Black Soya Beans May Help Prevent Weight Gain

(HealthDay News) -- New research in rats suggests that black soya beans may be a wonder food of sorts, helping to prevent obesity, lower cholesterol levels and possibly even reduce risks for diabetes.

In a study published in the February issue of the Journal of the Science of Food and Agriculture, a team of Korean researchers studied the effects of black soya in 32 rats.

The researchers allowed the rodents to gorge on a fatty diet supplemented with various levels of black soya.

After two weeks, the rats getting 10 percent of their energy from black soya gained half as much weight as those in the control group, and their total blood cholesterol and LDL (so-called "bad") cholesterol fell by 25 percent and 10 percent, respectively.

According to David Bender, sub-dean at the Royal Free and University College Medical School in London, soya protein may reduce the production of new fatty acids and cholesterol by affecting fat metabolism in the liver and adipose tissue. This may help explain why black soya is a traditional Asian treatment against diabetes.

"The key problem in type 2 diabetes is impairment of insulin action, mainly as a result of excess abdominal adipose tissue -- so loss of weight often improves glycemic control," said Bender in a prepared statement.

More information
The U.S. National Institute of Diabetes and Digestive and Kidney Diseases has more about diabetes.

Resistance to Hormone Leptin Called Key to Obesity

(HealthDay News) -- Researchers may have uncovered the biochemical defect that underlies food-induced obesity in mice.

Assuming it can be duplicated in humans, the finding suggests several potential anti-obesity drug targets, experts said.

Michael Cowley, of the Oregon National Primate Research Center at Oregon Health and Science University, led the study, which examined the cause of leptin resistance in diet-induced obese mice.

Leptin is a hormone, secreted by fat cells, which indicates how much fat is in the body and regulates food intake by binding to neurons in the hypothalamus region of the brain. In lean people, leptin serves to regulate weight by controlling appetite and the use of stored energy.

Obese individuals, however, appear to be resistant to leptin, much as diabetics are resistant to insulin.

The question was, what is the mechanism driving leptin resistance.

In the study, genetically identical mice were fed a high-fat diet for 20 weeks, at which point about 65 percent were obese. (That's a finding that Cowley said highlights the importance of epigenetics -- genetic differences not coded in DNA itself -- in obesity).

By comparing the obese animals to their lean littermates, as well as to control mice fed a normal diet, the researchers found that leptin normally governs neuropeptide release from cells called neurons in the hypothalamus, suppressing food intake and controlling energy utilization. In animals made obese by diet, however, leptin failed to trigger any response in these cells.

"We knew these cells were leptin-sensitive already," Cowley said. "The interesting finding was that they become non-responsive. We've identified the site of leptin resistance."

The study is published in the March 2007 issue of Cell Metabolism.

Dr. Julio Licinio, chairman of the department of psychiatry and behavioral sciences at the University of Miami Miller School of Medicine, who was not involved in the research, praised the study, calling it "very rigorous and sophisticated."

Licinio cited two interesting implications of the research. The first is that, in mice at least, leptin resistance is what he calls "functional," not permanent, and can be corrected by diet-induced weight loss.

Said Cowley: "If we put the obese animals on a low-fat diet, they recover from leptin resistance and drop weight. And when they recover, all the circuitry responses return to normal. We don't know if humans would respond in the same way, but we know that weight loss in humans is beneficial, even if you don't hit the ideal target weight."

Licinio also said the study suggests potential targets for drug development to fight excess weight. But, he added, "What the paper does not show is how resistance occurs and how you can overcome it."

One interesting facet of the findings, Cowley said, is the recognition that obesity, like diabetes, is truly a physical disease. "Obesity is not just a failure of will," he said. "This is a fundamental biological difference between obese and lean groups."

Licino said: "I think the take-home message is that (this study) gives hope. You need the caveat that it's not the same between mice and humans, but it does give hope that loss of a person's (ability) to regulate what they eat can be restored to maintain a normal weight."

More information
For more information on obesity, visit the U.S. Centers for Disease Control and Prevention.

Grocery Lists Don't Guarantee Healthy Choices

(HealthDay News) -- The grocery lists most people jot down before going to the store can create a mental loophole for impulse food.

That's because the act of remembering a variety of food choices makes people more vulnerable to slipping cookies, chips and other not-so-healthy items onto the list, a new study finds.

"The mental effort that you're using is mental effort you do not have to keep yourself in check -- controlling your desire for chocolate cake rather than fruit salad, for example," explained lead researcher Yuval Rottenstreich, an associate professor of management at Duke University.

Rottenstreich stressed, however, that it was still smarter to head to the supermarket with a list in hand than without -- just read it back and cross out any sugary or fatty items that may have snuck in.

The study is published in the March issue of the Journal of Consumer Research.

For years, nutritionists have urged dieters to draw up healthy, calorie-conscious shopping lists before they head out to the supermarket. "Not having that security of a shopping list ahead of time could actually be quite negative, especially if the person is going through the supermarket hungry," said Bonnie Taub-Dix, a New York City-based registered dietitian and spokeswoman for the American Dietetic Association.

The advice makes intuitive sense, but Rottenstreich and his co-researchers wanted to test whether it was foolproof in keeping folks true to their goals.

In three separate experiments, college students were asked to make consumer choices based on two real-life paradigms: "stimulus-based" decision-making, where the objects to choose from were right in front of the student (as would happen in a supermarket), and "memory-based" decision-making, where the students were asked to list the things they wanted to buy by drawing on their memory.

Lists didn't perform quite as well as expected.

In one experiment centered on a choice of four desserts -- chocolate cake, cheesecake, creme, and fruit salad -- the participants chose the healthier fruit salad far more when the four items were presented to them than when asked to recall the desserts from memory and then list their preference.

According to Rottenstreich, "This points out that making a list from memory does have a bit of a downside." The finding, he said, can be explained by neurology: The human brain does not have the capacity to activate both working memory and a full complement of rational impulse-control at once.

"So, if I am spending mental effort formulating my list, then that is mental effort I do not have in terms of making sensible choices," said Rottenstreich, who helped conduct the study while at New York University. In those situations, choices become more emotional, so tempting (but calorie-rich) "mistakes" can slip in.

But that doesn't mean dieters should throw out their grocery lists.

"I'd say that lists do work, in lots of ways. We're just aware now that there are trade-offs," Rottenstreich said. The simple act of re-reading your grocery list and crossing out any high-fat, high-sugar items can eliminate the problem, he added.

Taub-Dix agreed that drawing up a grocery list is a great way to keep unhealthy foods out of the home. She has even come up with a means of streamlining the process that's less taxing on the memory.
"I actually have a master list that I have typed out that's more or less the layout of my supermarket," she said. "On it, I will put all my fresh fruits and vegetables listed first, then the deli, etcetera. Then I just print it out and circle what I need. It makes shopping so much easier."

Another tip: Try and stick, whenever possible, to the supermarket's outside perimeter. "That's where the fresh produce, fruits and vegetables, the dairy aisle, chicken and lean meats usually are," Taub-Dix said.

And don't ever shop when you're hungry.

"We know that when you are too hungry, it's like being too tired or too drunk," she said. "What comes from that is apathy -- 'Whatever, I'm just going to take this.' "

A separate study, published in the same issue of the journal, suggests that the human mind finds other ways to get around self-control. In some cases, suppressing one area of mental or behavioral activity spurs an excess of activity in another area, such as spending.

In the study, researchers at the University of Minnesota asked half of the participants to perform a mental task but to not think of a "white bear." Then they gave the participants $10 to spend at a bookstore. The shoppers could keep any unspent money for themselves.

The result: People who had tried to stop themselves from thinking about the "white bear" spent an average of $4.05 -- nearly three times as much ($1.21) as participants who were put under no such constraint.

The finding may have lessons for people who embark on regimens involving self-denial, the researchers said. Perhaps, they wrote, "people should avoid shopping on days when they have earlier exercised great self-control or when starting a new self-improvement program, such as a new diet."

More information
There's more on healthy eating at the American Dietetic Association.

Americans Not Eating Enough Fruits and Veggies

(HealthDay News) -- Most Americans are still not eating the recommended amounts of fruits and vegetables, a new government report shows.

Even though many people know that fruits and vegetables help lower the risk of many diseases, consumption is still a long way from reaching the government goals set in Healthy People 2010, the researchers said. Their bad news is delivered in this week's issue of Morbidity and Mortality Weekly Report, a publication of the U.S. Centers for Disease Control and Prevention.

"Only 32.6 percent of adults are eating fruit two or more times per day, and only 27.2 percent are eating vegetables three or more times a day," said researcher Dr. Larry Cohen, an epidemic intelligence officer at the CDC.

That falls far short of the national goal of getting 75 percent of the population to eat fruit two or more times a day and 50 percent to eat vegetables three or more times per day by 2010, Cohen said.

The irony is that most Americans are aware of the benefits of eating fruits and vegetables, Cohen said. "However, translating that awareness to actually doing it is lacking."

To get closer to meeting these goals, a vigorous effort is needed to reach out to the public, Cohen said. "We need more measures to educate and motivate people to make healthier dietary choices," he said. "We have to target the family, the community and the overall society, and push policies that have a broad impact."

The data for the report were gathered using the Behavioral Risk Factor Surveillance System from 2005. The Behavioral Risk Factor Surveillance System is a survey of people throughout the United States. As part of the survey, people were asked how many servings of fruits and vegetables they ate per day.

Cohen thinks that there are a number of reasons that people aren't eating fruits and vegetables in greater numbers. "It could be due to lack of access, or that some people don't like fruits and vegetables. There could also be cultural reasons," he said.

One expert agrees that an effort to get more people to eat fruits and vegetables is important.
"The new CDC report indicates something we've long known, that fruits and vegetable intake is well below recommended levels," said Dr. David Katz, director of the Prevention Research Center at Yale University School of Medicine.

This is regrettable, Katz said. "These two food categories have the greatest potential of all for promoting health and fighting disease," he said.

Katz thinks that the problem is made worse by the food choices available to most Americans.
"The problem is compounded by price incentives and disincentives that encourage people to eat highly processed foods," Katz said. "It may also be compounded by the popularity of low-carb diets that discourage people from eating fruit."

Katz thinks eating a healthful diet should be a national priority. "There needs to be an effort to find ways to get more people to eat fruits and vegetables and to convince them that it's important for health," he said.

More information
For more information on a healthful diet, visit the U.S. Department of Health and Human Services.