Search This Blog

19 March 2010

Obesity: The killer combination of salt, fat and sugar

For years I wondered why I was fat. I lost weight, gained it back, and lost it again – over and over and over. I owned suits in every size. As a former commissioner of the FDA (the US Food and Drug Administration), surely I should have the answer to my problems. Yet food held remarkable sway over my behaviour.

The latest science seemed to suggest being overweight was my destiny. I was fat because my body's "thermostat" was set high. If I lost weight, my body would try to get it back, slowing down my metabolism till I returned to my predetermined set point.

But this theory didn't explain why so many people, in the US and UK in particular, were getting significantly fatter. For thousands of years, human body weight had stayed remarkably stable. Millions of calories passed through our bodies, yet with rare exceptions our weight neither rose nor fell. A perfect biological system seemed to be at work. Then, in the 80s, something changed.

Three decades ago, fewer than one Briton in 10 was obese. One in four is today. It is projected that by 2050, Britain could be a "mainly obese society". Similar, and even more pronounced, changes were taking place in the US, where researchers found that not only were Americans entering their adult years at a significantly higher weight but, while on average everyone was getting heavier, the heaviest people were gaining disproportionately more weight than others. The spread between those at the upper end of the weight curve and those at the lower end was widening. Overweight people were becoming more overweight.

What had happened to add so many millions of pounds to so many millions of people? Certainly food had become more readily available, with larger portion sizes, more chain restaurants and a culture that promotes out-of-home eating. But having food available doesn't mean we have to eat it. What has been driving us to overeat?

It is certainly not a want born of fear of food shortages. Nor is it a want rooted in hunger or the love of exceptional food. We know, too, that overeating is not the sole province of those who are overweight. Even people who remain slim often feel embattled by their drive for food. It takes serious restraint to resist an almost overpowering urge to eat. Yet many, including doctors and healthcare professionals, still think that weight gainers merely lack willpower, or perhaps self-esteem. Few have recognised the distinctive pattern of overeating that has become widespread in the population. No one has seen loss of control as its most defining characteristic.

"Higher sugar, fat and salt make you want to eat more." I had read this in scientific literature, and heard it in conversations with neuroscientists and psychologists. But here was a leading food designer, a Henry Ford of mass-produced food, revealing how his industry operates. To protect his business, he did not want to be identified, but he was remarkably candid, explaining how the food industry creates dishes to hit what he called the "three points of the compass".

Sugar, fat and salt make a food compelling. They stimulate neurons, cells that trigger the brain's reward system and release dopamine, a chemical that motivates our behaviour and makes us want to eat more. Many of us have what's called a "bliss point", at which we get the greatest pleasure from sugar, fat or salt. Combined in the right way, they make a product indulgent, high in "hedonic value".

During the past two decades, there has been an explosion in our ability to access and afford what scientists call highly "palatable" foods. By palatability, they don't just mean it tastes good: they are referring primarily to its capacity to stimulate the appetite. Restaurants sit at the epicentre of this explosion, along with an ever-expanding range of dishes that hit these three compass points. Sugar, fat and salt are either loaded into a core ingredient (such as meat, vegetables, potato or bread), layered on top of it, or both. Deep-fried tortilla chips are an example of loading – the fat is contained in the chip itself. When it is smothered in cheese, sour cream and sauce, that's layering.

It is not just that fast food chains serve food with more fat, sugar and salt, or that intensive processing virtually eliminates our need to chew before swallowing, or that snacks are now available at any time. It is the combination of all that, and more.

Take Kentucky Fried Chicken. My source called it "a premier example" of putting more fat on our plate. KFC's approach to battering its food results in "an optimised fat pick-up system". With its flour, salt, MSG, maltodextrin, sugar, corn syrup and spice, the fried coating imparts flavour that touches on all three points of the compass while giving the consumer the perception of a bargain – a big plate of food at a good price.

Initially, KFC meals were built around a whole chicken, with a pick-up surface that contained "an enormous amount of breading, crispiness and brownness on the surface. That makes the chicken look like more and gives it this wonderful oily flavour." Over time, the company began to realise there was less meat in a chicken nugget compared with a whole chicken, and a greater percentage of fried batter. But the real breakthrough was popcorn chicken. "The smaller the piece of meat, the greater the percentage of fat pick-up," said the food designer. "Now, we have lots of pieces of a cheaper part of the chicken." The product has been "optimised on every dimension", with the fat, sugar and salt combining with the perception of good value virtually to guarantee consumer appeal.

He walked me through some offerings at other popular food chains. Burger King's Whopper touched on the three points of the compass – then was altered for further effect. In its first, stripped-down form, the burger was explosively rich in fat, sugar and salt. Then the chain began adding more beef, extra cheese or a layer of bacon. McDonald's broke new ground in another way – by making food available on a whim. "The great growth has been the snacking occasion. You get hungry, you want something, your mind pushes off the reality of what you ought to eat, and you end up picking up a hamburger and a giant soda or french fries."

Next they introduced a high-fat, high-salt morning meal. "They took what they learned from the core lunch and dinner menu, and applied it to breakfast. The sausage McMuffin and the egg McMuffin are stand-ins for the hamburger. In effect, you are eating a morning hamburger."

This kind of food disappears down our throats so quickly after the first bite that it readily overrides the body's signals that should tell us, "I'm full." The food designer offered coleslaw as an example. When its ingredients are chopped roughly, it requires time and energy to chew. But when cabbage and carrots are softened in a high-fat dressing, coleslaw ceases to be "something with a lot of innate ability to satisfy".

This isn't to say that the food industry wants us to stop chewing altogether. It knows we want to eat a doughnut, not drink it. "The key is to create foods with just enough chew – but not too much. When you're eating these things, you've had 500, 600, 800, 900 calories before you know it." Foods that slip down don't leave us with a sense of being well fed. In making food disappear so swiftly, fat and sugar only leave us wanting more.

According to food consultant Gail Vance Civille, of management consultants Sensory Spectrum, fat is crucial to this process of lubrication, ensuring that a product melts in the mouth. In the past, she says, Americans typically chewed food up to 25 times before it was swallowed; now the average American chews 10 times. "If I have fat in there, I just chew it up and whoosh! Away it goes," she says. "You have a 'quick getaway', a quick melt."

The Snickers bar, Civille says, is "extraordinarily well engineered". Unlike many products whose nuts become annoyingly lodged between your teeth, the genius of Snickers is that as we chew, the sugar dissolves, the fat melts and the caramel picks up the peanut pieces, so the entire candy is carried out of the mouth at the same time. "You're not getting a build-up of stuff in your mouth."

Kettle chips are another success story. Made of sugar-rich russet potatoes, they have a slightly bitter background note and brown irregularly, which gives them a complex flavour. High levels of fat generate easy mouth-melt, and surface variations add a level of interest beyond that found in mass-produced chips. Heightened complexity is the key to modern food design.

Not so many decades ago, a single flavour of ice-cream was a special treat. Our options ran to vanilla, chocolate and strawberry – and when we could buy all three in a single carton, we saw that as a great innovation. Now ice-cream has countless flavours and varieties; it comes mixed with M&M's or topped with caramel sauce.

When layers of complexity are built into food, the effect becomes more powerful. Sweetness alone does not account for the full impact of a fizzy drink – its temperature and tingle, resulting from the stimulation of the trigeminal nerve by carbonation and acid, are essential contributors as well.

"The complexity of the stimulus increases its association to a reward," says Gaetano Di Chiara, an expert in neuroscience and pharmacology at the University of Cagliari in Italy. Elements of that complexity include tastes that are familiar and well liked, especially if not always readily available, and the learning associated with having had a pleasurable experience with the same food in the past.

Take a bowl of M&M's. If I've eaten them in the past, I'm stimulated by the sight of them, because I know they'll be rewarding. I eat one, and experience that reward. The visual cue gains power and stimulates the urge we call "wanting". The more potent and complex foods become, the greater the rewards they may offer. The excitement in the brain increases our desire for further stimulation.

In theory there's a limit to how much stimulation rewarding foods can generate. We are supposed to habituate – to neuroadapt. When Di Chiara gave animals a cheesy snack called Fonzies, the levels of dopamine in their brains increased. Over time, habituation set in, dopamine levels fell and the food lost its capacity to activate their behaviour.

But if the stimulus is powerful enough, novel enough or administered intermittently enough, the brain may not curb its dopamine response. Desire remains high. We see this with cocaine use, which does not result in habituation. Hyperpalatable foods alter the landscape of the brain in much the same way.

I asked Di Chiara to study what happens after an animal is repeatedly exposed to a high-sugar, high-fat chocolate drink. When he'd completed his experiment, he sent me an email with "Important results!!!!" in the subject line. He had shown that dopamine response did not diminish over time with the chocolate drink. There was no habituation.

Novelty also impedes habituation, and intermittency is another driver. Give an animal enough sugar-laden food, withdraw it for the right amount of time, then provide it again in sufficient quantities, and dopamine levels may not diminish.

There's still a lot we don't know about the relationship between the dopamine-driven motivational system and our behaviour in the presence of rewarding foods. But we do know that foods high in sugar, fat and salt are altering the biological circuitry of our brains. We have scientific techniques that demonstrate how these foods – and the cues associated with them – change the connections between the neural circuits and their response patterns.

Rewarding foods are rewiring our brains. As they do, we become more sensitive to the cues that lead us to anticipate the reward. In that circularity lies a trap: we can no longer control our responses to highly palatable foods because our brains have been changed by the foods we eat.

I wanted to know how much the industry understood about how the food we eat affects us; about what I have termed "conditioned hypereating" – "conditioned" because it becomes an automatic response to widely available food, "hyper" because the eating is excessive and hard to control. I turned to Joseph Stiglitz, a Nobel laureate in economics.

"Does the industry know that what it feeds us gets us to eat more?" I asked.

"The industry has jacked up what works for it," Stiglitz said. "The learning is evolutionary." Practical experience has been its guide – it does not need lab rats when it can try out its ideas on humans. Its decision-makers do not have to analyse human brain circuitry to discover what sells.

A venture capitalist who knows the business intimately cited Starbucks as a company that has recognised and responded brilliantly to a cultural need. The caffeine and sugar in the coffee, with their energising effects, are certainly part of the equation, but the chain also offers something much more primal. "It's about warm milk and a bottle," he says. "One of my colleagues said, 'If I could put a nipple on it, I'd be a multimillionaire'."

But it was thinking creatively about how to attract more consumers that led Starbucks to the Frappuccino, the venture capitalist told me. Although its stores were crowded early in the day, by afternoon "they were so empty you could roll a bowling ball through them". The creation of a rich, sweet and comforting milkshake-like concoction utterly transformed the business. A Starbucks Strawberries & Crème Frappuccino comes with whipped cream and 18 teaspoons of sugar: all in all, this "drink" contains more calories than a personal-size pepperoni pizza, and more sweetness than six scoops of ice-cream. By encouraging us to consider any occasion for food an opportunity for pleasure and reward, the industry invites us to indulge a lot more often.

Starbucks learned a basic lesson: make enticing food easily and constantly available, keep it novel, and people will keep coming back for more. With food available in almost any setting, "the number of cues, the number of opportunities" to eat have increased, while the barriers to consumption have fallen, says David Mela, senior scientist of weight management at the Unilever Health Institute. "The environmental stimulus has changed."

Of course, when food is offered to us, we're not obliged to eat it. When it's on the menu, we don't have to order it. But this takes more than willpower. As an individual, you can practise eating the food you want in a controlled way. As a society, we can identify the forces that drive overeating and find ways to diminish their power. That's what happened with the tobacco industry: attitudes to smoking shifted. Similar changes could be brought about in our attitudes to food – by making it mandatory for restaurants to list calorie counts on their menus; by clear labelling on food products; by monitoring food marketing. But until then few of us are immune to the ubiquitous presence of food, the incessant marketing and the cultural assumption that it's acceptable to eat anywhere, at any time.

Call it the "taco chip challenge" – the challenge of controlled eating in the face of constant food availability. "Forty years ago, you might face the social equivalent of that taco chip challenge once a month. Now you face it every single day," Mela said. "Every single day and every single place you go, those foods are there, those foods are cheap, those foods are readily available for you to engage in. There is constant, constant opportunity."

Calcium may help you live longer: study

NEW YORK (Reuters Health) - Getting a bit more calcium in your diet could help you live longer, new research suggests.

Swedish researchers found that men who consumed the most calcium in food were 25 percent less likely to die over the next decade than their peers who took in the least calcium from food. None of the men took calcium supplements.

The findings are in line with previous research linking higher calcium intake with lower mortality in both men and women, the researchers point out in a report in the American Journal of Epidemiology.

While many researchers have looked at calcium and magnesium intake and the risk of chronic disease, less is known about the association between consumption of these nutrients in food and mortality.

To investigate, Dr. Joanna Kaluza of the Karolinska Institutet in Stockholm and her colleagues looked at more than 23,000 Swedish men who were 45 to 79 years old at the study's outset and were followed for 10 years. All had reported on their diet at the beginning of the study. During follow-up, about 2,358 died.

The top calcium consumers had a 25 percent lower risk of dying from any cause and a 23 percent lower risk of dying from heart disease during follow-up relative to men that had the least amount of calcium in their diet. Calcium intake didn't significantly influence the risk of dying from cancer.

Men in the top third based on their calcium intake were getting nearly 2,000 milligrams a day, on average, compared to about 1,000 milligrams for men in the bottom third. The US Recommended Dietary Allowance (RDA) for calcium intake is 1,000 milligrams for men 19 to 50 years old and 1,200 milligrams for men 50 and over.

"Intake of calcium above that recommended daily may reduce all-cause mortality," Kaluza and her colleagues conclude.

Calcium could influence mortality risk in many ways, they note, for example by reducing blood pressure, cholesterol, or blood sugar levels. For the men in the study, the main sources of calcium in the diet were milk and milk products and cereal products.

How to Prevent Low-Back Pain

Back pain is very common. It affects about 8 out of 10 people. But there are many steps you can take to avoid it. One of the best things you can do to prevent back pain is to exercise regularly and keep your back and abdominal muscles strong.

A program of regular low-impact exercises such as walking, swimming, or riding a bike—mobile or stationary—will be beneficial. Yoga can also help stretch and strengthen muscles and improve posture. Ask your doctor for a list of exercises appropriate for your age and physical condition.

Here are some quick pointers to prevent back problems:

Always stretch before any strenuous physical activity.

Don’t slouch when standing or sitting. When standing, keep your weight balanced on your feet. Curvature of the spine puts stress on back muscles.

Sit in chairs or car seats with good lumbar support. Switch sitting positions often and periodically walk around or gently stretch muscles to relieve tension.

Don’t bend over without supporting your back. For example, don’t lean over a low sink without bracing yourself with your hand. Also, don’t reach and lift an object out of a car trunk; first slide the object to the edge of the trunk.

Wear comfortable, low-heeled shoes.

Sleep on your side to reduce any curve in your spine. Always sleep on a firm surface.

Don’t try to lift objects too heavy for you. Lift with your legs keeping your back straight. Keep the object close to your body. Do not twist when lifting.

Try to control your weight, especially weight around the waistline that taxes lower back muscles.

If you smoke, quit. Smoking reduces blood flow to the lower spine and causes the spinal discs to degenerate.

To keep your spine strong, as with all bones, you need to get enough calcium and vitamin D every day. These nutrients help prevent osteoporosis, which is responsible for a lot of the bone fractures that lead to back pain.

Calcium is found in dairy products; green, leafy vegetables; and fortified products, like orange juice. Your skin makes vitamin D when you are in the sun. If you are not outside much, you can obtain vitamin D from your diet: almost all milk and some other foods are fortified with this nutrient. Most adults don’t get enough calcium and vitamin D, so talk to your doctor about how much you need per day.

In most cases, it is not necessary to see a doctor for back pain because pain usually goes away with or without treatment. However, a trip to the doctor is a good idea if your pain is severe and doesn’t improve, or if you have pain after a fall or an injury.

It is important to see your doctor if you have pain along with any of the following problems: trouble urinating; weakness, pain or numbness in your legs; fever; or unintentional weight

16 March 2010

Skoliosis: Boleh dirawat melalui pemakanan dan senam (In Malay)

Siapalah yang ingin mempunyai badan yang bengkok angkara tulang belakang yang tidak tumbuh secara normal?

Keadaan ini biasanya disebabkan masalah disebut skoliosis (scoliosis).Untuk merawatnaya, cara biasa yang digunakan ialah memasang pendakap atau braces untuk membetulkan tulang yang bengkok itu.Pembedahan juga boleh di lakukan, tetapi ia boleh memberikan beberapa risiko seperti kehilangan darah yang banyak dan kerosakkkan saraf.

Namun, pesakit skoliosis tidak perlu menjalani prosedur konvensional ini kerana ia bolehdirawat tanpa pembedahan,melalui satu sistem teratur yangmelibatkan perancangan pemakanan yang disesuaikan dengan keperluan pesakit, dan progam senaman yang berstruktur.Seorang doktor yang menjalankan rawatan seperti ini ialah Dr Kevin Lau, seorang pakar dalam bidang rawatan skoliosis tanpa pembedahan dan juga doktor bidang kiropraktik dan permakanan holistik.

Menurut Dr Lau, yang menulis sebuah buku khusus mengenai skoliosis, Health in Your Hands,

penyakit itu adalah satu masalah kesihatan yang berleluasa di seluruh dunia.

Data menunjukan bahawa kedudukan tulang belakang yang tidak normal,yang membawa kepada bentuk tulang yang bengkok, menjejas hampir dua daripada tiga orang remaja dan mula ketara pada usia antara 10tahun dengan 15 tahun apabila seseorang itu pula prihatin dengan bentuk badannya.

Di Singapura pula, seorang daripada setiap 10 orang menghidap apa yang disebut sebagai skoliosis lumbar (bahagian bawah tulang belakang), menurut satu kajian terbaru yang dijalankan sekumpulan pakar bedah tulang belakan, diketuai oleh Profesor Wong Hee Kit, pengerusi Kelompak Ortopedik dan Pembedahan Mikro Tangan dan rekonstruktif di Sistem Kesihatan Universiti National (NUHS).


Apa yang lebih buruk lagi, kajian itu juga mendedeahkan skoliosi dihadapi sebanyak 1.6 kali lebih kerap oleh kaum wanita,berbanding lelaki, dan menjejas dua kali ganda lebih ramai kaum Cina dan Melayu, berbanding India Kata Dr Lau.

Bukunya menyebut tentang seorang kanak-kanak perempuan Susan, yang menghidap skoliosis, semasa usianya 12 tahun, ibunya mengesan ada ketulan kecil di belakang badanya.

Beliau bimbang ketulan itu mungkin tumor, tetapi X-ray yang dijalankan menunjukkan tulang belakang Susan telah tumbuh bengkok dalam bentuk “S”.


Susan rupa-rupanya mengalami skoliosis. Beberapa X-ray yang dijalankan selanjutnya menunjukkan tulang belakangnya bengkok 36 darjah dari garisannya.

Keadaannya disebut doktor sebagai skoliosis idiopatik yang bermaksud puncanya tidak diketahui.

Sekitar 80 peratus pesakit yang mempunyai masalah tulang belakang bengkok tergolong dalam kategori ini. Selebihnya berpunca daripada kecacatan sejak lahir,kecederaan pada tulang belakang dan penyakit saraf dan otot-otot seperti muscular dystrophy.

Dr Lau menarik perhatian bahawa rawatan konventional skoliosis biasanya memerlukan pesakit menunggu dan melihat sejauh mana tulangnya telah bengkok melalui pemeriksaan setiap enam bulan atau setiap tahun. Jika tulang itu bengkok antara 25 dengan 40 darjah,pesakit biasanya disarankan menggunakkan pendakap; Kalau ia bengkok teruk melebihi 40 darjah,barulah pembedahan disarankan sebagai langkah terakhir kata Dr Lau.

Bagaimanapun katanya ramai ibu bapa dan pesakit tidak mahu menunggu dan melihat sejauh mana masalah skoliosis yang dihadapi telah menjadi lebik teruk.Mereka mahu sesuatu dilakukan lebih awal untuk mengelakkan penyakit itu daripada menjadi lebih buruk.Di sinilah kaedah kaedah yang saya gunakan memberikan perbezaan.

Walau bagaimanapun teruk sekalipun keaadan pesakit,kaedah saya boleh digunakan untuk apa jua peringkat skoliosis kerana tujuan utamanya ialah membaiki kesihatan pesakit dan senaman yang disarankan katanya lagi.

Buku ini boleh dibeli di kedai-kedai buku utama di sini dengan harga $38 (termasuk GST) senaskhah.Keterangan langut megenai buku ini boleh didapati di laman web

US soft drinks firms say sugary sodas cut in schools

The US soft drinks industry says it has dramatically cut the number of high-calorie soft drinks sold in US schools as part of a drive to tackle obesity.

The American Beverage Association said shipments of full-calorie drinks to schools were down 95%.

Nearly one in three children and teenagers in the US are overweight or obese and health experts say sugary drinks are part of the problem.

Several US states and cities are considering taxing soft drinks.

The reduction in sugary soft drinks in schools formed part of a deal between the major companies and the Alliance for a Healthier Generation, a joint initiative of the American Heart Association and the Clinton Foundation.

Under the voluntary guidelines, in place since 2006, full-calorie soft drinks were removed from school canteens and vending machines. Lighter drinks, including low-fat milk, diet sodas, juices, flavoured waters and teas were promoted in their place.

"There's been a dramatic shift toward lower calorie and more nutritious beverages in schools, it could lay the foundation for broader changes in our society," former US President Bill Clinton told a news conference on Monday.

Soda tax

Independent consulting firm Keybridge Research looked at what changes the guidelines had brought about and found that:

the total beverage calories shipped to schools between the first half of the 2004-05 school year and the first half of the 2009-10 school year has decreased by 88%
there had been a dramatic shift toward lower-calorie and higher nutrient beverages in schools, including waters, 100% juices, and portion-controlled sports drinks
shipment volumes of full-calorie drinks were 95% lower in the first half of the 2009-10 school year compared with the first half of the 2004-05 school year.
The soft drinks industry has been a main target of critics who say the sugary beverages they sell are a key factor in the levels of childhood obesity in the US.

The state of California and the city of Philadelphia have introduced legislation to tax soft drinks, while both the New York Governor David Paterson and New York City Mayor Michael Bloomberg are also pushing for such a tax.

"In these tough economic times, easy fixes to our problems are hard to come by," said Mr Bloomberg at the weekend. "But the soda tax is a fix that just makes sense, it would cut rising health costs."

Susan Neely of the American Beverage Association, which includes major firms like Coca Cola, PepsiCo and Dr Pepper Snapple Group, said such a tax would not solve "a complex problem like obesity".

Get a copy of this months Ezyhealth & Beauty for a chance to win my book!

Studies support association of higher vitamin D levels with disease risk reduction

The results of two studies conducted by Intermountain Medical Center Heart Institute in Murray Utah, presented on March 15, 2010 at the American College of Cardiology's 59th annual scientific session in Atlanta, show that individuals who increase their vitamin D levels experience a lower risk of cardiovascular disease, heart attack, heart failure, high blood pressure, diabetes, depression, kidney failure and all-cause mortality over a given period of time.

The first study included 9,491 participants in whom low vitamin D levels of 30 nanograms per milliliter (considered "normal" by some practitioners) or less were detected. Nearly 80 percent of the subjects were women. Among the 47 percent who increased their vitamin D levels to 30 nanograms per milliliter or more between their initial and follow-up examinations, there was a decrease in the risk of coronary artery disease, heart failure, renal failure and death compared with those whose vitamin D levels failed to reach this level.
In the second study, the disease-predictive value of varying levels of vitamin D in 31,289 subjects aged 50 and older was analyzed. The researchers concluded that having a vitamin D level of greater than 43 nanograms per milliliter was optimal to significantly lower the risk of seven out of ten outcomes during the period examined: death, diabetes, coronary artery disease, myocardial infarction, heart failure, depression and renal failure.

"It was very important to discover that the 'normal' levels are too low," noted research team member Dr Heidi T. May. "Giving physicians a higher level to look for gives them one more tool in identifying patients at-risk and offering them better treatment."

"Vitamin D replacement therapy has long been associated with reducing the risk of fractures and diseases of the bone," noted Joseph Brent Muhlestein, MD, who is the director of cardiovascular research at the Intermountain Medical Center Heart Institute and co-researcher in both studies. "But our findings show that vitamin D could have far greater implications in the treatment and reduction of cardiovascular disease and other chronic conditions than we previously thought."

Dr Muhlestein remarked that increasing vitamin D intake by supplementing with 1,000 to 5,000 international units per day may be appropriate for some people.

"Although randomized trials would be useful and are coming, I feel there is enough information here for me to start treatment based on these findings," he added.

15 March 2010

Tax soda, pizza to cut obesity, researchers say

(Reuters) - U.S. researchers estimate that an 18 percent tax on pizza and soda can push down U.S. adults' calorie intake enough to lower their average weight by 5 pounds (2 kg) per year.


The researchers, writing in the journal Archives of Internal Medicine on Monday, suggested taxing could be used as a weapon in the fight against obesity, which costs the United States an estimated $147 billion a year in health costs.

"While such policies will not solve the obesity epidemic in its entirety and may face considerable opposition from food manufacturers and sellers, they could prove an important strategy to address overconsumption, help reduce energy intake and potentially aid in weight loss and reduced rates of diabetes among U.S. adults," wrote the team led by Kiyah Duffey of the University of North Carolina at Chapel Hill.

With two-thirds of Americans either overweight or obese, policymakers are increasingly looking at taxing as a way to address obesity on a population level.

California and Philadelphia have introduced legislation to tax soft drinks to try to limit consumption.

CDC director Dr. Thomas Frieden supports taxes on soft drinks, as does the American Heart Association.

There are early signs that such a policy works.

Duffey's team analyzed the diets and health of 5,115 young adults aged age 18 to 30 from 1985 to 2006.

They compared data on food prices during the same time. Over a 20-year period, a 10 percent increase in cost was linked with a 7 percent decrease in the amount of calories consumed from soda and a 12 percent decrease in calories consumed from pizza.

The team estimates that an 18 percent tax on these foods could cut daily intake by 56 calories per person, resulting in a weight loss of 5 pounds (2 kg) per person per year.

"Our findings suggest that national, state or local policies to alter the price of less healthful foods and beverages may be one possible mechanism for steering U.S. adults toward a more healthful diet," Duffey and colleagues wrote.

In a commentary, Drs. Mitchell Katz and Rajiv Bhatia of the San Francisco Department of Public Health said taxes are an appropriate way to correct a market that favors unhealthy food choices over healthier options.

They argued that the U.S. government should carefully consider food subsidies that contribute to the problem.

"Sadly, we are currently subsidizing the wrong things including the product of corn, which makes the corn syrup in sweetened beverages so inexpensive," they wrote.

Instead, they argued that agricultural subsidies should be used to make healthful foods such as locally grown vegetables, fruits and whole grains less expensive.