Monday, February 28, 2011
With one-third of Americans obese and many more overweight, the nation is desperate for a weight-loss miracle. But the return of the hCG diet -- a fad popular in the 1970s that combines daily injections of "human chorionic gonadotropin" and extreme
caloric restriction -- has some weight-loss experts worried.
"We're so desperate to have good solutions for weight control that a lot of people with good common sense literally suspend it when it they confront weight-loss
claims," Dr. David Katz, director of the Yale University Prevention Research Center, said. "This diet is appalling. It takes irresponsible diets to new heights."
HCG is a hormone first produced by the developing embryo and then the placenta during pregnancy to help nourish the womb. Because calories are re-routed from mother to fetus during pregnancy, hCG diet promoters say, injecting the hormone will help curb appetite and allow dieters to get through a day on the energy equivalent of a turkey sandwich.
"A 500-calorie-a-day diet is just plain dangerous," Katz said. "When you restrict calories to that level, there's a real risk for not providing your body with
enough essential amino acids, so it scavenges itself. In some instances, it can cause the body to scavenge from critical places, like the heart."
The danger of very low-calorie diets has been well documented since their rise in popularity in the '70s. A 1981 study published in the American Journal of
Clinical Nutrition described 17 people, all of whom were initially obese and had significant and rapid weight loss, who died suddenly of ventricular arrhythmia after a median five months of dieting.
The lowest recommended caloric intake per day is 1,200 calories for women and 1,500 for men,according to the National Institutes of Health.Restricting calories beyond those limits should only be done under doctor supervision because of the health risks.
Some milder versions of the hCG diet allow dieters to consume 800 calories per day, and use hormone creams or drops instead of injections. "Frankly, it's all variations of the same nonsense," Katz said, calling hCG injections an expensive placebo effect.
Source:KATIE MOISSE, ABC News Medical Unit 2/28/11
Sunday, February 27, 2011
Since Vitamin D has been in the news recently, I thought it would be helpful to see which foods have high levels of this important vitamin. This list is provided by the Office of Dietary Supplements at the National Institute of Health.
Food IUs per serving*
Cod liver oil, 1 tablespoon 1,360
Salmon (sockeye), cooked, 3 ounces 447
Mackerel, cooked, 3 ounces 388
Tuna fish, canned in water, drained, 3 ounces 154
Milk, nonfat, reduced fat, and whole, vitamin D-fortified, 1 cup 115-124
Orange juice fortified with vitamin D, 1 cup (check product labels, as amount of added vitamin D varies) 100
Yogurt, fortified with 20% of the DV for vitamin D, 6 ounces (more heavily fortified yogurts provide more of the DV) 80
Margarine, fortified, 1 tablespoon 60
Liver, beef, cooked, 3.5 ounces 49
Sardines, canned in oil, drained, 2 sardines 46
Egg, 1 large (vitamin D is found in yolk) 41
Ready-to-eat cereal, fortified with 10% of the DV for vitamin D, 0.75-1 cup (more heavily fortified cereals might provide more of the DV) 40
Cheese, Swiss, 1 ounce 6
* IUs = International Units.
Children with low levels of vitamin D have increased risk of developing allergies, New York researchers say.
Senior author Dr. Michal Melamed of the Albert Einstein College of Medicine at Yeshiva University looked at the serum vitamin D levels in blood collected in 2005-2006 from a nationally representative sample of more than 3,100 children and adolescents as well as 3,400 adults.
One of the blood tests assessed was sensitivity to 17 different allergens by measuring levels of Immunoglobulin E, a protein made when the immune system responds to allergens.
The research team found no association between vitamin D levels and allergies in adults, but for children and adolescents, low vitamin D levels correlated with sensitivity to 11 of the 17 allergens tested, including both environmental allergens such as ragweed, oak, dog, cockroach and food allergens such as peanuts.
The study, published in the Journal of Allergy and Clinical Immunology, found children who had vitamin D deficiency -- defined as less than 15 nanograms of vitamin D per milliliter of blood -- were 2.4 times more likely to have a peanut allergy than were children with sufficient levels of vitamin D
Read more: http://www.upi.com/Health_News/2011/02/24/Low-vitamin-D-kids-higher-allergy-risk/UPI-11821298592375/#ixzz1FCz87rkn
Monday, February 14, 2011
The idea seems sort of silly, just another exercise gimmick. Stand for a few minutes on a platform that vibrates. Get off and try to do some weight lifting — squats, for example. Or try a short sprint. Or see how high you can jump. You are somehow supposed to be able to lift heavier weights, sprint faster, jump higher.
But maybe it’s not so silly, exercise physiologists say. Although they don’t really know why vibrations should work, researchers report that they actually seem to slightly improve performance in the few minutes after a person gets off the machine.
The problem, though, is that there is little consensus on how fast the vibrations should be or in what direction platforms are supposed to vibrate. Some studies have failed to show any effects from vibrations. And then there is the question of what exactly vibrations are doing to muscles and nerves.
“It certainly is intriguing, and a large portion of the evidence would support that something is happening,” said Lee E. Brown, director of the Center for Sports Performance at California State University, Fullerton. But he added, “We are still trying to figure out exactly what the mechanism is.”
Meanwhile, several companies make the vibrating platforms, and they are being used at gyms and by some athletes.
One company, Power Plate, proclaims that stars like Serena Williams and Justin Morneau, of the Minnesota Twins, train with its device. A testimonial for another company, Wave, says the United States ski and snowboard teams used its vibrating plates in training for the 2010 Winter Olympics.
But researchers are wary.
“There is something to it,” said William J. Kraemer, a professor of kinesiology at the University of Connecticut and the editor in chief of The Journal of Strength & Conditioning Research, calling it “another tool” for athletic conditioning. But he added that other conditioning methods might yield the same or better results.
“If you think of conditioning as a toolbox, there are lots of tools,” he said. “But when companies are selling something, they want to pretend that one tool does everything.”
Experts who have tried the platforms describe them in different ways. The sensation is nothing like using a jackhammer, said Hugh Lamont, a sports biomechanist at East Tennessee State University. Most vibration plates move no more than 50 times a second and feel like the vibrations in a seat over the wheel hub on a bus, Dr. Lamont said.
Others say the vibrations remind them of downhill skiing — they get the same sort of the rattling in their legs and feet. For Jeffrey M. McBride, an associate professor of biomechanics who is director of the neuromuscular laboratory at Appalachian State University in Boone, N.C., the word that comes to mind is “weird.”
“You can feel your muscles contract,” he said. “It sort of fatigues you.”
But if there is an effect, the researchers said, it seems to be short-lived. People seem to be slightly faster sprinters immediately after standing on a platform. They also seem to be able to jump a bit higher. Vibrations also seem to help people warm up before more strenuous exercise.
“The effect wears off very quickly,” Dr. Brown said. “We are not talking about using this to play a 90-minute soccer match. One sprint and the effect would be gone. You’d play for one minute and still have 89 minutes to go.”
But it could make a difference, he said, if an athlete is about to try a penalty kick in soccer or swing a bat in baseball.
And Michael G. Bemben, chairman of exercise science at the University of Oklahoma, said that “one thought was if you were, say, a high jumper on your third trial in the Olympics and you are at 7 feet 2 inches and need to get to 7 feet 3, this might give you the power for that jump.”
Investigators say they can only guess why vibrations might improve performance. Their leading hypothesis is that it somehow mimics the effect of following a difficult task with an easier one — a simple technique that has been in use for years.
“If you pick up something heavy and then pick up something considerably lighter,” Dr. Lamont explained, “you might be able to throw the lighter weight farther.”
Or if you want to jump, he continued, you might first put a huge weight on a training rack, do a quarter squat, partway down, and then, for three to five seconds, try to push up and lift the weight. You would be doing an isometric contraction of your leg muscles. After that, you might jump higher.
But does it matter? Why not just warm up in the normal way, or do isometric contractions before jumping, or pick up a heavy weight before trying to throw a lighter one?
Or why not combine everything and do warm-ups on a vibrating platform, or try isometric contractions between periods of vibration?
Researchers have thought of that, and say they are investigating. Meanwhile, they say, people should be appropriately skeptical about the effects of standing on a vibrating platform.
“We don’t know a lot about prescribing it,” Dr. Kraemer said. “There’s the rub.”
And yet it is being used many times without an understanding of how to do it best or what the long-term training effects will be.
“Research,” Dr. Kraemer said, “is trying to catch up.”
Source: New York Times 2/11/11
he calorie-burning benefits of exercise don't stop after the treadmill does. A study finds that after exercising vigorously, a substantial calorie burn may follow.
The small study involved 10 healthy men, age 22 to 33, of various body mass indexes and aerobic fitness levels. Their calorie expenditure was measured after they exercised vigorously for 45 minutes, as well as on a rest day. Activity, rest, plus eating meals and snacks were all done under carefully controlled conditions so researchers could get an accurate assessment of calories taken in and burned.
The 45-minute exercise session (done on a cycle ergometer) burned an average 519 calories -- not bad for a workout. But the big news is what came afterward. In 14.2 hours following the exercise bout, calorie expenditure was elevated, resulting in about 190 extra calories burned.
While that may not seem like much, think of it as being able to eat about three Pepperidge Farms Milano cookies with no consequences, or getting the calorie burn of a 30-minute walk at 4 mph for free.
The authors wrote that the calorie burn could be substantial if two or three of those high-intensity bouts of exercise are done a week, and eating is kept under control.
Source: Medicine & Science in Sports & Exercise.
Chicago Tribune.com 2/11/11
Wednesday, February 9, 2011
A diet, high in fats, sugars, and processed foods in early childhood may lower IQ, while a diet packed full of vitamins and nutrients may do the opposite, suggests research published online in the Journal of Epidemiology and Community Health.
Parents completed questionnaires, detailing the types and frequency of the food and drink their children consumed when they were 3, 4, 7 and 8.5 years old.
Three dietary patterns were identified: "processed" high in fats and sugar intake; "traditional" high in meat and vegetable intake; and "health conscious" high in salad, fruit and vegetables, rice and pasta. Scores were calculated for each pattern for each child.
IQ was measured using a validated test (the Wechsler Intelligence Scale for Children) when they were 8.5 years old. In all, complete data were available for just under 4,000 children.
The results showed that after taking account of potentially influential factors, a predominantly processed food diet at the age of 3 was associated with a lower IQ at the age of 8.5, irrespective of whether the diet improved after that age. Every 1 point increase in dietary pattern score was associated with a 1.67 fall in IQ.
On the other hand, a healthy diet was associated with a higher IQ at the age of 8.5, with every 1 point increase in dietary pattern linked to a 1.2 increase in IQ. Dietary patterns between the ages of 4 and 7 had no impact on IQ.
"This suggests that any cognitive/behavioural effects relating to eating habits in early childhood may well persist into later childhood, despite any subsequent changes (including improvements) to dietary intake," researchers say.
The brain grows at its fastest rate during the first three years of life, say the authors, by way of a possible explanation for the findings, adding that other research has indicated that head growth at this time is linked to intellectual ability.
"It is possible that good nutrition during this period may encourage optimal brain growth," they suggest, advocating further research to determine the extent of the effect early diet has on intelligence.
Source: ScienceDaily (Feb. 8, 2011)
Friday, February 4, 2011
Based on past research which showed people increased their caffeine intake when under stress, three researchers from the University of Bristol took this science further in investigating whether caffeine did indeed increase performance at work. Their finding: "we found that women performed better than did men on collaborative tasks under stress, provided caffeine had been consumed."
The importance of this study as stated by the researchers is intriguing:"The present study also suggests that further research is needed to discover whether caffeinated drinks at business meetings might unintentionally sabotage the partnerships forged to solve stressful issues that the meetings were designed to facilitate. This need is all the more urgent because many such meetings, including those at which military and other decisions of great import are made, are likely to be male-dominated." (p.3125)
Source: Journal of Applied Social Psychology, Volume 40, issue 12 (December 2010), p. 3106-3129
Tuesday, February 1, 2011
Watching what you eat takes on a whole new meaning after reading this article written by Janet Roloff with Science News.
There’s little doubt that humanity has been tipping the scales at increasingly higher weights and rates. A study now lends support to the idea that meal-time distractions can mask the cues that we really have eaten quite enough. Moreover, it finds, the caloric fallout of not paying attention to what we’re eating doesn’t necessarily end when a meal is over.
Rose Oldham-Cooper of the University of Bristol, England, and her colleagues recruited 22 men and an equal number of women for a luncheon experiment. Each person dined alone, sequentially receiving nine small portions of food items. These ranged from cheese twists and potato chips to carrots, cherry tomatoes and sandwiches or sausage rolls.
Because the goal was to test the potential impacts of distraction on satiety, the researchers randomly assigned half of the participants to eat in front of a computer — and to rack up as many wins as possible at the “card” game solitaire. Everyone else was told to focus on the sensory attributes of their meal.
Per their instructions, the recruits ate all of the food given them. Yet people who played a computer game during lunch found their meal substantially less filling than the mindful eaters had. Game players also scarfed down twice as many cookies, almost an hour later, when they were allowed all the dessert they wanted (under the guise of a taste test). The British scientists present their findings in the February American Journal of Clinical Nutrition.
Earlier research by others had shown distraction can speed our feeding rate, potentially fostering overconsumption. So Oldham-Cooper’s team provided each participant his or her food at a precise, timed rate. The new findings can’t, therefore, be chalked up to half of the participants simply eating too fast for their bodies to gauge.
“Our findings are highly relevant to today’s society where a multitasking mentality is especially prevalent,” the authors say. Particularly troubling, they note: “One U.S. study reported that up to one-quarter of children’s total energy intake was consumed while watching television . . . [and] in a study of overweight women, almost one-half of all weekly meals were reportedly consumed in a room with a television set switched on.”
The real question is why distracted eating should impact subsequent snacking. It appears, the scientists say, that memory plays some subtle role in how we register what we eat and the degree to which it satisfies.
Interestingly, eight years ago, Britta Barkeling of Huddinge University in Stockholm and her colleagues reported somewhat related findings. Their 18 obese subjects had no choice other than to tune out everything but lunch, on one day — because they were blindfolded. Compared to a day when they could view what they were dining on, these people consumed only three quarters as many calories. Yet even hours afterward, they reported being no less sated than on the day they had been able to see their plates.
Of course dining in the dark isn’t practical. And sometimes what we eat doesn’t really invite our rapt attention. But there is certainly a growing mountain of data indicating that mindless eating is a waste of resources, a risk to our waistlines — and a costly threat to health.
Just how costly was indicated by an analysis that I ran across today (while eating at my desk, if I’m to be honest). It pegs the costs associated with obesity at 0.7 to 2.8 percent of a nation’s health care expenditures. One reason, its University of Toronto authors report in Obesity Reviews: “[O]bese individuals were found to have medical costs that were approximately 30 percent greater than their normal-weight peers.”
Source: Science News 1/31/11. Research published in the American Journal of Clincial Nutrition 2/2011