with glucose to form a sucrose (table sugar) molecule. Definately, fructose is something we could all afford to cut down on, and Gillespie has done us a service in helping people decrease the sugar in thier diets. But the idea that glucose is a completely safe alternative, and we should limit our fruit intake but then have glucose brownies? Seems unlikely. In fact, a recent meta-analysis looked at the effect of fructose on obesity and found that as long as the participants ate the same amount of energy, fructose was not associated with weight gain. It did cause weight gain when it was added to the diet, but that's exactly what you expect if you eat more energy. Of course, that meta-analysis was only able to include data on a few hundred people, and it would be great to see more trials on the health effects of different sugars. But for now, cutting out fructose in preference to glucose is really only supported by a few rat studies.
Wednesday 3 April 2013
Nutritional labels count
Putting nutritional information on food is a great way to help people make healthier choices. New legislation in the US means that chain restuarants are now obliged to provide this informationl, and many have done it voluntarily already. But the next question is: how accurate is the information? It's a question I started asking myself 10 years ago, when I was working on the drive-through at McDonalds, and idly flicking through the nutrition pamphlet. During a lull in traffic, I divided the amount of fat in a box if fries by the total mass of the fries... and found that large fries were listed as having a different percentage of fat than small fries. Um, what? Perhaps that one was a typo, and McD's information looks pretty good now, but there are loads of other ways in which labels can mislead us. For example, I was delighted to find that a pot of my favourite yoghurt was a light 500kJ (120Cal), until I realised that that was per serving, and the pot contained two servings. Seriously? Who would pull the foil off, eat the top part with the crunchy toppings, and save the bottom half for later?
This video shows how bad the labelling accuracy was in a random sample of US food, and asks the question... who is checking up on the labellers? In some cases it's high school chemistry students, for example the 14-year-olds who showed that Ribena didn't contain the vitamin C it claimed. If you test a sample and find that the labelling is wrong, you can make a complaint about false advertising, but it seems that other than that there is little guarantee on the quality of information. Govornment funding for independent random testing is probably never going to emerge, but perhaps food manufacturers could be obliged to have their testing done by labs that are held to high standards, like they do in pharmaceutical industry. That kind of actual testing of food is not required, at least not in Australia and New Zealand, where manufacturers can just estimate their product's nutritional content using an online database of ingredients. Because this online calculator can't account for different seasons and batches of ingredients, it's not surprising that companies often get it wrong, and you can end up eating more than you bargained for. Because the numbers on the labels look so specific, with thier reassuring decimal points, it's tempting to think that you rely on them to calculate your daily 'food budget' down to each snack, but that probably isn't the case.
Nutritional information needs to be accurate, but it also needs to be intuitive. Educated consumers are already making use of the nutritional labels available on the back of packs in Australia, the US and other countries, but the next challenge is how to make that information super easy for less determined consumers. In the US, serving size is expressed in household measurements like tablespoons, which is supposed to be simpler than the grams used in the Australian standard (reference). But it means some serious mental arithmetic is required to figure out the healthier choice if two products, and if there's one thing most people don't want to do when they're hungry, it's serious mental arithmetic. Front-of-pack labelling has got a lot of support from researchers, but at the moment there are a lot of different ideas on how to make it simple. One novel study showed that the number of minutes you would have to walk to burn off some food was even more effective than the energy information. Let's hope we see more of this kind of research, because there's no point telling people to eat healthy if they can't actually identify healthy food.
This video shows how bad the labelling accuracy was in a random sample of US food, and asks the question... who is checking up on the labellers? In some cases it's high school chemistry students, for example the 14-year-olds who showed that Ribena didn't contain the vitamin C it claimed. If you test a sample and find that the labelling is wrong, you can make a complaint about false advertising, but it seems that other than that there is little guarantee on the quality of information. Govornment funding for independent random testing is probably never going to emerge, but perhaps food manufacturers could be obliged to have their testing done by labs that are held to high standards, like they do in pharmaceutical industry. That kind of actual testing of food is not required, at least not in Australia and New Zealand, where manufacturers can just estimate their product's nutritional content using an online database of ingredients. Because this online calculator can't account for different seasons and batches of ingredients, it's not surprising that companies often get it wrong, and you can end up eating more than you bargained for. Because the numbers on the labels look so specific, with thier reassuring decimal points, it's tempting to think that you rely on them to calculate your daily 'food budget' down to each snack, but that probably isn't the case.
Nutritional information needs to be accurate, but it also needs to be intuitive. Educated consumers are already making use of the nutritional labels available on the back of packs in Australia, the US and other countries, but the next challenge is how to make that information super easy for less determined consumers. In the US, serving size is expressed in household measurements like tablespoons, which is supposed to be simpler than the grams used in the Australian standard (reference). But it means some serious mental arithmetic is required to figure out the healthier choice if two products, and if there's one thing most people don't want to do when they're hungry, it's serious mental arithmetic. Front-of-pack labelling has got a lot of support from researchers, but at the moment there are a lot of different ideas on how to make it simple. One novel study showed that the number of minutes you would have to walk to burn off some food was even more effective than the energy information. Let's hope we see more of this kind of research, because there's no point telling people to eat healthy if they can't actually identify healthy food.
Monday 18 February 2013
The Heavy
Dealing with obesity in children is fraught with danger. Ignore the problem, and a kid has a pretty big chance of staying heavy, unhealthy and unhappy for thier whole life. But if you tackle the problem and put the kid on a diet, are you depriving them of essential childhood experiences? Are you setting them up for an unhealthy relationship with food?
As Dara-Lynn Weiss explains in her new book, 'The Heavy', parents of obese children can't win. Last year, she wrote an article for Vogue describing her successes and failures in helping her then 7 year old daughter lose weight. The article included frank descriptions of how she deprived her daughter, sometimes in public, of the calories she so badly wanted (but didn't need). It also revealed Weiss' own yo-yo dieting past, alongside glamorous photos of svelt mother and super cute almost-normal-weight daughter. Bloggers crucified Weiss for her parenting, impying that she was shallow and forcing her insecurities onto her daughter. But what the article missed, and what comes through in the book, is just how normal Weiss is, and how hard it is to be the perfect parent to a kid with a weight problem.
In response to the Vogue article, one blogger writes: "SO what should a mother say about a daughter’s weight? NOTHING". But saying nothing can't be the right path if a kid really is obese. Putting a kid on a diet may risk body image problems later on, but letting them continue to gain weight when they're already obese almost guarantees it. And what do you do when cutting junk food, encouraging active play and limiting couch time don't help? Cutting calories looked like the only way for Weiss and her daughter, but well-meaning outsiders continued to be shocked at such drastic changes. "It is normal to assume" says Weiss, "if your child is a healthy weight, that your family’s food and activity choices are responsible for that fact, and that if other families did as yours did, their kids would be healthy, too." But you can get fat and stay fat eating relatively healthy food, and Weiss' story emphasises that the gentle approaches of balance and moderation just aren't enough for some of us. She also tackles society's weird expectations for body image and health, where one should enjoy food but also not be fat but also not think too much about whether we are fat. Considering obesity is currently a bigger threat to glabal health than eating disorders, it's a dialogue we badly need to have.
As Dara-Lynn Weiss explains in her new book, 'The Heavy', parents of obese children can't win. Last year, she wrote an article for Vogue describing her successes and failures in helping her then 7 year old daughter lose weight. The article included frank descriptions of how she deprived her daughter, sometimes in public, of the calories she so badly wanted (but didn't need). It also revealed Weiss' own yo-yo dieting past, alongside glamorous photos of svelt mother and super cute almost-normal-weight daughter. Bloggers crucified Weiss for her parenting, impying that she was shallow and forcing her insecurities onto her daughter. But what the article missed, and what comes through in the book, is just how normal Weiss is, and how hard it is to be the perfect parent to a kid with a weight problem.
In response to the Vogue article, one blogger writes: "SO what should a mother say about a daughter’s weight? NOTHING". But saying nothing can't be the right path if a kid really is obese. Putting a kid on a diet may risk body image problems later on, but letting them continue to gain weight when they're already obese almost guarantees it. And what do you do when cutting junk food, encouraging active play and limiting couch time don't help? Cutting calories looked like the only way for Weiss and her daughter, but well-meaning outsiders continued to be shocked at such drastic changes. "It is normal to assume" says Weiss, "if your child is a healthy weight, that your family’s food and activity choices are responsible for that fact, and that if other families did as yours did, their kids would be healthy, too." But you can get fat and stay fat eating relatively healthy food, and Weiss' story emphasises that the gentle approaches of balance and moderation just aren't enough for some of us. She also tackles society's weird expectations for body image and health, where one should enjoy food but also not be fat but also not think too much about whether we are fat. Considering obesity is currently a bigger threat to glabal health than eating disorders, it's a dialogue we badly need to have.
A whole new way of forking
So you're tracking your heartrate with a chest-strap monitor, you're logging your energy intake with an online food diary, you wear a pedometer to work... what more is there for the metric-loving dieter? Well, there's a bit of buzz building about a fork that will track your mouthfuls, perhaps acting as a pedometer for your meals. It's an interesting idea. Because it tracks the rate you take forkfuls, and can vibrate if you go too fast, the Hapifork provides excellent feedback to fast eaters, and I think it has a real chance of improving thier habits. For those of us who eat mindlessly or just eat stuff we shouldn't, the fork has yet to prove that it's worth $99. When it comes to weightloss, persuading people to buy more stuff has never been hard. When this product goes on the market later in 2013 I look forward to hearing if it really makes a difference, or if it's just another gadget.
Tuesday 1 January 2013
Softdrinks: how bad are they?
Health food campaigns when I was growing up were all about avoiding fatty foods. Not much was said about sugar, which allowed advertisers to imply that fat free, high sugar products were healthy. Now, people are a lot more suspicious of sugar. This comes partly from the low-carb diet movement, and partly from research into the causes of obesity and type II diabetes.
There's still a lot of debate about which macro-nutrients we should be consuming more of. If the goal is to feel full with minimum kilojoules, then there's conflicting evidence on whether protein, complex carbohydrate or fat will give you the best bang for your buck. But everyone seems to agree that sugar is one to avoid. And if you want to reduce sugar, then the first thing to cut out is sugary beverages. After all, marshmallows may be 66% sugar, but at least that comes along with 2.5% protein and 14% complex carbs. Soft drinks are the definition of empty kilojoules.
But are kilojoules from sugar really any worse than the energy you get from, say, white bread? Starch is quickly broken down to glucose, while sucrose is broken down to glucose and fructose. Perhaps that fructose molecule is the cause of all the havoc. This is a complicated topic, and one that I'll come back to, but what is becoming very clear indeed is that soft drink consumption is not only associated with, but also causes weight gain.
In spite of all this though, we drink huge amounts of them. A recent Australian report suggested that more than half of 19-24 year-olds consume more than half a liter of soft drink per day. For some groups, soft drink is accounting for 10% of daily energy consumption, and there's evidence that this is not adjusted for by eating less of other things. Interestingly, after the age of 12, males consistently consumed more soft drink than females. This goes against the stereotype that women are the ones with the sweet tooth.
But are kilojoules from sugar really any worse than the energy you get from, say, white bread? Starch is quickly broken down to glucose, while sucrose is broken down to glucose and fructose. Perhaps that fructose molecule is the cause of all the havoc. This is a complicated topic, and one that I'll come back to, but what is becoming very clear indeed is that soft drink consumption is not only associated with, but also causes weight gain.
In spite of all this though, we drink huge amounts of them. A recent Australian report suggested that more than half of 19-24 year-olds consume more than half a liter of soft drink per day. For some groups, soft drink is accounting for 10% of daily energy consumption, and there's evidence that this is not adjusted for by eating less of other things. Interestingly, after the age of 12, males consistently consumed more soft drink than females. This goes against the stereotype that women are the ones with the sweet tooth.
Friday 9 November 2012
Neuroscience will save us... eventually
Losing weight is simple. You just need to make sure you eat less than you burn. But then... why is anyone fat? The answer lies in neuroscience. Our brains are hardwired to seek energy-dense food and for most people, this basic drive can't really be overcome. The goal of this blog is to look into the research and begin to understand why our brains are so hungry, and what we can do about it.
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