Skipping Meals and Metabolism

People often miss meals because they get busy or are trying to lose weight. But how you skip meals, and the amount you eat at your next meal, can affect your overall health.

The scientific data on skipping meals has been confusing. In some studies, fasting has resulted in measurable metabolic benefits for obese people, and in animal studies, intermittent feeding and fasting reduces the incidence of diabetes and improves certain indicators of cardiovascular health. Even so, several observational studies and short-term experiments have suggested an association between meal skipping and poor health.

In recent months, two new studies may help explain how skipping meals affects health.

The most recent study, published this month in the medical journal Metabolism, looked at what happens when people skip meals but end up eating just as much as they would in a normal day when they finally do sit down to a meal. The study, conducted by diabetes researchers at the National Institute on Aging, involved healthy, normal-weight men and women in their 40s. For two months, the study subjects ate three meals a day. For another eight-week period, they skipped two meals but ate the same number of calories in one evening meal, consumed between 4 p.m. and 8 p.m.

The researchers found that skipping meals during the day and eating one large meal in the evening resulted in potentially risky metabolic changes. The meal skippers had elevated fasting glucose levels and a delayed insulin response — conditions that, if they persisted long term, could lead to diabetes.

The study was notable because it followed another study earlier this year that found that skipping meals every other day could actually improve a patient’s health. In that study, published in March in Free Radical Biology & Medicine, overweight adults with mild asthma ate normal meals one day. This was followed by a day of severely restricted eating, when they ate less than 20 percent of their normal caloric intake, or about 400 or 500 calories a day — the equivalent of about one meal. Nine out of 10 study participants were able to stick to the eating plan.

After following the alternate-day dieting pattern for two months, the dieters lost an average of 8 percent of their body weight, and their asthma-related symptoms also improved. They had lower cholesterol and triglycerides, “striking” reductions in markers of oxidative stress and increased levels of the antioxidant uric acid. Markers of inflammation were also significantly lower.

The conclusion, say the authors of the more recent meal-skipping study, is that skipping meals as part of a controlled eating plan that results in lower calorie intake can result in better health. However, skipping meals during the day and then overeating at the evening meal results in harmful metabolic changes in the body.

Developing Your Own Running Strategies

This recent article in the New York Times discusses disassociation. Others focus. I like my iPod while the distance runner I chatted with at a dinner party insists on listening to the cadence of her stride.

What works for you is ultimately about the fact that it works.

What keeps you going?

Tis the season

November 22, 2007, 10:33 am

The Skinny on Holiday Weight Gain

Reports of your holiday weight gain have been greatly exaggerated. Media stories often suggest that the average person gains 7 to 10 pounds between Thanksgiving and Christmas. And in surveys, people say they gain, on average, about five pounds this time of year.

But several studies now show that the average weight gain during the winter holidays is just one pound.

The news isn’t all good. Most people don’t ever lose the pound of weight they put on during the holidays, according to a report in The New England Journal of Medicine. Since the average weight gain during adulthood is about one to two pounds a year, that means much of midlife weight gain can be explained by holiday eating.

For people who are already overweight, the holiday weight news is worse. Although the average gain is only one pound, people who are already overweight tend to gain a lot more. One study found that overweight people gained five pounds or more during the holidays.

And we start packing on that extra pound of holiday weight early in life. Researchers at the University of Oklahoma studied holiday weight gain among college students during the Thanksgiving break. The students were weighed the day before Thanksgiving, then weighed again about two weeks later. The average weight gain for the 94 students was about one pound. Students who were of normal weight gained about a half a pound during the period. Students who were overweight, meaning their body mass index was 25 or more, gained about two pounds.

Holly Hull, the lead researcher on the Oklahoma study, says Thanksgiving marks the beginning of a “high risk” time for the overweight. “I think the number of people who only overeat at the Thanksgiving meal is slim to none,'’ said Dr. Hull. “The holiday season doesn’t represent one day of overeating. You have this period that extends through the new year where there’s more alcohol, more snacks, more finger foods and appetizers that are energy dense.'’

Running Resources

If you're looking for a race, theschedule.com is the first place you should go. You can search it by location and race type.

To map your own running routes and gauge distance, visit walkjogrun.net.

Empty calories+empty glass= full sized

Nutritionists: Soda making Americans drink themselves fat

By Caleb Hellerman
CNN

(CNN) -- If you're searching for a villain in America's obesity epidemic, most nutritionists tell you to put one picture on the wanted poster: a cold, bubbly glass of soda pop.

"Liquid candy" to detractors, sweetened soft drinks are so ubiquitous that they contribute about 10 percent of the calories in the American diet, according to government data.

In fact, said Dr. David Ludwig, a Harvard endocrinologist whose 2001 paper in the Lancet is widely cited by obesity researchers, sweetened drinks are the only specific food that clinical research has directly linked to weight gain.

"Highly concentrated starches and sugars promote overeating, and the granddaddy of them all is sugar-sweetened beverages," said Ludwig, who runs the Optimal Weight for Life Program at Children's Hospital in Boston.

The rise in soft drink consumption mirrors the national march toward obesity. At the midpoint of the 20th century, Americans drank four times as much milk as soda pop. Today, the ratio is almost completely reversed, according to the U.S. Department of Agriculture. Meanwhile, in the past 30 years the national obesity rate has more than doubled, and among teenagers, more than tripled, reports the Centers for Disease Control and Prevention.

"Soda pop is a quintessential junk food," said Michael Jacobson, who heads the Center for Science in the Public Interest, which lobbies for government restrictions on foods it considers unhealthy. "It's just pure calories, and no nutrients. It's like a bomb in our diet."

Jacobson said the CSPI is pushing to require obesity warning labels on the sides of soda cans, like the surgeon general's warning on cigarettes.

While nutritionists are united in their dislike for nondiet soda, the "why" is controversial.

Some point a finger at high-fructose corn syrup, or HFCS, the sweetener used in most nondiet drinks. Last month, researchers at Rutgers University said they'd identified compounds in HFCS which may start a chemical chain reaction, leading to diabetes.

Most scientists, though, say there's little difference between HFCS and simple sugar, either in chemistry or the way they're handled by the body.

A bigger problem, doctors say, is simply the sheer number of calories. You'll find about 400 calories in a 32-ounce "extra-large" Coke, a fast-food staple. That's nearly a quarter of what the average adult woman needs in a whole day.

Scientists also say the body doesn't respond to liquid calories in the same way it would if those calories came in the form of French fries or chocolate cake. Appetite is controlled by a complex mix of hormones. Some signal the brain that your stomach is getting full. Others, including a hormone known as ghrelin, signal it's time to eat again.

If you eat a big burger, the level of ghrelin drops for a few hours. That drop doesn't happen if you drink a Big Gulp soda, even if it has more calories than the burger, according to Wayne Campbell, a professor in the Department of Foods and Nutrition at Purdue University.

"We're finding your hunger does not go down as far when you consume a beverage, as when you consume a solid," Campbell said. The result: Even with 400 liquid calories in your stomach, you polish off the burger too.

Campbell cautioned that the ghrelin theory isn't proven and that other factors -- such as a food's smell, or the sensation of chewing -- may affect appetite just as much, or even more. Our expectations also play a role.

"Soup is the anomaly to the liquid calorie research," he said. "People perceive soup as a meal, unlike drinking a Coke. So when we've done these types of studies, but used soup as the liquid, we don't see the same differences in [appetite] response."

The sugar in soda pop not only provides a massive dose of calories, but triggers a vicious appetite cycle, said Ludwig, who wrote "Ending the Food Fight," about healthy eating for children.

"It's rapidly absorbed, which raises blood sugar and in effect causes the body to panic." The body releases insulin to break down the sugar, "but the body overcompensates, and blood sugar drops below the fasting level," lower than it was in the first place.

Recognizing low blood sugar, the body releases ghrelin and other hormones, inducing hunger, inducing us to eat even more, Ludwig said.

The public is catching on, he said.

"In our obesity clinic, we used to routinely see patients coming in who were drinking four or five soft drinks a day. Now it's rare. That seems to be the first factor that comes to mind, when people are trying to lose weight."

Soft drink companies, under fire, are taking steps including a pledge last year to phase out nondiet soft drinks from America's schools.

A progress report issued Monday by the American Beverage Association said that shipments to schools of sweetened soda are down 45 percent since 2004, while shipments of bottled water are up 23 percent.

"There's no question the changes that are happening in schools are a mirror of what's happening in the larger marketplace," said Susan Neely, the ABA's president & CEO. "Adults, like kids, are reaching for lower-calorie beverages. ... As a consumer product company, we want to give consumers what they want."

While fighting obesity is complicated, Ludwig said, the first step is clear. "Giving up sugary soda for diet drinks, or water, will cause you to lose weight."

Another Reason to Choose Whole Foods

Some Food Additives Raise Hyperactivity, Study Finds

By ELISABETH ROSENTHAL

Published: September 6, 2007

Common food additives and colorings can increase hyperactive behavior in a broad range of children, a study being released today found.

It was the first time researchers conclusively and scientifically confirmed a link that had long been suspected by many parents. Numerous support groups for attention deficit hyperactivity disorder have for years recommended removing such ingredients from diets, although experts have continued to debate the evidence.

But the new, carefully controlled study shows that some artificial additives increase hyperactivity and decrease attention span in a wide range of children, not just those for whom overactivity has been diagnosed as a learning problem.

The new research, which was financed by Britain’s Food Standards Agency and published online by the British medical journal The Lancet, presents regulators with a number of issues: Should foods containing preservatives and artificial colors carry warning labels? Should some additives be prohibited entirely? Should school cafeterias remove foods with additives?

After all, the researchers note that overactivity makes learning more difficult for children.

“A mix of additives commonly found in children’s foods increases the mean level of hyperactivity,” wrote the researchers, led by Jim Stevenson, a professor of psychology at the University of Southampton. “The finding lends strong support for the case that food additives exacerbate hyperactive behaviors (inattention, impulsivity and overactivity) at least into middle childhood.”

In response to the study, the Food Standards Agency advised parents to monitor their children’s activity and, if they noted a marked change with food containing additives, to adjust their diets accordingly, eliminating artificial colors and preservatives.

But Professor Stevenson said it was premature to go further. “We’ve set up an issue that needs more exploration,” he said in a telephone interview.

In response to the study, some pediatricians cautioned that a diet without artificial colors and preservatives might cause other problems for children.

“Even if it shows some increase in hyperactivity, is it clinically significant and does it impact the child’s life?” said Dr. Thomas Spencer, a specialist in Pediatric Psychopharmacology at Massachusetts General Hospital.

“Is it powerful enough that you want to ostracize your kid? It is very socially impacting if children can’t eat the things that their friends do.”

Still, Dr. Spencer called the advice of the British food agency “sensible,” noting that some children may be “supersensitive to additives” just as some people are more sensitive to caffeine.

The Lancet study focused on a variety of food colorings and on sodium benzoate, a common preservative. The researchers note that removing this preservative from food could cause problems in itself by increasing spoilage. In the six-week trial, researchers gave a randomly selected group of several hundred 3-year-olds and of 8- and 9-year-olds drinks with additives — colors and sodium benzoate — that mimicked the mix in children’s drinks that are commercially available. The dose of additives consumed was equivalent to that in one or two servings of candy a day, the researchers said. Their diet was otherwise controlled to avoid other sources of the additives.

A control group was given an additive-free placebo drink that looked and tasted the same.

All of the children were evaluated for inattention and hyperactivity by parents, teachers (for school-age children) and through a computer test. Neither the researchers nor the subject knew which drink any of the children had consumed.

The researchers discovered that children in both age groups were significantly more hyperactive and that they had shorter attention spans if they had consumed the drink containing the additives. The study did not try to link specific consumption with specific behaviors. The study’s authors noted that other research suggested that the hyperactivity could increase in as little as an hour after artificial additives were consumed.

The Lancet study could not determine which of the additives caused the poor performances because all the children received a mix. “This was a very complicated study, and it will take an even more complicated study to figure out which components caused the effect,” Professor Stevenson said.

Q & A: Sore?

Q: What causes muscle soreness and how is it best relieved?

A: There are two types of exercise-related muscle soreness. Immediate muscle soreness quickly dissipates and is the pain you feel during, or immediately after, exercise. Delayed muscle soreness signals a natural adaptive process that the body initiates following intense exercise. This type of muscle soreness manifests itself 24 to 48 hours after the exercise session and spontaneously decreases after 72 hours.

Numerous studies have been conducted to determine the cause of delayed muscle soreness. The most current consensus attributes this condition to microscopic tears in the muscle and surrounding connective tissue following eccentric exercise. A muscle contracts eccentrically when it lengthens under tension during exercise. For example, during a biceps curl, the biceps muscle shortens during the concentric lifting phase and lengthens during the eccentric lowering phase. Eccentric contractions also occur during aerobic activity, such as downhill running, in which the quadriceps muscle repeatedly lengthens against gravity to lower the center of mass and aid in shock absorption.

Exercisers who experience delayed muscle soreness include conditioned individuals who increase the intensity, frequency or duration of their workouts, or participate in an activity with which they are unfamiliar. Beginning exercisers, or those who have undergone a significant lapse in training, frequently experience soreness when starting or re-engaging in an exercise regimen.

Studies attempting to identify the best methods to alleviate delayed muscle soreness are almost as abundant as the number of studies conducted to determine its cause. Cryotherapy (the topical application of ice), massage, stretching and the use of nonsteroidal, anti-inflammatory drugs (NSAIDs), among other less conventional approaches, have been evaluated to determine if they can prevent or effectively treat delayed muscle soreness. To date, a therapy that consistently relieves delayed muscle soreness has yet to be identified. On the other hand, a few of the aforementioned therapies may have a mild positive impact if initiated immediately after intense or unusual exercise.

Once an individual has experienced delayed muscle soreness at a specific exercise intensity, he or she shouldn't encounter that sensation again until the intensity level is increased. This is because delayed muscle soreness has been shown to produce a rapid adaptation response, which means that the muscles adapt to a given exercise intensity level. Until (or unless) the exercise intensity level is changed, soreness won't occur. This factor is the basis for the most widely recommended approach to preventing delayed muscle soreness: gradual progression and conservative increases in intensity, frequency and duration. Preliminary light exercise may prevent the onset of soreness following a heavy eccentric-exercise workout. Beginners should exercise with light weights, two to three times per week for one to two months, then gradually increase the intensity of their workouts. Conditioned exercisers who want to try a new workout or activity also should begin gradually, taking care not to be overzealous in how hard they exert themselves- particularly until their bodies adapt to the demands imposed upon them.

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Source: Dr. Cedric X. Bryant, ACE's Chief Science Officer; ACE FitnessMatters, Jan/Feb 2007.