Do you really know what a calorie is?

From the NYTimes 

“The human body does a superb job of making sure that it gets enough calories to meet biological needs but is much less effective at knowing when calories are in excess,” they wrote. “The result is that it is much easier to overeat than to stop eating when you are no longer hungry.”
“The human body does a superb job of making sure that it gets enough calories to meet biological needs but is much less effective at knowing when calories are in excess,” they wrote. “The result is that it is much easier to overeat than to stop eating when you are no longer hungry.”

Americans are having a passionate love affair with something they cannot see, hear, feel, touch or taste. That something is calories, billions upon billions of which are consumed every day, often unwittingly, at and between meals. 

Marion Nestle, a professor of nutrition, food studies and public health at New York University; and Malden Nesheim, professor emeritus of nutritional sciences at Cornell University. Together they have written a new book, “Why Calories Count: From Science to Politics,” to be published April 1, which explains what calories are, where they come from, how different sources affect the body, and why it is so easy to consume more of them than most people need to achieve and maintain a healthy weight.

Out of Control

People living in affluent societies today swim in a sea of redundant calories. Food is everywhere, and it is relatively inexpensive, accounting for about 10 percent of Americans’ disposable income on average, Dr. Nestle said in an interview.

“When did it become O.K. to eat in bookstores?” she asked. “Or in Staples? Bed, Bath and Beyond, or drugstores?”

Portion sizes — especially restaurant portions — have mushroomed out of control, she noted.

“People who pay attention to calorie labels on menus are shocked, for example, to discover that a single cookie contains 700 calories,” Dr. Nestle said. “You may want that cookie, but then you can’t eat anything else. Cookies didn’t used to be this big.”

Nor were bagels, now 500 or 600 calories each, or sodas, available in sizes as large as 64 ounces.

The shock extends to those supposedly in the know. Recently Lisa Young, a colleague of Dr. Nestle at New York University, asked the students in her nutrition class how many calories were in a Double Gulp, a 64-ounce soda available at 7-Eleven convenience stores. She’d already told them that an eight-ounce soda has 100 calories, but the students guessed a Double Gulp contains less than 400 calories.

When Dr. Young asked why their estimate was off by 100 percent, they simply said, “800 calories — that can’t be!”

People who do check calorie information on nutrition labels often fail to note the size of the serving it applies to. A serving of ice cream is just a half-cup, a burger is three ounces, and uncooked pasta is merely two ounces. A pound of pasta, therefore, should feed eight people, not two or four; two ounces per serving is about what Italians consume as a first course.

A typical American restaurant meal is more like dinner for two. Dr. Nestle said restaurants have resisted her suggestion to serve half the amount of food for about a third the price. She recently found at one New York restaurant that a “personal-size pizza” contained 2,100 calories, the amount the average woman needs in a day.

“And that didn’t include the soda and dessert,” she said. “Unless you’re in the kitchen watching what the chef is doing, you have no idea how many calories are being packed into a given dish.”

Health claims for foods are another seductive factor encouraging overconsumption, Dr. Nestle said. She’s found that words imparting “a health aura — like ‘organic’ or ‘low-fat’ or ‘heart-healthy’ — can prompt people to forget about calories.”

Ending Excess

The human body has a very complex and redundant system to make sure the brain gets the sugar calories it needs to function, Dr. Nestle and Dr. Nesheim explain in their book. At least 100 different hormones, enzymes and other chemicals — with more likely to be discovered — act to regulate appetite and to assure that people eat enough to maintain brain function.

But it is these very systems that go into overdrive during starvation (translation: a reduced-calorie diet), making it so difficult for people to lose weight.

As seductive as the current food environment is, it is still easier not to gain excess weight in the first place. Most people seriously underestimate how much they eat. For example, participants in the Nurses’ Health Study report consuming 1,600 calories a day, but their body mass index on average is 26 or higher — well into the overweight range and supported by many more calories than the women seem to think they are eating.

“I don’t count calories, and I don’t recommend counting calories,” Dr. Nestle said. “I recommend eating food. You have to pay attention to eating better and in moderation: plenty of fruits and vegetables, lean meats, and whole grains in reasonable portions, and not too much junk food.”

She applauded the current campaign by the New York City Department of Health and Mental Hygiene to get people to stop “pouring on the calories” by consuming fewer sugar-sweetened soft drinks.

Dr. Nestle and Dr. Nesheim also review the weight-regulating effects of different sources of calories. Is it high-fructose corn syrup that makes so many people fat? Are other carbohydrates to blame, or fat — or what?

They found scant evidence to support the popular notion that any one nutrient is responsible for our obesity, or that a low-carbohydrate diet is everyone’s secret to success.

Although a diet low in carbs and high in fats and protein may enhance satiety and curb snacking, few people seem able to refrain indefinitely from the carbohydrate-rich foods they love. The long-term effectiveness of low-carb diets for a vast majority of people who try them has yet to be assessed.

“The source of the calories may make a small difference in weight maintenance or loss, but it appears to be much less important than the ability to resist pressures to overeat calories in general,” the authors wrote.

And since most people cannot come close to estimating how many calories they consume or expend in a day, a better way to monitor intake and output, Dr. Nestle said, is to regularly check the notches on one’s belt or numbers on the scale.

“It’s much easier to lose a pound or two than 20 or 30,” she said.

Of course, the amount of calories consumed is not the only factor influencing weight. Calories expended count as well, and the more active people are, even if they are simply fidgety, the better able they are to balance intake with output.

Israelis pose a no-skinny-models plan to target eating disorders

The Israeli Parliament's move to ban skinny models from appearing in that nation's media may be less momentous than its efforts to thwart Iran's bid to build nuclear weapons. But to the Israeli politicians who sponsored the measure, which won approval in Tel Aviv on Monday, and to American experts oneating disorders, the measure is a clear step toward a key goal: promoting more realistic body images among girls and women.

Less clear is whether such a measure can drive down eating disorders, which are thought to afflict some 7 million American women and 1 million American men, and as many as 2% of Israeli girls ages 14 to 18.

The Israeli measure would ban the use of models on catwalks or in advertising destined for the Israeli market if they "look underweight" or if their body-mass index falls below 18.5 — the World Health Organization's definition of underweight. If Israeli media outlets alter photographs to make models appear thinner, the measure requires them to disclose that fact.

Why It’s SO Important to Keep Moving

From the New York Times

Hoping to learn more about how inactivity affects disease risk, researchers at the University of Missouri recently persuaded a group of healthy, active young adults to stop moving around so much. Scientists have known for some time that sedentary people are at increased risk of developing heart disease and Type 2 diabetes. But they haven’t fully understood why, in part because studying the effects of sedentary behavior isn’t easy. People who are inactive may also be obese, eat poorly or face other lifestyle or metabolic issues that make it impossible to tease out the specific role that inactivity, on its own, plays in ill health.So, to combat the problem, researchers lately have embraced a novel approach to studying the effects of inactivity. They’ve imposed the condition on people who otherwise would be out happily exercising and moving about, in some cases by sentencing them to bed rest.But in the current study, which was published this month in Medicine & Science in Sports & Exercise, the scientists created a more realistic version of inactivity by having their volunteers cut the number of steps they took each day by at least half.They wanted to determine whether this physical languor would affect the body’s ability to control blood sugar levels. “It’s increasingly clear that blood sugar spikes, especially after a meal, are bad for you,” says John P. Thyfault, an associate professor of nutrition and exercise physiology at the University of Missouri, who conducted the study with his graduate student Catherine R. Mikus and others. “Spikes and swings in blood sugar after meals have been linked to the development of heart disease and Type 2 diabetes.”So the scientists fitted their volunteers with sophisticated glucose monitoring devices, which checked their blood sugar levels continuously throughout the day. They also gave the subjects pedometers and activity-measuring armbands, to track how many steps they took. Finally, they asked the volunteers to keep detailed food diaries.Then they told them to just live normally for three days, walking and exercising as usual.Exercise guidelines from the American Heart Association and other groups recommend that, for health purposes, people accumulate 10,000 steps or more a day, the equivalent of about five miles of walking. Few people do, however. Repeated studies of American adults have shown that a majority take fewer than 5,000 steps per day.The Missouri volunteers were atypical in that regard. Each exercised 30 minutes or so most days and easily completed more than 10,000 daily steps during the first three days of the experiment. The average was almost 13,000 steps.During these three days, according to data from their glucose monitors, the volunteers’ blood sugar did not spike after they ate.But that estimable condition changed during the second portion of the experiment, when the volunteers were told to cut back on activity so that their step counts would fall below 5,000 a day for the next three days. Achieving such indolence was easy enough. The volunteers stopped exercising and, at every opportunity, took the elevator, not the stairs, or had lunch delivered, instead of strolling to a cafe. They became, essentially, typical American adults.Their average step counts fell to barely 4,300 during the three days, and the volunteers reported that they now “exercised,” on average, about three minutes a day.Meanwhile, they ate exactly the same meals and snacks as they had in the preceding three days, so that any changes in blood sugar levels would not be a result of eating fattier or sweeter meals than before.And there were changes. During the three days of inactivity, volunteers’ blood sugar levels spiked significantly after meals, with the peaks increasing by about 26 percent compared with when the volunteers were exercising and moving more. What’s more, the peaks grew slightly with each successive day.This change in blood sugar control after meals “occurred well before we could see any changes in fitness or adiposity,” or fat buildup, due to the reduced activity, Dr. Thyfault says. So the blood sugar swings would seem to be a result, directly, of the volunteers not moving much.Which is both distressing and encouraging news. “People immediately think, ‘So what happens if I get hurt or really busy, or for some other reason just can’t work out for awhile?’” Dr. Thyfault says. “The answer seems to be that it shouldn’t be a big problem.” Studies in both humans and animals have found that blood sugar regulation quickly returns to normal once activity resumes.The spikes during inactivity are natural, after all, even inevitable, given that unused muscles need less fuel and so draw less sugar from the blood.The condition becomes a serious concern, Dr. Thyfault says, only when inactivity is lingering, when it becomes the body’s default condition. “We hypothesize that, over time, inactivity creates the physiological conditions that produce chronic disease,” like Type 2 diabetes and heart disease, regardless of a person’s weight or diet.To avoid that fate, he says, keep moving, even if in small doses. “When I’m really busy, I make sure to get up and walk around the office or jog in place every hour or so,” he says. Wear a pedometer if it will nudge you to move more. “You don’t have to run marathons,” he says. “But the evidence is clear that you do need to move.”