Foods rich in protein, dairy products help dieters preserve muscle and lose belly fat: study

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New research suggests a higher-protein, lower-carbohydrate energy-restricted diet has a major positive impact on body composition, trimming belly fat and increasing lean muscle, particularly when the proteins come from dairy products.

The study, published in the September issue of the Journal of Nutrition, compared 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.

The women exercised seven days per week for four months, a routine that included five days of aerobic exercise and two days of circuit weightlifting.

According to the researchers, there were identical total weight losses among the groups, but the higher-protein, high-dairy group experienced greater whole-body fat and abdomen fat losses, greater lean mass gains and greater increases in strength.

The tissue composition, exclusively fat, of the weight the women lost has profound implications for longer-term health, say the researchers.

"One hundred per cent of the weight lost in the higher-protein, high-dairy group was fat. And the participants gained muscle mass, which is a major change in body composition," says Andrea Josse, lead author of the study and a graduate student in the Department of Kinesiology at McMaster University. "The preservation or even gain of muscle is very important for maintaining metabolic rate and preventing weight regain, which can be major problem for many seeking to lose weight."

Researchers found the lower-protein, low-dairy group lost about a pound and half of muscle whereas the lower-protein, medium dairy group lost almost no muscle. In marked contrast, the higher-protein, high-dairy group actually gained a pound and half of muscle, representing a three-pound difference between the low- and high-dairy groups.

On top of the muscle mass differences, the higher-protein, high-dairy group lost twice as much belly fat than the lower-protein, low-dairy group.

"Fat in the abdomen is thought to be especially bad for cardiovascular and metabolic health, and it seems—according to what we found in this study—increasing calcium and protein in the diet may help to further promote loss of fat from the worst storage area in the body," says Josse.

"A very important point is that these changes were not captured by simple measures of body weight or body mass index, which are the most commonly used measures of dietary 'success'" adds Stuart Phillips, a professor in the Department of Kinesiology. "These women also got fitter and stronger, which greatly reduces their risk of disease."

Weight loss without the hunger: eat a lighter lunch

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Losing weight without a grumbling stomach or expensive liquid diet can be as simple as eating a lighter lunch, finds a new Cornell University study to be published in the October issue of the journal Appetite.

Participants who ate portion-controlled lunches did not compensate by eating more calories later in the day, leading researchers to believe the human body does not possess the mechanisms necessary to notice a small drop in energy intake.

"Making small reductions in energy intake to compensate for the increasing number of calories available in our food environment may help prevent further weight gain, and one way of doing this could be to consume portion-controlled lunches a few times a week," said doctoral student Carly Pacanowski, who co-authored the study with David Levitsky, Cornell professor of nutritional sciences and of psychology.

The study closely monitored the food intake of 17 volunteers who ate whatever they wanted from a buffet for one week. For the next two weeks, half the group selected their lunch by choosing from one of six commercially available, portion-controlled foods, such as Chef Boyardee Pasta or Campbell's Soup at Hand, but could eat as much as they wished at other meals or snacks. For the final two weeks, the other half of volunteers followed the same regimen.

While eating portion-controlled lunches, each participant consumed 250 fewer calories per day and lost, on average, 1.1 pounds.

"The results confirm that humans do not regulate energy intake with any precision. Over a year, such a regimen would result in losing at least 25 pounds," said Levitsky, who adds the study demonstrates one simple, low-cost way to consume fewer calories.

Large weight gains most likely for men after divorce, women after marriage

LAS VEGAS — Both marriage and divorce can act as "weight shocks," leading people to add a few extra pounds—especially among those over age 30—according to new research to be presented at the 106th Annual Meeting of the American Sociological Association.

But when it comes to large weight gains, the effects of marital transitions are quite different for men than they are for women.

For men, the risk of a large weight gain increased most prominently after a divorce. But for women, the risk of a large weight gain was most likely after marriage.

"Clearly, the effect of marital transitions on weight changes differs by gender," said Dmitry Tumin, lead author of the study and doctoral student in sociology at Ohio State University.

"Divorces for men and, to some extent, marriages for women promote weight gains that may be large enough to pose a health risk."

The probability of large weight gains following marital transitions increased the most for people past age 30.

"For someone in their mid-20s, there is not much of a difference in the probability of gaining weight between someone who just got married and someone who never married. But later in life, there is much more of a difference," he said.

Tumin conducted the study with Zhenchao Qian, a professor of sociology at Ohio State University.

While there have been many studies about weight gain after marriage or divorce, most of them look at average changes in weight and find very small increases in weight after marriage and often small decreases in weight after divorce.

But these results may mask the fact that some people actually lose weight, while some stay the same, and some have large weight increases, Qian said.

"We estimated the effects of marital transitions on the likelihood of weight gains or losses for different categories of people, allowing for the possibility that not everyone who goes through a marital transition has the same kind of experience," Qian said.

Tumin and Qian used data from the National Longitudinal Survey of Youth '79, a nationally representative sample of men and women aged 14 to 22 in 1979. The same people were surveyed every year up to 1994 and every other year since then.

In this study, the researchers used data on 10,071 people surveyed from 1986 to 2008 to determine weight gain in the two years following a marriage or divorce.

The NLSY included data on Body Mass Index (BMI), a common health measure of weight relative to height.

The researchers separated people into four groups: those who had a BMI decrease of at least 1 kg/m2 (about 7 pounds for a person 5'10" tall) in the two-year period after a marital transition; those who had a small BMI gain (7-20 pounds for the 5'10" person); a large BMI gain (more than about 21 pounds); or no weight gain or loss (net change of less than 7 pounds).

The researchers took into account a wide variety of other factors that may influence weight gain or loss, including pregnancy for women, poverty, socioeconomic status, and education.

Both men and women who married or divorced were more likely than never-married people to have a small weight gain in the two years following their marital transition.

"For most people, the weight gain we see after a marital transition is relatively small, not something we would see as a serious health threat," Tumin said.

However, most other studies have suggested divorce actually leads to weight loss, at least in the first years after the marriage ends. Again, this may be because other studies have not separated people into age and gender groups, and only used average changes in weight, Tumin said.

The data in this study can't reveal why men are more likely to have large weight gains after divorce, while marriage is more likely to cause large weight gains for women.

However, these results fit with other research on how marriage affects men and women.

"Married women often have a larger role around the house than men do, and they may have less time to exercise and stay fit than similar unmarried women," Qian said.

"On the other hand, studies show that married men get a health benefit from marriage, and they lose that benefit once they get divorced, which may lead to their weight gain."

The probability of weight gain becomes more pronounced for men and women who marry or divorce after age 30 and the changes only grow larger as people get older, the study found.

"From age 22 to 30, the effect of marital transitions on weight is not very clear," Qian said.

"But both marriages and divorces increase the risk of weight changes from about age 30 to 50, and the effect is stronger at later ages."

Tumin said that it may be that people settle into certain patterns of physical activity and diet over time. "As you get older, having a sudden change in your life like a marriage or a divorce is a bigger shock than it would have been when you were younger, and that can really impact your weight."

The researchers noted that this study only looked at people for two years after a marital transition, and results may change over the years.

"This study really looks at the shock of a marital transition and how it affects weight," Tumin said.

Lifestyle Change Imperative for Keeping Off Weight

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According to the American Counsel on Exercise only five percent of dieters are successful in keeping off the weight they lost. In fact, one-third of the weight people initially lost is usually gained back within the first year. People who want to lose weight and keep it off have to not only change their ways, but their way of thinking about food, exercise and lifestyle behaviors.
“Diet is only one component of leading a healthy life. To lose and keep weight off, a person needs to stop focusing on the scale and start focusing on becoming a healthier person,” said Valerie Walkowiak, medical integration coordinator at the Loyola Center for Fitness.

The Change Your Weigh program at the Loyola Center for Fitness emphasizes three components needed for a healthier lifestyle: nutrition, behavior modification and exercise. Each component is led by a licensed professional who has received extensive education and training.

Participants meet twice a week. One session is focused on teaching and providing the tools participants need to make healthy choices. The other is a hands-on exercise session.

A registered dietitian teaches participants to shop healthfully, read labels and understand portion control and nutrition labels.

“Many people have the misconception that they have to feel deprived in order to lose weight when that is untrue. People need to learn to eat well, not starve themselves,” said Cris Harder, registered dietician and leader of the Change Your Weigh nutrition program. “Eating right is only one part of losing weight. Diet and exercise need to go hand-in-hand and lifestyle behaviors need to be addressed. Many of us have emotional ties to food and to make a real lifestyle change people need to start thinking about the reason why they eat.”

Licensed clinical social workers lead discussions on topics such as goal-setting, emotional attachment to food and how to overcome barriers.

“Behavior modification helps people to look at the issues that stand in the way of healthy eating and exercise,” said Terri Lee, LCSW. “We help people create personalized strategies for addressing these barriers and obtaining success in their weight loss and lifestyle goals.”

Exercise is the third component for making lifestyle changes. Often, people don’t exercise because they don’t know how or where to start. Each week a personal trainer meets with the group to help participants cross this hurdle.

The personal trainer demonstrates different types of exercise, gives tips on incorporating exercise into daily living, explains exercise guidelines and helps participants learn how to get the most out of their exercise routine. Each week the personal trainer takes participants through a complete workout.

“This is not just a diet program, an exercise class or support group, it’s a combination of all three components.

This program allows participants to gain control of their health because they are given the tools they need to be successful,” said Walkowiak.

Protein preserves muscle and physical function in dieting postmenopausal women

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Dieting postmenopausal women who want to avoid losing muscle as they lose fat should pay attention to a new University of Illinois study. Adding protein throughout the day not only holds hunger pangs at bay so that dieters lose more weight, it keeps body composition—the amount of fat relative to muscle—in better proportion.

"A higher-protein weight-loss diet is more protective of muscle," said Ellen Evans, a former U of I associate professor of kinesiology and community health and member of the university's Division of Nutritional Sciences.

Scientists in Evans's Illinois lab wanted to study the way body composition relates to physical function because older women who diet risk losing muscle as well as fat.

"That loss can affect their strength, balance, and how well they perform everyday tasks, such as climbing stairs and getting up out of a chair," said Mina Mojtahedi, a researcher in Evans's laboratory.

The study shows that higher protein intake during weight loss can offset negative effects on muscle mass by maintaining more muscle relative to the amount of weight lost. Women who ate more protein lost 3.9 percent more weight and had a relative gain of 5.8 percent more thigh muscle volume than woman who did not, she said.

"When a woman has less weight to carry, even if she's lost a bit of lean mass in her legs, the effect is that she has better physical function," she said.

It's likely that such women will be better able to maintain their mobility and independence as they age, she added.

In the six-month double-blind study, 31 healthy, postmenopausal obese women were divided into two groups. Each group followed a 1,400-calorie weight-loss diet based on USDA's My Pyramid, but one group received a powdered whey protein supplement in the morning and again in the afternoon or evening; the other received a placebo that contained carbohydrates.

"We believe it's important to eat protein in the morning and through the day so those amino acids are always available. Unfortunately, American women tend not to eat much protein, especially when they're trying to cut calories. But it's easy to add protein powder into a smoothie or eat a high-protein snack and incorporate a healthier diet into a busy lifestyle," she said.

Both groups were encouraged to engage in light exercise (walking and stretching) and given diet education, including examples of healthy daily menus and a scale to measure portion size.

Before and after the study, participants were assessed for strength, balance, and the ability to perform such physical tasks as walking 50 feet, standing up five times from a chair, and lifting a book 12 inches above shoulder height.

Magnetic resonance imaging (MRI) was used at the beginning and end of the study to measure muscle volume of the right thigh, the amount of fat around the thigh, and the amount of fat within the thigh muscle.

In both groups, strength decreased as weight decreased. However, the study suggests that an increase in the amount of muscle relative to fat had beneficial effects on balance and performance, Evans noted.

And, even though weight loss in these older women had a negative effect on strength, their reduced weight helped with other aspects of physical function, she said.

"We hypothesize that more vigorous exercise—in particular, resistance training—would preserve even more muscle," she said.

Losing weight without thinking about it

Smaller plates, slimmer glasses, linked to weight loss success

Dieters may not need as much willpower as they think, if they make simple changes in their surroundings that can result in eating healthier without a second thought, said a consumer psychologist at the American Psychological Association's 119th Annual Convention.

"Our homes are filled with hidden eating traps," said Brian Wansink, PhD, who presented his findings and strategies for a healthier lifestyle in a plenary address entitled "Modifying the Food Environment: From Mindless Eating to Mindlessly Eating Better."

"Most of us have too much chaos going on in our lives to consciously focus on every bite we eat, and then ask ourselves if we're full. The secret is to change your environment so it works for you rather than against you," Wansink said

Wansink identified several myths about eating behaviors as a way to explain why Americans, on average, have been getting fatter. "People don't think that something as simple as the size of a bowl would influence how much an informed person eats," he said.

However, several studies show exactly that, including Wansink's study of 168 moviegoers, who ate either fresh or stale popcorn from different size containers. People ate 45 percent more fresh popcorn from extra-large containers than large ones and the people who were eating stale popcorn ate 34 percent more from the extra-large buckets than people eating fresh popcorn, according to the study.

They just don't realize they're doing it," said Wansink. This strategy also applies to what we drink. His research found that people pour about 37 percent more liquid in short, wide glasses than in tall, skinny ones of the same volume.

Even a kid's cereal bowl can be a trap, according to Wansink. One study showed children of different weights who were given a 16 ounce bowl were more likely to serve themselves twice as much cereal than children given an 8 ounce bowl.

Another myth, according to Wansink, is that people know when they are full and stop before they overeat. His Food and Brand Lab at Cornell University tested this by designing a "bottomless bowl." They brought in 60 people for a free lunch and gave 22 ounce bowls of soup to half, while the other half unknowingly got 22 ounce bowls that were pressure-fed under the table and slowly refilled. The results: people with bottomless bowls ate 73 percent more than those with normal bowls, yet when asked, they didn't realize they had eaten more. "The lesson is, don't rely on your stomach to tell you when you're full. It can lie," Wansink said.

Simply being aware of such findings can help people make healthier choices, especially those who are already trying to eat healthier foods, according to Wansink. One of his studies showed that people lost up to two pounds a month after making several simple changes in their environment, including:

- eating off salad plates instead of large dinner plates.
- keeping unhealthy foods out of immediate line of sight and moving healthier foods to - eye-level in the cupboard and refrigerator.
- eating in the kitchen or dining room, not in front of the television.

"These simple strategies are far more likely to succeed than willpower alone. It's easier to change your environment than to change your mind," Wansink concluded.