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New research suggests that a calorie-restricted diet higher in protein—mostly from dairy foods—and lower in carbohydrates coupled with daily exercise has a major positive impact on bone health in overweight and obese young women.
The study, published online in the Journal of Clinical Endocrinology and Metabolism, found bone health improvements were particularly evident due to the high density of bone-supporting nutrients such as calcium, vitamin D and dairy-based protein.
For 16 weeks, three groups of overweight and obese, but otherwise healthy, premenopausal women each consumed either low, medium or high amounts of dairy foods coupled with higher or lower amounts of protein and carbohydrates. Calcium and vitamin D levels were also graded from low to high across the groups in conjunction with the dairy foods they consumed.
The women exercised seven days per week, a routine that included aerobic exercise every day and two additional workouts of circuit weightlifting per week.
“Our findings demonstrate the importance of diet composition to the maintenance of bone health status during weight loss,” said Andrea Josse, of the Department of Kinesiology at McMaster and lead author of the study. “Our data clearly show dairy-source protein is important when aiming to avoid harmful consequences such as accelerated bone loss during weight loss. In our view, young women attempting to lose weight should consume a diet higher in dairy-source protein.”
A previous study from the same team in the same subjects showed that there were identical total weight losses across the groups, but very different results for body composition change with the higher-protein, high-dairy group experiencing greater whole-body fat and abdomen fat losses and greater lean mass gains.
The same subjects consuming higher-protein and high-dairy diets for this study also showed the greatest improvements in markers of bone formation, no change in bone loss, an increase in circulating vitamin D levels, and a decrease in levels of parathyroid hormone, which when elevated is typically associated with bone loss.
Maintaining or even improving bone health in young women, particularly in those trying to lose weight, is important for overall health, and may have great implications for decreasing the risk of diseases like osteoporosis later in life, say the researchers.
“Our data provide further rationale to recommend consumption of dairy foods to aid in ‘high quality’ weight loss, which we defined as loss of fat and sparing of muscle, and the promotion of bone health in young women,” says Stuart Phillips, senior author and a professor in the Department of Kinesiology. “These women are not only at the age when achieving and maintaining peak bone mass is of great importance, but in whom adequate dairy consumption would offset sub-optimal intakes of calcium and vitamin D.”
Subjects undergoing weight loss while consuming marginally adequate protein without dairy foods showed markedly elevated levels of markers of bone loss indicating that following such a diet in the long-run would weaken bones.
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Wednesday, November 30, 2011
Monday, November 28, 2011
Mid-morning snacking may sabotage weight-loss efforts
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Finding may not relate to time of day, but to the short interval between breakfast and lunch
Women dieters who grab a snack between breakfast and lunch lose less weight compared to those who abstain from a mid-morning snack, according to a study led by researchers at Fred Hutchinson Cancer Research Center.
The results of this randomized trial, led by Anne McTiernan, M.D., Ph.D., a member of the Hutchinson Center’s Public Health Sciences Division and director of its Prevention Center, will be published in the December issue of the Journal of the American Dietetic Association.
In the course of the year-long study, the researchers found that mid-morning snackers lost an average of 7 percent of their total body weight while those who ate a healthy breakfast but did not snack before lunch lost more than 11 percent of their body weight. For the study, a snack was defined as any food or drink that was consumed between main meals.
“We think this finding may not relate necessarily to the time of day one snacks, but rather to the short interval between breakfast and lunch. Mid-morning snacking therefore might be a reflection of recreational or mindless eating habits rather than eating to satisfy true hunger,” said McTiernan, the corresponding author of the paper.
While snacking too close to a main meal may be detrimental to weight loss, waiting too long between meals also may sabotage dieting efforts, she said. “Snacking could be part of a dieter’s toolkit if they’re eating in response to true hunger. Individuals should determine if they experience long intervals – such as more than five hours – between meals. Adding a snack might help people deal better with hunger and ultimately help them to make more sound choices at their next meal.”
The study also revealed that women who reported eating more than two snacks a day had higher fiber intake than those who snacked less frequently, and afternoon nibblers ate more fruits and vegetables compared to women who didn’t snack between lunch and dinner.
The ancillary study, part of a larger randomized clinical trial designed to test the effects of nutrition and exercise on breast cancer risk, involved 123 overweight-to-obese postmenopausal Seattle-area women, ages 50 to 75, who were randomly assigned to either a diet-alone intervention (goal: 1,200 to 2,000 calories a day, depending on starting weight, and fewer than 30 percent of daily calories from fat), or diet plus exercise (same calorie and fat restrictions plus 45 minutes of moderate-to-vigorous exercise per day, five days a week). While the women received nutrition counseling they were not given any specific instructions or recommendations about snacking behavior.
At the end of the study the women were asked to record the time, type and frequency of meals consumed on a normal day. Percent of calories from fat, fiber and fruit and vegetable intake were also estimated using a food-frequency questionnaire.
“Many people think that a weight-loss program has to mean always feeling hungry,” McTiernan said. “Our study suggests that snacking may actually help with weight loss if not done too close to another meal, particularly if the snacks are healthy foods that can help you feel full without adding too many calories.”
Nationwide surveys indicate that 97 percent of U.S. adults report snacking, and such behavior is consistent across age groups. One study that surveyed a national random sample of more than 1,500 adults found that the most commonly preferred snacks were salty and crunchy items such as potato chips, pretzels and nuts; baked goods such as cookies and cakes; fruits; and ice cream.
Not all snacks are created equal, however. Foods less conducive to weight loss include empty-calorie items that contribute fat, salt, sugar and little nutritional value, such as potato chips and sugar-sweetened beverages.
For a woman on a weight-loss diet, a healthy snack should pack a nutritional wallop without breaking the calorie bank. “Since women on a weight-loss program only have a limited number of calories to spend each day, it is important for them to incorporate nutrient-dense foods that are no more than 200 calories per serving,” McTiernan said. “The best snacks for a weight-loss program are proteins such as low-fat yogurt, string cheese, or a small handful of nuts; non-starchy vegetables; fresh fruits; whole-grain crackers; and non-calorie beverages such as water, coffee and tea.”
The National Cancer Institute funded the research and participated in the study, which also involved investigators from the University of Washington and the University of Illinois at Chicago.
Finding may not relate to time of day, but to the short interval between breakfast and lunch
Women dieters who grab a snack between breakfast and lunch lose less weight compared to those who abstain from a mid-morning snack, according to a study led by researchers at Fred Hutchinson Cancer Research Center.
The results of this randomized trial, led by Anne McTiernan, M.D., Ph.D., a member of the Hutchinson Center’s Public Health Sciences Division and director of its Prevention Center, will be published in the December issue of the Journal of the American Dietetic Association.
In the course of the year-long study, the researchers found that mid-morning snackers lost an average of 7 percent of their total body weight while those who ate a healthy breakfast but did not snack before lunch lost more than 11 percent of their body weight. For the study, a snack was defined as any food or drink that was consumed between main meals.
“We think this finding may not relate necessarily to the time of day one snacks, but rather to the short interval between breakfast and lunch. Mid-morning snacking therefore might be a reflection of recreational or mindless eating habits rather than eating to satisfy true hunger,” said McTiernan, the corresponding author of the paper.
While snacking too close to a main meal may be detrimental to weight loss, waiting too long between meals also may sabotage dieting efforts, she said. “Snacking could be part of a dieter’s toolkit if they’re eating in response to true hunger. Individuals should determine if they experience long intervals – such as more than five hours – between meals. Adding a snack might help people deal better with hunger and ultimately help them to make more sound choices at their next meal.”
The study also revealed that women who reported eating more than two snacks a day had higher fiber intake than those who snacked less frequently, and afternoon nibblers ate more fruits and vegetables compared to women who didn’t snack between lunch and dinner.
The ancillary study, part of a larger randomized clinical trial designed to test the effects of nutrition and exercise on breast cancer risk, involved 123 overweight-to-obese postmenopausal Seattle-area women, ages 50 to 75, who were randomly assigned to either a diet-alone intervention (goal: 1,200 to 2,000 calories a day, depending on starting weight, and fewer than 30 percent of daily calories from fat), or diet plus exercise (same calorie and fat restrictions plus 45 minutes of moderate-to-vigorous exercise per day, five days a week). While the women received nutrition counseling they were not given any specific instructions or recommendations about snacking behavior.
At the end of the study the women were asked to record the time, type and frequency of meals consumed on a normal day. Percent of calories from fat, fiber and fruit and vegetable intake were also estimated using a food-frequency questionnaire.
“Many people think that a weight-loss program has to mean always feeling hungry,” McTiernan said. “Our study suggests that snacking may actually help with weight loss if not done too close to another meal, particularly if the snacks are healthy foods that can help you feel full without adding too many calories.”
Nationwide surveys indicate that 97 percent of U.S. adults report snacking, and such behavior is consistent across age groups. One study that surveyed a national random sample of more than 1,500 adults found that the most commonly preferred snacks were salty and crunchy items such as potato chips, pretzels and nuts; baked goods such as cookies and cakes; fruits; and ice cream.
Not all snacks are created equal, however. Foods less conducive to weight loss include empty-calorie items that contribute fat, salt, sugar and little nutritional value, such as potato chips and sugar-sweetened beverages.
For a woman on a weight-loss diet, a healthy snack should pack a nutritional wallop without breaking the calorie bank. “Since women on a weight-loss program only have a limited number of calories to spend each day, it is important for them to incorporate nutrient-dense foods that are no more than 200 calories per serving,” McTiernan said. “The best snacks for a weight-loss program are proteins such as low-fat yogurt, string cheese, or a small handful of nuts; non-starchy vegetables; fresh fruits; whole-grain crackers; and non-calorie beverages such as water, coffee and tea.”
The National Cancer Institute funded the research and participated in the study, which also involved investigators from the University of Washington and the University of Illinois at Chicago.
Wednesday, November 16, 2011
Willpower no match for cheap food, big portions
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Ditching the diet for Thanksgiving? Turkey with all the fixings isn't the only temptation causing would-be dieters to miss their goals, according to a new Cornell University review article that finds powerful environmental cues are subconsciously bending willpower every day.
"We're slaves to our environment," said David Levitsky, professor of nutritional sciences and of psychology at Cornell, who co-authored the article with graduate student Carly Pacanowski.
The article, "Free Will and the Obesity Epidemic," will be published in an upcoming print edition of the journal Public Health Nutrition (http://bit.ly/sYl5hJ).
Levitsky and Pacanowski analyzed hundreds of articles on eating behavior and found forces that individuals have no control over are heavily influencing the obesity epidemic in the United States. These forces include cheap food prices and ease of access to unhealthy food. Social factors such as seeing others eat are also strong stimulants, Levitsky said, and have taken on more strength in the past 50 to 60 years, as restaurant dining becomes more frequent.
The article finds portion size emerged as one of the most powerful links to overeating. "And it's not just the amount you put on your plate, but also the package size from which the food comes determines how much you will eat," Levitsky said.
The article suggests dieters can weigh themselves and graph the results on a daily basis to counter these forces because it boosts one's awareness of unconscious eating. It also suggests that the government plays a role in combating the obesity epidemic by subsidizing fruits and vegetables, making low-calorie foods cheaper.
Ditching the diet for Thanksgiving? Turkey with all the fixings isn't the only temptation causing would-be dieters to miss their goals, according to a new Cornell University review article that finds powerful environmental cues are subconsciously bending willpower every day.
"We're slaves to our environment," said David Levitsky, professor of nutritional sciences and of psychology at Cornell, who co-authored the article with graduate student Carly Pacanowski.
The article, "Free Will and the Obesity Epidemic," will be published in an upcoming print edition of the journal Public Health Nutrition (http://bit.ly/sYl5hJ).
Levitsky and Pacanowski analyzed hundreds of articles on eating behavior and found forces that individuals have no control over are heavily influencing the obesity epidemic in the United States. These forces include cheap food prices and ease of access to unhealthy food. Social factors such as seeing others eat are also strong stimulants, Levitsky said, and have taken on more strength in the past 50 to 60 years, as restaurant dining becomes more frequent.
The article finds portion size emerged as one of the most powerful links to overeating. "And it's not just the amount you put on your plate, but also the package size from which the food comes determines how much you will eat," Levitsky said.
The article suggests dieters can weigh themselves and graph the results on a daily basis to counter these forces because it boosts one's awareness of unconscious eating. It also suggests that the government plays a role in combating the obesity epidemic by subsidizing fruits and vegetables, making low-calorie foods cheaper.
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