Cutting down on sugar has a small but significant effect on body weight

And should be part of strategy to reduce high levels of overweight and obesity

Reducing sugar intake has a small but significant effect on body weight in adults, finds a paper published on bmj.com January 15, 2013.

Although the effect is relatively small (an average reduction of 0.8 kg), the findings provide some support for international guidelines to cut sugar intake to less than 10% of total energy to help reduce the global obesity epidemic.

Excessive sugar in the diet has been linked to obesity, and a higher risk of chronic diseases. The most consistent association has been between a high intake of sugar sweetened beverages and the development of obesity, but not all studies have reported a statistically significant link.

The World Health Organization has suggested that intake of "free sugars" should be less than 10% of total energy intake, but no upper safe limit has been agreed. So a team of researchers at the University of Otago and the Riddet Institute in New Zealand analysed the results of 71 studies (30 randomised controlled trials and 41 cohort studies) of sugar intake and body fatness to summarise evidence on the association between intake of dietary sugars and body weight in both adults and children.

Free sugars were defined as sugars that are added to foods by the manufacturer, cook, or consumer; plus those naturally present in honey, syrups, and fruit juices. Differences in study design and quality were taken into account to minimise bias.

They found that advice to reduce free sugars was associated with an average 0.8 kg reduction in weight (in studies that ran for up to 8 months), while advice to increase intake was associated with a corresponding 0.75 kg increase.

This parallel effect, they suggest, seems be due to an altered energy intake, since replacing sugars with other carbohydrates did not result in any change in body weight.

The evidence was also less consistent in children, mainly due to poor compliance to dietary advice. However, for sugar sweetened beverages, the risk of being overweight or obese increased among children with the highest intake compared with those with the lowest intake.

The authors say that, given the many causes of obesity, it is unsurprising that the effect of reducing intake is relatively small, and they point out that some other unmeasured (confounding) factors may explain some or all of this effect. But they add "the overall consistency of the findings, regardless of study type, is reassuring."

They also acknowledge that the extent to which population based advice to reduce sugars might reduce risk of obesity "cannot be extrapolated from the present findings, because few data from the studies lasted longer than ten weeks." But conclude that "when considering the rapid weight gain that occurs after an increased intake of sugars, it seems reasonable to conclude that advice relating to sugars intake is a relevant component of a strategy to reduce the high risk of overweight and obesity in most countries."

In an accompanying editorial, US experts say the association between sugar and poor health has remained contentious over the past few decades, but that accumulating evidence "points towards a role for sugar and other refined carbohydrates in the development of overweight."

They say reducing the intake of sugar sweetened drinks "is a high priority" and point to policies such as taxes on sugar laden drinks, restrictions on advertising to children, and limits on serving sizes. They also call for action at many levels, including educational programs, improvements in foods and drinks in schools and worksites, and nutrition programs for people with low incomes.

Finally, a feature comments on the 40th anniversary of the publication of the popular book – Pure, White and Deadly – written by the British physiologist John Yudkin, which claimed that high sugar consumption was associated with heart disease.

It considers new evidence linking fructose (found in nearly all added sugars) with insulin resistance - a pre-cursor of heart disease – and suggests that Yudkin's warnings are finally being recognised, despite ongoing opposition from the sugar industry.

Black Pepper Fights Fat

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A new study provides a long-sought explanation for the beneficial fat-fighting effects of black pepper. The research, published in ACS' Journal of Agricultural and Food Chemistry, pinpoints piperine - the pungent-tasting substance that gives black pepper its characteristic taste, concluding that piperine also can block the formation of new fat cells.

Soo-Jong Um, Ji-Cheon Jeong and colleagues describe previous studies indicating that piperine reduces fat levels in the bloodstream and has other beneficial health effects. Black pepper and the black pepper plant, they note, have been used for centuries in traditional Eastern medicine to treat gastrointestinal distress, pain, inflammation and other disorders. Despite that long medicinal history, scientists know little about how piperine works on the innermost molecular level. The scientists set out to get that information about piperine's anti-fat effects.

Their laboratory studies and computer models found that piperine interferes with the activity of genes that control the formation of new fat cells. In doing so, piperine may also set off a metabolic chain reaction that helps keep fat in check in other ways. The group suggests that the finding may lead to wider use of piperine or black-pepper extracts in fighting obesity and related diseases.

Artificial Sweeteners Aid Weight Loss if Used Appropriately".

Artificial sweeteners, also known as non-nutritive sweeteners, may help people reach their body weight goal, and also maintain a healthy body weight, researchers reported in two journals, Circulation and Diabetes Care. However, users have to make sure they do not "compensate" by eating high-calorie foods. An example of "compensating" might be ordering a diet coke and also a large slice of chocolate cake.

Non-nutritive sweeteners are also known as low-calorie sweeteners, artificial sweeteners, non-caloric sweetners, and intense sweeteners.

The American Diabetes Association stated that for diabetes patients, using artificial sweeteners on their own or in foods and drinks may help aid glucose control if "used appropriately".

In a new scientific statement issued by the American Diabetes Association and the American Heart Association, replacing added sugars in drinks and other foods with non-nutritive sweeteners can, if used appropriately, help people lose weight and keep it off.

However, according to the article in Circulation, there is limited compelling scientific evidence that using artificial sweeteners is effective in the long-term for reducing calorie intake and consuming fewer added sugars.

The American Heart Association (AHA) states that a high dietary sugar intake is a contributory factor for obesity, cardiovascular disease, and developing type 2 diabetes. Added sugar consumption should not exceed 100 calories per day for women and 150 calories for men, if the consumer does not wish to increase the risk of the diseases and conditions mentioned above, the AHA adds.


McDonald's Royal Pattaya meal 20110513
Experts say "Do not compensate" - Do not have a diet drink together with a high-calorie meal


Another problem with sugary foods and drinks is that they displace nutritious food consumption, which may not only lead to weight gain, but also some level of malnutrition - i.e. the person may not be consuming the right balance of vitamins, minerals, fiber and proteins for good health.

Christopher Gardner, Ph.D., associate professor of medicine at Stanford University in California, said:

"While they are not magic bullets, smart use of non-nutritive sweeteners could help you reduce added sugars in your diet, therefore lowering the number of calories you eat. Reducing calories could help you attain and maintain a healthy body weight, and thereby lower your risk of heart disease and diabetes. But there are caveats."



Examples of non-nutritive sweeteners quoted by the authors include:

* aspartame
* acesulfame-K
* neotame
* saccharin
* sucralose
* plant-derived stevia

Most studies on artificial sweeteners are inconclusive
The authors explained that to date, studies on whether artificial sweeteners used to displace calorie-rich sweeteners, such as added sugars, may result in a reduction in carbohydrate consumption (desirable for diabetes control), calorie consumption, body weight control are inconclusive. Studies are also inconclusive regarding artificial sweeteners' long-term impact on appetite, and the reduction of other risk factors linked to heart disease and diabetes.

Dr. Garner said:"Determining the potential benefits from non-nutritive sweeteners is complicated and depends on where foods or drinks containing them fit within the context of everything you eat during the day. For example, if you choose a beverage sweetened with non-nutritive sweeteners instead of a 150-calorie soft drink, but then reward yourself with a 300-calorie slice of cake or cookies later in the day, non-nutritive sweeteners are not going to help you control your weight because you added more calories to your day than you subtracted. However, if you substitute the beverage with non-nutritive sweeteners for a 150-calorie sugar-sweetened soft drink, and don't compensate with additional calories, that substitution could help you manage your weight because you would be eating fewer calories. "

For people with diabetes, soft drinks with artificial sweeteners do not raise blood glucose levels, and can therefore provide patients with a "sweet option", says the American Diabetes Association. However, people need to select carefully; just because something says it has artificial sweeteners instead of sugar does not necessarily mean it is a "free" food or a healthy one.

Diane Reader, R.D., CDE, manager of professional training at the International Diabetes Center in Minneapolis, Minn., said: "The use of non-nutritive sweeteners may be used in a carbohydrate-controlled food plan, to potentially reduce carbohydrate intake which may aid in weight management and diabetes control."

The American Heart Association and the American Diabetes Association both stressed that their new statement on artificial sweeteners does not evaluate the safety of such ingredients; this is done by the FDA (Food and Drug Administration).

Garner said:"For anyone trying to monitor or reduce their intake of calories or added sugars, the potential impact of choosing 'diet products' with non-nutritive sweeteners needs to be considered within the context of the overall diet. Strategies for reducing calories and added sugars also involves choosing foods which have no added sugars or non-nutritive sweeteners - such as vegetables, fruits, high-fiber whole grains, and non or low-fat dairy."

Self-Control, Willpower Improved By Paying More Attention To Quantity Eaten

New research from the University of Minnesota's Carlson School of Management suggests learning how to stop enjoying unhealthy food sooner may play a pivotal role in combating America's obesity problem. The research, published in the Journal of Consumer Research, explores how satiation, defined as the drop in liking during repeated consumption, can be a positive mechanism when it lowers the desire for unhealthy foods.

"When people talk about self-control, they really imply that self-control is willpower and that some people have it and others don't when facing a tempting treat," says Joseph Redden, an assistant professor of marketing at the Carlson School and lead author of the 'Healthy Satiation: The Role of Decreasing Desire in Effective Self-Control.' "In reality, nearly everyone likes these treats. Some people just stop enjoying them faster and for them it's easier to say no."

Through a series of experiments, Redden and Texas A&M University assistant professor of marketing Kelly Haws discovered that when people with high self-control eat unhealthy foods they become satisfied with the experience faster than when they are eating healthy foods and thus eat less. In one study, the researchers asked participants to monitor themselves as they ate by counting how many times they swallowed. With this subtle clue to the amount eaten, those with low self-control became satisfied at a faster rate. Redden said they were surprised at how easy it was to recreate self-control - just using a baseball pitch counter made low self-control people act like they had high self-control.

"People can essentially use attention for how much they are consuming instead of relying on self-control," Redden says. "Really paying a lot more attention to the quantity will lead people to feel satiated faster and eat less."

Effective Weight Loss - Keep A Food Journal, Don't Skip Meals, Don't Eat Out

If you want to really succeed in losing weight you should never skip meals, you should avoid eating out, and ideally, you should keep a food journal, especially if you are an overweight or obese postmenopausal woman, researchers from the Fred Hutchinson Cancer Research Center reported in the Journal of the Academy of Nutrition and Dietetics. The authors added that eating out in restaurants during lunchtime especially, should be avoided.

The authors claim that theirs is the first study ever to focus on the impact of a wide list of self-monitoring options and diet-related behaviors, as well as eating patterns on body weight among obese and overweight postmenopausal females.

Anne McTiernan, M.D., Ph.D., team leader, said: "When it comes to weight loss, evidence from randomized, controlled trials comparing different diets finds that restricting total calories is more important than diet composition such as low-fat versus low-carbohydrate.

Therefore, the specific aim of our study was to identify behaviors that supported the global goal of calorie reduction."

Below are some of their findings:

* Food journals - those who kept food journals, across all diets, lost approximately 6 pounds more than women who did not
* Missing meals - the females who "skipped meals" lost much less weight than those who never missed meals, about 8 pounds less
* Lunching out - women who went out for lunch at least once a week lost about 5 fewer pounds compared to those who lunched out less often. Eating out regularly for breakfast, lunch or supper was linked to less weight loss; however, the strongest association was with lunch.

Food journals

McTiernan said: "For individuals who are trying to lose weight, the No. 1 piece of advice based on these study results would be to keep a food journal to help meet daily calorie goals. It is difficult to make changes to your diet when you are not paying close attention to what you are eating."

When keeping a food journal, the researchers advised those participating in the study to:

* Be thorough - make sure the journal has details of food preparation, which toppings, condiments, sauces or gravy were used, etc.
* Be truthful - make sure everything that is eaten is recorded, do not leave anything out
* Accuracy - portion sizes, label details, need to be accurately entered
* Consistency - the food journal (diary) must be with the dieter at all times; this is easier these days with some of the applications for smart phones

McTiernan said:"While the study provided a printed booklet for the women to record their food and beverage consumption, a food journal doesn't have to be anything fancy. Any notebook or pad of paper that is easily carried or an online program that can be accessed any time through a smart phone or tablet should work fine."

Missing meals

For successful weight loss, the researchers found that eating at regular intervals is vital for effective and long-term weight loss. Skipping meals can be a diet's kiss of death.

McTiernan explained:"The mechanism is not completely clear, but we think that skipping meals or fasting might cause you to respond more favorably to high-calorie foods and therefore take in more calories overall. We also think skipping meals might cluster together with other behaviors. For instance, the lack of time and effort spent on planning and preparing meals may lead a person to skip meals and/or eat out more."

Lunching out

Eating out was found to undermine the overall success of weight loss efforts, when compared with rarely or never eating out, the authors wrote. Going out to restaurants may be an obstacle for making healthful food choices, they added.

When we are at a restaurant we have less control in what ingredients are used in preparing our meals, and which cooking methods are used. Even portion sizes are no longer under our control.

The study involved 123 women aged from 50 to 75 years. They were all overweight or obese and lived sedentary lifestyles. They were selected at random into two groups in this year-long dietary weight loss intervention study:

* Exercise plus diet group
* Diet only group

They completed questionnaires which asked them about their dietary intake, what eating-related weight-control strategies they used, meal patterns, and eating behaviors. In order to assess what changes occurred from the beginning to the end of the study, they completed a 120-item food-frequency questionnaire.

Participants in both groups weighed on average 10% less than they did at the start of the study - the aim of the intervention was also a 10% drop from starting weight.

McTiernan said: "We think our findings are promising because it shows that basic strategies such as maintaining food journals, eating out less often and eating at regular intervals are simple tools that postmenopausal women - a group commonly at greater risk for weight gain - can use to help them lose weight successfully."

In an Abstract in the same journal, the authors believe their findings indicate that more focus should be placed on dietary self-monitoring, home cooking, and a regular eating routine for a more effective 12-month weight-loss regime among women over the age of 50 years.

Food In Smaller Pieces May Help Control Weight

Cutting up food into smaller pieces may help people control their weight more easily because they are more satisfying to eat than one large piece with the same number of calories, according to a new study presented at a conference this week.

The 2012 meeting of the Society for the Study of Ingestive Behavior in Zurich, Switzerland, heard how the researchers concluded that humans, like animals, seem to find eating food as smaller pieces more enjoyable and satisfying.

In a press release issued on Tuesday, lead author Devina Wadhera, from the Department of Psychology at Arizona State University in the US, suggests:

"Cutting up energy-dense meal foods into smaller pieces may be beneficial to dieters who wish to make their meal more satiating while also maintaining portion control."

Previous studies have already suggested that larger portions lead people to eat more. For this study, Wadhera and colleagues focused on the number and size of food pieces, because it is also known that humans and other animals judge food quantity using several cues, of which number is one, with larger numbers usually taken to mean larger amounts.

For instance, in 1989, a team of researchers ran a series of intriguing experiments with rats in mazes. In the first experiment they trained rats in a T-maze using 4 x 75 mg food pellets in one arm of the T, and a single 300 mg pellet in the other arm.

The rats developed a preference for the 4 x 75 mg arm, and when the researchers reversed the arms, the rats also switched their preference. This indicated, when faced with the same weight of food, the rats preferred the four-pellet alternative to the single pellet one.

In a slightly different version of the experiment, the researchers put 4 x 45 mg pellets in one arm and a single 300 mg pellet in the other. But this time the rats showed a preference for the 300 mg arm, indicating they were choosing weight over number of pieces. This was confirmed in a third experiment, when the choice was either 4 x 45 mg, or 4 x 75 mg pellets.

The researchers in that study concluded that rats prefer multiple to single food units, and judge a given weight of food as greater when the number of units is greater. They proposed that this apparent "failure of conservation" may be common to other species, including humans.

So to test the idea in humans, Wadhera and colleagues invited 301 college students to take part in an experiment where they gave each an 82 g bagel, either uncut or cut into four.

Twenty minutes after eating the bagel, the students were invited to eat as much as they wanted from a measured amount of food at a free lunch (the test meal).

Any left over bagel or test meal was then measured to assess what each student had eaten.

The results showed that the students who ate the single, uncut bagel, ate more calories from both the bagel and the test meal, than their fellow counterparts who were given the bagel as four pieces.

Wadhera said this showed that eating food cut into several pieces may be more satiating than eating it as a single, uncut portion.

The idea of manipulating perception to fool the body about food, was also taken up in another study reported in February 2012, where researchers from the Netherlands found that manipulating the aroma of food caused people to take smaller bites, resulting in up to 10% reduction in intake per bite. They suggested aroma control combined with portion control could fool the body into thinking it was full with a smaller amount of food.

30 Minutes Of Daily Exercise As Good As 60 For Weight Loss

A new study from the University of Copenhagen in Denmark found that sedentary, slightly overweight healthy young men who worked up a sweat exercising 30 minutes daily for three months lost a similar amount of weight and body fat as those who did 60 minutes of daily exercise.

The researchers describe the findings of their randomized controlled trial in a study reported online recently in the American Journal of Physiology.

The researchers suggest one reason for the surprising result is that the exercise felt "doable" for the participants in the 30 minutes a day group, who even felt afterwards that they could have done more. Whereas in the 60 minutes a day group, they probably compensated by eating more, therefore losing less weight than expected.

This second point would fit in with the results of previous research that the researchers point to in their background information. This suggests that the reason exercise often produces a disappointing amount of weight loss is because a diet-induced negative energy balance (where calories consumed aren't enough to cover daily energy needs) often triggers "compensatory mechanisms", such as lower metabolic rate and increased appetite.

Perhaps 60 minutes of exercise results in more overcompensation than 30 minutes.

On average, the men who exercised 30 minutes a day lost 3.6 kg in three months, and those who exercised 60 minutes a day lost 2.7 kg. The reduction in body fat was about 4 kg for both groups.

The result is significant because 40% of Danish men are thought to be moderately overweight. Overcoming barriers to exercise in a group that does none at all, should be easier if the aim is to attain 30 minutes a day than 60 minutes a day.

The study is part of an interdisciplinary trial called FINE, a a Danish acronym for Physical Activity for a Long Healthy Life, which has generated strong data in a group of 60 or so participants.

Running at the gym
Researchers suggest that 30 minutes of exercise hard enough to cause a sweat produces as much loss in body weight and fat as a whole hour.
In FINE, the participants were followed by health scientists who focused on energy balance, insulin resistance and hormones in the blood.

Ethnologists were also part of the FINE research team: they were interested in exploring the barriers to exercise and in helping the participants overcome entrenched cultural habits.

For the study, the researchers randomly assigned each of 62 healthy, sedentary, moderately overweight young men to one of three groups: a high exercise group (burning about 600 kcal per day with about 60 minutes of aerobic exercise), a moderate exercise group (300 kcal per day, 30 minutes exercise), and a control group that continued to be sedentary.

They monitored the men as they followed their program for 13 weeks.

The participants trained every day through the study period. The training sessions were planned to produce a light sweat, but the participants were also instructed to increase the intensity three times a week.

The results showed that body weight went down by 2.7 kg in the high exercise group, and 3.6 kg in the moderate exercise group. Fat mass went down by 4.0 kg and 3.8 kg respectively.

But what was very surprising was although the energy burned during exercise in the high exercise group was double that of the moderate exercise group, they had roughly the same accumulated energy balance.

Energy balance is the balance of calories consumed through eating and drinking compared to calories burned through physical activity.

In this study, the researchers calculated it from changes in body composition.

The results showed that the accumulated energy balance was 83% more negative than expected in the moderate exercise group (ie better than expected), and 20% less negative than expected in the high exercise group (ie worse than expected).

"No statistically significant changes were found in energy intake or non-exercise physical activity that could explain the different compensatory responses associated with 30 vs. 60 min of daily aerobic exercise," write the researchers, who conclude:

"... a similar body fat loss was obtained regardless of exercise dose. A moderate dose of exercise induced a markedly greater than expected negative energy balance, while a higher dose induced a small but quantifiable degree of compensation."

First author Mads Rosenkilde, a PhD student in the Department of Biomedical Sciences, told the press:

"Participants exercising 30 minutes per day burned more calories than they should relative to the training program we set for them. In fact we can see that exercising for a whole hour instead of a half does not provide any additional loss in either body weight or fat."

"The men who exercised the most lost too little relative to the energy they burned by running, biking or rowing. 30 minutes of concentrated exercise give equally good results on the scale," he added.

Rosenkilde said they were surprised by the results, and the team now wants to study the effect of other forms of exercise.

He would like to explore ways of building exercise into daily life, for instance as a form of transport:

"Training is fantastic for your physical and mental health. The problem is that it takes time. If we can get people to exercise along the way - to work, for example - we will have won half the battle," said Rosenkilde.

Providing Non-Caloric Beverages To Teens Can Help Them Avoid Excessive Weight Gain

A new study published in the New England Journal of Medicine shows that adolescents who eliminated sugar-sweetened beverages for one year gained less weight than those who didn't, shedding light on an effective intervention to help combat adolescent obesity.

This is one of the first high-quality randomized control trials to examine the link between the consumption of sugar-sweetened beverages and their direct impact on weight and body mass index (BMI), as well as how a teen's home environment impacts sugar-sweetened beverage consumption in general.

The study, led by Cara Ebbeling, PhD (associate director) and David Ludwig, MD, PhD (director), both from the New Balance Foundation Obesity Prevention Center Boston Children's Hospital, found that adolescents who received deliveries of non-caloric beverages for one year gained an average of 4 fewer pounds than their peers who continued to drink sugar-sweetened beverages. Within the two-year study, the one-year intervention also included motivational calls with parents, check-in visits with participants and written intervention messages to stop drinking sugar-sweetened beverages.

The 224 study participants were overweight or obese 9th or 10th graders who regularly drank sugary beverages. The study intervention was designed to reduce consumption of these beverages. Researchers used a novel method of intervention: delivering non-caloric beverages to participants' homes for participants and their families.

During the year-long intervention, the experimental group of adolescents - who virtually eliminated consumption of sugary beverages - gained 4 fewer pounds and had essentially no BMI increase compared to the control group, which continued to drink sugar-sweetened beverages regularly (although at reduced levels possibly due to local public health efforts). In addition, Hispanic adolescents showed the greatest benefit - gaining 14 fewer pounds than the control group. "No other single food product has been shown to change body weight by this amount over a year simply through its reduction," says Ludwig.

The two-year study consisted of one year of intervention and one year of follow up. While the one-year mark showed a significant difference in weight between the intervention group and the control group, the groups did not differ after the second year - which did not include an intervention. These findings suggest that teens are more likely to make healthier choices (drinking non-caloric beverages) when they are more easily available to them.

This study underscores the need for healthy choices to be more easily available to adolescents, as well as the need for more research into effective interventions among minority populations with particularly high obesity rates. "Our findings suggest that both access to non-caloric beverages and clear messages for consumers may be at the heart of behavior change. Adolescents can make healthful dietary changes with adequate support and understandable messages," says Ebbeling.

The study is part of a series in the New England Journal of Medicine that looks at the association between sugar-sweetened beverages and obesity.

The Center recently published another study in the Journal of the American Medical Association by the New Balance Foundation Obesity Prevention Center Boston Children's Hospital suggesting that conventional low-fat diets may not be the best for weight-loss maintenance, and that reducing intake of refined carbohydrates (so called, low-glycemic diets) provide metabolic benefits and reduced risk of heart disease.

Exercise and healthy eating reduce body fat and preserve muscle in adults better than diet alone

Exercise and healthy eating reduce body fat and preserve muscle in adults better than diet alone, according to a study funded and conducted by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. The study was recently published online in Obesity and will be in a future print edition.

NIDDK senior investigator Kevin Hall, Ph.D., analyzed the individual effects of daily strenuous exercise and a restricted diet by examining data from 11 participants from the reality television program "The Biggest Loser." The program shows obese adults losing large amounts of weight over several months. Participants were initially isolated on a ranch followed by an extended period at home.

"By including the show's contestants as voluntary study participants, this research took advantage of a cost-efficient opportunity to study a small group of obese individuals already engaged in an intensive lifestyle intervention," said Hall, who has no financial ties and no other affiliation to the show.

Researchers measured body fat, total energy expenditure and resting metabolic rate - the energy burned during inactivity - three times: at the start of the program, at week 6, and at week 30, which was at least 17 weeks after participants returned home. Participation in the program led to an average weight loss of 128 pounds, with about 82 percent of that coming from body fat, and the rest from lean tissue like muscle. Preserving lean tissue, even during rapid and substantial weight loss, helps maintain strength and mobility and reduces risk of injury, among other benefits.

Hall used a mathematical computer model of human metabolism - currently intended for research conducted by scientists and health professionals - to calculate the diet and exercise changes underlying the observed body weight loss. Because the TV program was not designed to directly address how the exercise and diet interventions each contributed to the weight loss, the computer model simulated the results of diet alone and exercise alone to estimate their relative contributions.

At the competition's end, diet alone was calculated to be responsible for more weight loss than exercise, with 65 percent of the weight loss consisting of body fat and 35 percent consisting of lean mass like muscle. In contrast, the model calculated that exercise alone resulted in participants losing only fat, and no muscle. The simulation of exercise alone also estimated a small increase in lean mass despite overall weight loss.

The simulations also suggest that the participants could sustain their weight loss and avoid weight regain by adopting more moderate lifestyle changes - like 20 minutes of daily vigorous exercise and a 20 percent calorie restriction - than those demonstrated on the television program.

More than two-thirds of U.S. adults age 20 and older are overweight or obese, and more than one-third of adults are obese. Excess weight can lead to type 2 diabetes, heart disease, high blood pressure, stroke, and certain cancers.

"This study reinforces the need for a healthy diet and exercise in our daily lives," said NIDDK Director Dr. Griffin P. Rodgers. "It also illustrates how the science of metabolism and mathematical modeling can be used to develop sound recommendations for sustainable weight loss - an important tool in the treatment of obesity - based on an individual's unique circumstances."

Skipping Breakfast Increases Appeal Of High Calorie Foods

Scientists presenting a new study at a conference suggest the reason skipping breakfast makes high calorie food more appealing later in the day is because our brain circuits may be primed toward seeking it when fasting.

Lead author of the study, Tony Goldstone of Imperial College London in the UK, and colleagues, compared people's MRI brain scans and their eating patterns, both after breakfast and when they skipped it.

They presented their findings at Neuroscience 2012 in New Orleans. Goldstone, who is from Imperial's MRC Clinical Science Centre, told the press:

"Through both the participants' MRI results and observations of how much they ate at lunch, we found ample evidence that fasting made people hungrier, and increased the appeal of high-calorie foods and the amount people ate."

For their study, the team took several functional magnetic resonance images (fMRIs) of 21 normal-weight volunteers who were asked not to have any breakfast when they arrived in the test centre on the mornings of their visits.

After an initial visit, some days the participants ate a large 750-calorie breakfast about one and a half hours before undergoing scans, while on other days they underwent scanning without receiving a breakfast beforehand. They were served lunch after the scans each time, and the scientists observed how much they ate.

On each occasion, participants were also asked to rate the appeal of pictures of high-calorie and low-calorie foods while they underwent brain scanning. They were also asked to rate the appeal of household objects as a control.

The results showed that skipping breakfast increased hunger, appeal of high-calorie foods and food intake at lunch after scanning.

When they compared the brain scans of the breakfast eating and the breakfast skipping visits, the researchers noticed different patterns of activity in the orbitofrontal cortex. This area is situated just above the eyes and influences judgements about pleasantness and reward value of food.

On the days the participants skipped breakfast, this area was more active when they looked at pictures of high-calorie foods than on the day they had breakfast.

The study suggests the orbitofrontal cortex plays a key role in making food choices. The researchers say their findings add weight to previous studies that have suggested fasting is not a good way to lose weight: it appears to "bias" the brain toward seeking out high-calorie foods.

They said it was possible, through looking at the MRI scans, to predict which individuals were "primed" to respond more strongly to high-calorie food.

Funds from the UK Medical Research Council (MRC), the European Union Marie Curie Fellowship, Imperial College Healthcare Charity, and the National Institute for Health Research helped finance the study.

Get More Sleep to Lose Weight

Evidence linking partial sleep deprivation to energy imbalance is relevant to weight gain prevention and weight loss promotion. A new study published in the Journal of the Academy of Nutrition and Dietetics bases this finding on an extensive review of literature published over a fifteen-year period.

More than 35 percent of American adults are obese and more than 28 percent sleep less than six hours a night. While weight-loss strategies incorporate lifestyle changes focusing on diet and exercise, modifications in an individual's daily routine, including sleep behaviors, can help manage weight.

"Various investigations, although diverse, indicate an effect of partial sleep deprivation on body weight management," says lead investigator Sharon M. Nickols-Richardson, PhD, MD, professor, Department of Nutritional Sciences, The Pennsylvania State University, University Park. "The intriguing relationship between partial sleep deprivation and excess adiposity makes partial sleep deprivation a factor of interest in body weight regulation, particularly in weight loss."

The research team evaluated articles published between 1996 and 2011 to determine the role of partial sleep deprivation on energy balance and weight regulation. As part of its methodology, the team constructed a series of comparative tables detailing individual study populations, study designs, energy intake, energy expenditure, and measurements of the hormones ghrelin, leptin, insulin, glucose, and cortisol. Analysis of these characteristics identified a set of patterns, including reduced insulin sensitivity, increases in ghrelin, and decreases in leptin among partially sleep-deprived individuals. Changes in ghrelin and leptin influenced energy intake among the study populations.

"Changes in these hormones coinciding with an energy-reduced diet paired with changes in response to partial sleep deprivation may be expected to increase ghrelin and decrease leptin concentrations even further to promote hunger," says Dr. Nickols-Richardson.

The paper calls for further research to determine the effects of sleep deprivation on body composition and substrate use and suggests evaluation of an individual's sleep patterns combined with regular, sufficient sleep may benefit healthy weight management.

Group-Based Weight Loss Treatment Is Effective Whether Led By Health Professionals Or By Peer Counselors

A new National Institutes of Health (NIH)-funded study conducted at Baruch College and published in Obesity found that overweight and obese adults who participated in three different weight loss treatments, all involving intensive, multi-component counseling delivered in groups, lost significant weight after 48 weeks whether the treatment was led by a health professional or by someone who had previous weight loss success.

This randomized clinical trial led by Angela Marinilli Pinto, PhD Assistant Professor of Psychology at Baruch College, is the first to compare professionally delivered group-based behavioral weight loss treatment - considered the "gold standard" for treating moderate overweight and obesity- to Weight Watchers, which is led by trained peer counselors who have achieved their own successful weight loss. The findings open up the possibility of offering effective, affordable weight loss options to more Americans.

In this study, 141 overweight and obese men and women were randomly assigned to:

* 48 weeks of behavioral weight loss treatment delivered by a health professional,
* 48 weeks of Weight Watchers, where group support is led by Weight Watchers members who have successfully achieved and maintained a healthy goal weight,
* Or a combined treatment consisting of 12 weeks of behavioral weight loss treatment delivered by a health professional followed by 36 weeks of Weight Watchers.

Weight Watchers was chosen because it is the largest commercial program in the United States and is behaviorally oriented and focuses on modifying diet and increasing physical activity to produce weight loss. The investigators hypothesized that the combined treatment would produce better weight losses than Weight Watchers alone. Assessments were conducted at baseline and weeks 12, 24, and 48, with weight change as the primary outcome.

All groups lost weight, but contrary to expectations, Weight Watchers participants lost more weight, on average, at the end of treatment compared to participants in the combination approach (mean weight loss in the professionally led program was not significantly different from either group). In fact, 37% of Weight Watchers participants lost 10% or more of their starting weight compared to 15% of combined group participants and 11% of participants in the professionally led group.

Results of the study also showed that better meeting attendance was associated with greater weight losses during the first 24 weeks in all treatments. In the Weight Watchers group, this relationship was maintained even in the second half of treatment, suggesting that individuals who continue to stay involved in the Weight Watchers program do better.

"This study is important because, with almost 70% of American adults classified as overweight or obese, there is a need to provide practical treatment solutions that are effective, accessible, and affordable," Dr. Pinto explained. "Results of this study demonstrate that the Weight Watchers program can produce clinically meaningful weight losses." The cost of joining Weight Watchers is approximately $10 per week, which includes member registration, weekly meetings, and access to online resources.