Bad Appetite

Think French, stay thin.

Susan Carnell, Ph.D. — Sun, 22 Nov 2009 16:41:58 +0000

Brigitte Bardot. Juliette Binoche. Anna Karina. What is it about French actresses that makes them so attractive? Well the accent certainly helps - it's hard not to be drawn to someone who sounds like they're reciting poetry even when they're ordering an egg sandwich.

But of course they also tend to be gorgeous, leggy, toned and slim.

Nothing exclusively gallic about that, obviously - those traits tend to cluster in movie stars whatever their birthplace. But there's also a common belief that, despite a predilection for cheese, steak frites, and pain au chocolat, regular French women don't get fat.

Why should this be so? One popular theory is that the French way of eating means they only eat small amounts of these fatty foods.

For example, traditionally, French people take a long lunch, and food is savored rather than bolted. Researchers have known for a long time that eating slowly is associated with less intake and lower weight, and a recent experiment showed this is probably because it gives your gut more time to send your brain chemical messages telling you to put down the pâté.

Somewhat counter-intuitively, French gourmet classics may also encourage sensible portion sizes. For example, camembert and entrecôte are high in protein and fat, and both of these have been shown to make people feel fuller than an equal number of calories from carbohydrate.

Eating well-prepared, delicious foods could also give foodies a bigger reward hit than sugary junk, with the result of making them feel happier and stop stuffing themselves sooner.

Or maybe it's because French women have different attitudes.

According to best-selling author Mirielle Guiliano, they don't openly obsess about weight and shape, and generally eat for pleasure rather than health or weight control.

But there does seem to be an implicit acceptance that being slim is desirable, and it's much harder to find French support for the implicit American attitude that controlling intake is always painful, and the more laudable notion that everyone should have high body-esteem regardless of their size.

French women may also pass slender attitudes on to their children - in a cross-cultural survey US parents were more likely to give their children food to reward or comfort them, even when they were not hungry, whereas French parents were more likely to monitor their child's food intake to keep an eye on their weight.

So should we all hot-tail it to France if we want to stay slim and healthy?

In terms of heart health the answer might be yes. The so-called French paradox (the mystery of why fatty French diets don't cause heart attacks) continues to perplex experts, with France resolutely boasting among the lowest cardiovascular disease deaths in the world. Some of that's down to the French health system, of course, but lifestyle definitely contributes.

Weight-wise, however, the answer might not be as clear. Although America is still the fattest nation, with about 32% of adults obese and an additional 34% overweight, the latest tallies suggest that the onslaught of le Big Mac has meant that France is also tubbier than it used to be: currently around 13% of French adults are obese and nearly 31% overweight.

And although heart disease is low, high rates of smoking and alcohol consumption paired with low intake of fruits and vegetables make the cancer statistics less happy reading.

(In fact, since spoilsport researchers showed grape juice protects the heart equally as well as red wine we can't even use the heart disease stats as an excuse to drink copious amounts of Bordeaux).

So perhaps the best plan of action is to borrow from the French lifestyle the aspects we like the most, and hope we end up as lithe, confident and sophisticated as the stereotypical French female that we hold in our collective imagination.

Personally, I'll be shunning the elaborate beauty regime and sickly-sweet patisserie in favor of long vacations, free health care and a nice stinky slice of brie.

Bon appétit!

Forbidden fruit

Susan Carnell, Ph.D. — Sat, 31 Oct 2009 22:00:58 +0000

Got kids? Live near kids? Used to be one?

If you answered yes to any of those questions Halloween will not have passed you by unnoticed. The 31st October is fun for everyone, of course, but kids definitely get the best deal. Parties. Superhero costumes. And a once-a-year opportunity to extort unlimited supplies of candy from their neighbors and play tricks on those who don't cough up.

Parents certainly come to expect a few upset tummies after the festivities - even a chocolate-loving 3-year old starts to feel a little peaky after his seventeenth Reese's peanut butter cup. But what are the longer term effects of teaching kids that candy bars and salty fat-filled snacks are naughty objects that are only allowed to be consumed freely on certain days of the year?

Some psychology research suggests restricting junk food may have the paradoxical effect of making kids like it even more than they already do.

In one oft-cited study experimenters picked two equally-liked snackfoods - let's call them Eyeballs and Fingers, in keeping with the Halloween theme. They sat a bunch of kids round a table laden with big bowls of Eyeballs and told them they could eat as many as they wanted. Meanwhile the Fingers were presented on the same table in a transparent box and children were forbidden to eat them.

In a later part of the study when children were given free access to both it was clear which the kids had learned to prefer - the (previously forbidden) Fingers disappeared hand over fist while the (previously available) Eyeballs sat relatively untouched.

Of course, this was just a short-term experiment - for all we know when the kids next saw Eyeballs and Fingers they wolfed both of them down without discrimination. But other studies have also shown that kids with parents who adopt a strict policy of restricting junk eat more of it when confronted with unlimited piles and given permission to cram in as much as they'd like.

So does this mean that restriction and keeping some foods as treats are doomed enterprises? Should we give kids free rein to eat what they like and hope they end up eating healthy of their own accord?

The answer is probably No. Children need guidance to make sensible choices in today's junk-filled environment. But other research suggests that there are better ways to do it than rigid limitations.

For example, one study found that ‘covert' control strategies - like taking your kids to restaurants with healthy choices, or avoiding keeping junk in the house - were linked with less intake of unhealthy snacks in kids. And another found that mothers who used an ‘authoritative feeding style' - supporting kids to eat healthily without ramming it down their throats - had children with healthier diets.

Where does that leave parents regarding challenges like Halloween or Easter, when every child expects to be spoilt with sweets?

Resistance is probably futile and may make matters worse to some degree. So it's probably best to be flexible and allow a little junk. But festivals are also a great opportunity to sneak in some nutrients and sew the seeds of a few new healthy preferences (for fun Halloween ideas beyond the candied apple take a look here).

After all, most little boys are pretty skeptical when you ask them to try a lychee for the first time. But have you tried telling one it's a monster's eyeball or a horntailed dragon's egg? I guarantee you they'll be flying off the plates in no time.

Hey stupid! How your eating habits can make you dumb.

Susan Carnell, Ph.D. — Sat, 10 Oct 2009 23:06:52 +0000

Can't remember your phone number? Defeated by a tax and tip calculation? Simple Sudoku got you scratching your head?

Don't worry - we all feel a little stupid sometimes. Maybe you haven't been getting enough sleep. Maybe you had one too many glasses of cabernet last night. Maybe the sudoku was just extra hard today.

Then again, maybe all that crap you eat is addling your brain.

It's long been thought that nutrition can influence your mental faculties. The idea has given rise to hundreds of popular books and articles, and it's undeniable that energy deprivation or vitamin and mineral deficiencies can screw us up - if we don't eat certain things we need it can impair our physical and mental functioning.

However, more exciting to an obesity researcher like me is evidence that things we do eat - and often to excess - may also influence how we think.

For example, rats who were fed a high-fat diet for just ten days in a recent study not only got more exhausted when exercising on a treadmill - but also more forgetful and less successful at hunting down rewards in a standard maze puzzle.

And it gets worse. Not only might junk food make you a dim-wit, but if you eat enough of it to become obese it could permanently affect your brain.

In a study of elderly obese and lean humans, the obese ones showed greater shrinkage in frontal, temporal and subcortical areas, compared with their leaner counterparts. Some of this may have been due to the obese people having diabetes - which is already known to affect the brain - but the atrophy was still linked to weight even after factoring that out.

Sadly, the subjects in this study didn't do any tests or sudokus, so we don't know whether those with a shriveled hippocampus were any more dense than those without. But it's probably fair to say that - when it comes to brains - bigger is generally better.

All pretty scary, huh? Probably best to stick to salads and keep your weight down?

Not necessarily. Scoffing junk and getting fat might be mental murder, but nibbling lettuce leaves in an effort to slim down could make you feel even more foolish.

Anorexic patients perform worse at tasks designed to test ‘set-shifting,' a type of flexible thinking involving the prefrontal cortex of the brain (although this could well be a cause rather than a result of the disorder).

And women who say they're dieting to lose weight show slower reaction times, and poorer recall in word memory tests. This might be because they lack dietary fuel to get their brains going, but it's also because thinking about all the food you're not allowing yourself to eat is thoroughly distracting and a drain on your mental energy.

As with most other things in life, the wealth of evidence on the diet-cleverness problem seems to suggest that balance is best.

In fact, achieving optimum body weight and brain function is really very simple, if you think about it: Don't starve yourself so much that fantasies of french fries overwhelm your powers of reasoning - but don't stuff yourself so much that your mind goes into meltdown.

(And if you believed what I just said about weight control being easy, then you really must be stupid...)

Scare yourself skinny.

Susan Carnell, Ph.D. — Wed, 23 Sep 2009 22:40:36 +0000

Remember when cigarette packets were just pretty little boxes with fancy lettering?

Nope, neither do I. For as long as I can recall they've been covered with scary health warnings. And if you light up in the UK or Canada you might even get treated to a graphic image of a diseased lung or some rotting teeth.

As a non-smoker who never worked out how to inhale properly those packets are certainly enough to put me off trying again.

And the deterrent works on others too: nearly two thirds of Canadians in a telephone survey said the warnings made them think about health risks, cut down on ciggies, or increase their motivation to quit.

But can the shock-and-awe approach also get people to improve their eating habits?

Officials at the New York City Health Department say yes. As part of a new campaign to reduce intake of sugary drinks, subway cars will be plastered with posters cautioning riders against ‘pouring on the pounds.' And the exhortation will be bolstered by an arresting visual aid - gristly yellow globs of human fat tissue tumbling forth from a bottle of soda.

(Meanwhile others are also trying to harness fat's potent yuckiness. Visit www.mypetfat.com to purchase your very own five-pound model of human body fat - then put it on top of the Ben and Jerry's and see how hungry you feel when you catch an eyeful during your next attack of the munchies.)

On balance, research does seem to suggest that scary warnings can work.

For example, one recent review paper found that, although people could be successfully persuaded to reduce salt intake or eat more fruits by telling them about the benefits that would be gained, emphasizing the bad consequences of failure to do those things worked equally as well.

And as for the gross-out element, there's every reason to think that pairing an unhealthy item with an innately yucky image should make the attached health message more powerful.

Pictures can speak a thousand words (especially helpful if literacy is a problem), while snappy, visually compelling messages can be highly persuasive. You never know - the poster could even condition an automatic disgust reaction to the sight of a raspberry Snapple.

Of course this is all contingent on commuters paying attention to the ad.

Maybe the only reason the cigarette warnings work is because they sit directly on the packet, impossible to ignore. In contrast, if people find the subway posters repulsive they can always look away. And if they find the fat connection too horrific they could even refuse to acknowledge it and go hunting for a nice sugar fix to cheer them up - a kind of fat-promoting boomerang effect.

The truth is that the posters will probably affect each person differently. After all, while some of us prefer tough love and straight talking, others find pills easier to swallow if they're washed down with something sweet.

Soda, anyone?

Out of control? How holding back can make you fat.

Susan Carnell, Ph.D. — Tue, 11 Aug 2009 21:14:35 +0000

Ever been out for dinner with a friend and watched in wonder as she ordered the tuna salad with no dressing then turned away the dessert trolley to save on calories? Your buddy is a ‘restrained eater'. But does it actually make her thin and happy?

Back in the 1970s most psychologists would have resoundingly said ‘No.' Received wisdom was that if you banned yourself from eating Twinkies you'd only feel deprived and binge on Oreos later, eventually making you fat and miserable.

Subsequently they started to realize that often people only started limiting their diets when they were already overeating, overweight or dissatisfied with their bodies. The mere act of restraining wasn't enough to provoke disinhibited eating and excessive weight gain all by itself.

Now most eating researchers have moderated their opinions. They think that restraint has the potential to be counter-productive - but only if it's done in a rigid, inflexible fashion.

For example, if Ms Restrainer ordered a low calorie dinner and ate oatmeal for breakfast but joined her work colleagues in (sensible) portions of pizza and ice-cream at an unexpected free lunch, she's probably not about to become disinhibited and obese any time soon.

On the other hand, if she ate the salad for dinner, three scheduled strawberries for breakfast and a big plate of nothing at lunch-time, she may be at risk of counter-regulatory overeating, or could even have anorexic tendencies, requiring your understanding and support.

Of course people don't always restrict their eating because of the desire to be thin.

Maybe your mate has just been persuaded by the latest scientific evidence on how caloric restriction helps you stay healthy and live longer.

In a recent study, rhesus monkeys were fed 30% fewer calories than a matched control group who were fed an amount appropriate for their age and weight. Twenty years later they were three times less likely to have died than those fed the normal diet. They also had better glucose regulation and larger brains, especially in areas involved in movement and memory.

Sounds good, yes?

But I know what you're thinking. Rigid control - whether it's motivated by concern for weight or longevity, and whether it makes you skinny, fat or somewhere inbetween - doesn't exactly sound like a recipe for happiness.

Imagine it. Whenever your friends offered you a slice of birthday cake you'd have to say no. If they invited you to a fancy restaurant you'd have to miss out or sit there nibbling miserably on the crudités. No more cheese plate. And even worse: No. More. Alcohol.

The fact is that no one wants to be that person. Nor do they want to hang out with someone who is that strict with themselves. Partly because it makes them feel bad about their own behavior, but also because a certain amount of impulsivity and abandon is attractive in people.

That said, it's undeniable that most people want to keep their weight in control as well as have a good time.

So next time you're out with your buddy and perusing the specials, take a good look and think about what will make you both happiest in the long run.

Maybe she was right about the naked nicoise all along. It might not push your personal taste buttons right away - but paired with a side order of flexible restraint it might turn out to be the most satisfying choice on the menu.

Til breadth do us part

Susan Carnell, Ph.D. — Sun, 19 Jul 2009 17:37:05 +0000

Last week I had an argument with a good friend of mine. He said if his girlfriend was getting fat and he felt less attracted to her, he'd let her know about it and encourage her to lose weight.

I was outraged. Tell a woman she's fat? Isn't it enough to be constantly bombarded with media images of skinny female perfection? Now we can't even expect our boyfriends to think we're unconditionally beautiful, belly and all?

When health psychologists try to change people's eating habits they talk about ‘stages of change.' They say you have to battle through six different phases before emerging, butterfly-like, new behaviors ingrained. Before you start even preparing to change something you have to progress through ‘precontemplation' (you don't care what you eat), and ‘contemplation' (you want to improve but you can't be bothered).

It's likely (but not inevitable) that if your girlfriend's getting fat she's already in the contemplation phase. So it's possible that your devastating comment could act as a critical impetus to end her gluttonous ways.

But we also know that trying to scare people into changing well-established, rewarding behaviors doesn't always work. You can tell British women binge drinking is bad news - but if they like the feeling they get from a few shots of vodka they aren't going to give up the screwdrivers.

In the case of eating, scary messages could even backfire. Feeling depressed and unattractive can trigger overeating in those with a tendency to binge. And social support is critical for a diet to work - if your girlfriend sees you as an enemy instead of an ally you won't be helping her at all.

I'm not saying it's never right to address the weight issue head on. But there are more subtle methods it might be worth trying first.

Instead of saying you find your partner less attractive you could both make an effort to eat more healthily when you're together.

People also respond well to ‘gain-framed' messages targeted at their personal needs, so you could risk saying something like, "Obviously I think you're totally hot as you are. But I feel like if you lost a few pounds you'd be more confident and happy, and I'd love to see you appreciate yourself more. Please don't hit me."

And what if she doesn't appreciate your opinion, no matter how well-intentioned or delicately put?

I wouldn't count on being allowed back into the marital bed for a good few weeks - at least not until you've eaten your words.

Feeding your feelings? Why you comfort eat and how to stop.

Susan Carnell, Ph.D. — Mon, 25 May 2009 21:36:42 +0000

Just had a pay cut? Spurned by your lover? Can't get over the fact that the little guy won American Idol?

When the initial gut-wrenching surge of anxiety subsides you may find yourself reaching for the chocolate brownies. This is because when something stresses you out it triggers a two stage reaction.

First, the fight or flight response: your heart speeds up, your muscles tense, your digestive system shuts down - all so you can focus on attacking your stress object or running away. (If someone offered you a brownie at this point you'd probably punch them in the face.)

But next comes a slower response: your adrenal gland unleashes a nifty little hormone called cortisol. Cortisol helps you use energy more efficiently by telling your body to start making glucose and burning up fat.

Unfortunately, it may also tell you to get to the nearest vending machine and load up on candy.

How do we know this? Well it's definitely true for rats. When you stress them out by pinching their tails or injecting cortisol they drink more condensed milk or sucrose.

Humans are harder to study - they won't let you pinch them and they might not drink condensed milk for you even if they want to. But in one study, women who released the most cortisol during an onslaught of stressful tasks ate more snacks than other women who only released a small amount.

Interestingly enough, the cortisol effect only works with tasty, high fat foods. Humans picked chocolate bars rather than rice cakes in the stressful task study. Rats won't eat more boring old lab chow however much you bug them. And back in the real world, people who say they're stressed in general have a diet that's higher in fat.

The diet difference could partly be because life demands force the stressed masses to rely on more high-calorie convenience foods. But it also makes good evolutionary sense to stockpile calories in difficult times - you never know when some extra energy might come in handy.

Of course comfort-eating needn't necessarily be the bad thing it's made out to be. As my unremittingly optimistic grandmother always says - a little bit of what you fancy does you good. And one study in Taiwan found that children who ate junk food were fatter, but happier. Isn't it worth gaining a few pounds to feel a little more cheerful all round?

If eating fries and fritters was the only way to be happy I would say, categorically, yes. But new research suggests that cortisol actually increases appetite by acting more generally on emotional brain areas, with the effect of increasing the desirability of all pleasurable activities - not just stuffing one's face with food.

The message? Eating might be the way you usually find your solace, but it never hurts to try something different instead.

Remember that the next time someone tries to pinch your tail.

Does my brain look fat in this?

Susan Carnell, Ph.D. — Sun, 12 Apr 2009 22:03:18 +0000

Sweet tooth. Greedy guts. Hungry eyes. Lazy bones. We blame every part of the body for making us fat, but there's one vital organ we sometimes forget to mention: the brain.

Maybe we don't say it because it's so obvious. The brain controls all complex behaviors, and that includes planning what to get from a fast-food restaurant, or deciding when to put down your spoon and step away from the ice-cream tub.

What's interesting is that if you're obese, your brain looks different even before you start making those decisions. Not so much in terms of structure or volume - Homer Simpson's brain size is clearly nothing to do with his ample weight - but in terms of responses to stimuli.

In one study, researchers showed lean and obese females pictures of food and scanned their brains. When the obese women were shown high calorie foods, they showed greater activity in the orbitofrontal cortex and striatum - areas associated with anticipating reward.

(And if simple pictures can trigger excitement just think about what the real world can do, with its onslaught of food smells and snack carts and fast-food ads.)

Of course the brain's involvement doesn't end there.

In another study people were given food rather than just looking at pictures of it. This time obese participants showed less activation in the striatum. This suggests that - although certain foods inspire high hopes for reward - when consumed they actually produce less of a thrill than expected. This creates the urge to eat greater amounts, and seek out tasty calorie-packed morsels which provide a bigger hit.

In truth, it's a very new area of science - you have to be pretty brainy to work out what on earth's going on up there.

But what you definitely can't tell from these particular studies is whether obese adults are really born with fat brains that compel them to overeat. It's equally likely that heavier people learn to eat in certain ways and this is what makes them gain weight and shows up in the fMRI scan. The state of being fat could even actively change the way your mind works.

What can you do if you happen to have a fat brain?

The answer is probably to avoid the triggers that set your food neurons firing. Successful dieters show greater activity in brain areas involved in inhibiting responses - so you can always try to reprogram yourself. And if all else fails there's a sure way to lose three pounds, although I wouldn't recommend it.

Total lobotomy, anyone?

Is obesity contagious?

Susan Carnell, Ph.D. — Sun, 15 Mar 2009 20:04:57 +0000

Ever heard the phrase ‘obesity epidemic' and thought it seemed a bit peculiar? Obesity's just about eating too much and exercising too little isn't it? It's hardly the bubonic plague or the Spanish flu.

Wrong, says Nikhil Dhurandhar from the Pennington Biomedical Research Center. For nearly 20 years he's been amassing evidence that an influenza-like virus called Ad-36 may be penetrating our systems and making us pile on the pounds.

But his argument may not be nearly as robust as the nation's expanding waistline.

It's true that if you inject Ad-36 into your average lab rat it makes his belly flabby. It looks like this happens by recruiting more cells to get busy turning energy into fat. Dhurandhar's also shown that very obese people attending obesity treatment are more likely to be infected than skinny ones out in the community.

But rats aren't people. And people attending obesity treatment are hardly typical of the population at large - they often have more severe cases linked with a host of health problems and lifestyle differences.

For a really thorough and critical review of all the evidence, you can take a look here. But it's probably fair to say the human obesity virus theory has yet to really...catch on.

Of course that's not to say that fatness isn't infectious in some other way.

Using weight and height data gathered from over 12,000 interconnected individuals, a team from Harvard looked at the spread of obesity through a social network. (I am still waiting for someone to replicate this experiment on Facebook or Twitter. We just need everyone to weigh themselves every week and own up to it in their updates...)

Chubby people evidently stuck together - there were clusters of obesity all over the network, extending through to people up to 3 degrees of separation from the index obese person. But heavier individuals also made their mates gain weight - a person was 57% more likely to become obese if he had a friend who also tipped the balance over the same time period.

Why? Well friends hang out together at the same places and do the same kind of things. Maybe it's no fun to get a salad when your companion just ordered a deep-fried grilled cheese sandwich. If your buddy's having a beer wouldn't it be rude to abstain? And who wants to walk to work when your boyfriend's driving and could give you a ride?

That said, catching your friends' habits needn't be a bad thing if they're better than your own. In my last job - also in obesity research - anyone who came in on the heavy side left feeling lighter. It was just impossible to enjoy a lunchtime burger and fries in the midst of all those celery sticks, fruit salads and wholegrain baps.

What should we take from all of this? First off, we probably don't need to start worrying about being doused in fatness germs the next time a large person sneezes in our vicinity. Secondly, although there's evidence that unhealthy habits can spread between people, we should take comfort in the knowledge that there's absolutely no reason why healthy ones shouldn't rub off too.

Maybe contagion needn't be such a bad thing after all.

Want to seduce your valentine? Whittle down your waistline.

Susan Carnell, Ph.D. — Sat, 14 Feb 2009 20:34:23 +0000

I just don't buy the myth that fat people get to have less sex than skinny people - at least not the ones with good old, regular, common-or-garden fat.

Nearly two thirds of us are overweight or obese yet we seem to be finding mates and reproducing somehow. We can no longer tell who's unhealthily fat, making conscious prejudice a challenge. And people claim that men prefer to date skinny - or at least normal weight - but what if they're not so sleek and slender themselves? We're genuinely drawn to people who form a physical attractiveness match (and I'm told that a voluptuous hourglass figure more than makes up for a little fleshy overspill).

What does seem to be true is that if you're very overweight, losing some pounds can significantly improve the quality of your sex life. After gastric bypass - a surgery which decreases your stomach size and reroutes your gut - obese men experience a rise in sexual desire and an increase in sexual performance. This is partly due to hormonal changes - fat is an active organ and if you remove it you stop it pumping out chemicals which mess with sex steroids like testosterone. But losing weight also has psychological effects: a hit of confidence and self-esteem can really get your juices flowing.

Sadly, shedding your excess weight doesn't guarantee your ticket to sexual bliss. Obesity surgery is not a cure-all and some patients feel disappointed. The fat disappears but often the skin around it doesn't, leaving less-than-attractive flaps. The problems of life still remain, and can no longer be blamed on weight. And successful surgery can even break up marriages, by changing relationship dynamics and opening eyes.

Of course if you want to sharpen up your love life you don't have to go under the surgeon's knife. Losing just 10% of your body weight is enough to improve physical health and give yourself a feel-good boost. Research shows that despite the emaciated look of several infamous fashion-savvy starlets, real women are too smart to aspire to be anywhere near that skinny. Keeping a little chubbiness round the cheekbones can actually help you look healthy and young. And if you're really big don't think you have to shrink to half your size: 56% of gastric bypass patients in one study reported improvements in their sexual relationships even when they were still obese post-operation.

The message for Psychology Today's female readership? Losing a bit of excess fleshiness is great for your sex life, especially if it makes you feel self-confident and happy. But when you chuck out the Cheetos and stop super-sizing your fries - don't forget to keep an eye on your sexual partner's portions too.

Happy Valentine's Day everybody.