New tool being studied to customize diet and exercise regimens to lose weight
Posted by on September 9, 2011 - 7:07am

A new simulation model predicts weight changes with varying diets and exercise plans.  Researchers at the National Institutes of Health (NIH) have created a mathematical model — and an accompanying online weight simulation tool — of what happens when people of varying weights, diets and exercise habits try to change their weight. The findings challenge the commonly held belief that eating 3,500 fewer calories — or burning them off exercising — will always result in a pound of weight loss.

Instead, the researchers’ computer simulations indicate that this assumption overestimates weight loss because it fails to account for how metabolism changes. The computer simulations show how these metabolic changes can significantly differ among people. Findings are published Aug. 26 in a Lancet issue devoted to obesity.

However, the computer simulation of metabolism is meant as a research tool and not as a weight-loss guide for the public. The computer program can run simulations for changes in calories or exercise that would never be recommended for healthy weight loss. The researchers hope to use the knowledge gained from developing the model and from clinical trials in people to refine the tool for everyone.

“This research helps us understand why one person may lose weight faster or slower than another, even when they eat the same diet and do the same exercise,” said Kevin Hall, Ph.D., an obesity researcher and physicist at the NIH, National Institute of Diabetes and Digestive and Kidney Disorders (NIDDK)  and the paper’s first author. “Our computer simulations can then be used to help design personalized weight management programs to address individual needs and goals.”

The online simulation tool based on the model enables researchers to accurately predict how body weight will change and how long it will likely take to reach weight goals based on a starting weight and estimated physical activity. The tool simulates how factors such as diet and exercise can alter metabolism over time and thereby lead to changes of weight and body fat.

To test the model, the researchers compared predicted weight changes to actual changes in people. For example, the team found that people’s bodies adapt slowly to changes in dietary intake. They also found heavier people can expect greater weight change with the same change in diet, though reaching a stable body weight will take them longer than people with less fat.

The model also points to a potential simplified method to approximate weight loss in an average overweight person. An adult who has a body mass index (a measure of a person’s weight in relation to his or her height) between 25 and 29.9 is considered overweight. One example: For every pound you want to lose, permanently cut 10 calories from your current intake per day. At that rate, it will take about one year to achieve half of the total weight loss, and almost all of the weight loss will have occurred by three years. This calculation shows how long it takes to achieve a weight-loss goal for a single permanent change of diet or exercise. Researchers can use the web simulation tool to plan for a phase of more-rapid weight loss followed by a weight maintenance phase. People should consult with their physician prior to embarking on a diet plan.

“This research illustrates how the interdisciplinary skills of NIH scientists, like a physicist doing obesity research, can help lead to innovative ways to test, understand and treat a major public health epidemic,” said NIDDK Director Griffin P. Rodgers, M.D. “Advancing research from the laboratory to the bedside enables us to make the discoveries that can better people’s lives.”

 

What you eat (not just how much) may affect muffin top bulge
Posted by on August 18, 2011 - 6:38am

Munching more unprocessed plant foods may help keep the middle-aged bulge away (AKA muffin top) , a new study suggests. On the other hand, meat, french fries and sugar-sweetened drinks can help pack on the pounds. The findings suggest that the types of food you choose, not just calories, are important for avoiding age-related weight gain.

Weight gain results from an imbalance between how much energy you take in and how much you expend. Even small amounts of excess weight can increase your risk for disorders such as diabetes, cardiovascular disease, metabolic syndrome and cancer.

A research team at the Harvard School of Public Health, led by Dr. Dariush Mozaffarian and Dr. Frank Hu, sought to gain insights into the changes in people’s lifestyles that lead to gradual, long-term weight gain.

The team followed the lifestyle and dietary habits of 3 large groups of health professionals, totaling over 120,000 people, for 12 to 20 years.

The researchers found several general lifestyle changes linked to weight gain over a 4-year period. Participants who increased their physical activity gained less weight than those who didn't. However, only increases in activity during the period studied produced this result; absolute levels of physical activity (across the lifespan) weren't associated with weight change. People who slept for less than 6 hours a day or more than 8 hours gained more weight. Increases in TV-watching led to an average gain of about a third of a pound for every hour of TV watching per day.

Food choices also affected weight. Potato chips, sugar-sweetened drinks, processed meats and unprocessed red meat were each linked to weight gain of about a pound or more. Eating more french fries led to an average gain of over 3 pounds. Eating more refined grains and sweets or desserts led to about half a pound of weight gain. By contrast, eating more vegetables, whole grains, fruits, nuts and yogurt was linked to reductions in weight over a 4-year period. Yogurt led the pack, with an average of 0.82 pounds of weight lost.

The researchers suggest that highly processed foods may not satisfy hunger as well as less processed, higher fiber foods, causing a higher total intake of calories. “The idea that there are no ‘good’ or ‘bad’ foods is a myth that needs to be debunked,” Hu says.

This was an observational study, in which people were asked to recall the foods they ate. While the findings are compelling, future controlled studies will be needed to confirm whether eating particular foods can affect long-term weight gain more than simply counting calories.  The study appeared in the June 23, 2011, issue of the New England Journal of Medicine.

Vitamin D and Obesity in Women
Posted by on June 10, 2011 - 7:08am

Overweight women with low Vitamin D levels who lose more than 15% of their body weight experience a significant increase in levels of this nutrient, according to a new study by researchers at Fred Hutchinson Cancer Center. "Since vitamin D is generally lower in persons with obesity, it is possible that low vitamin D could account, in part, for the link between obesity and diseases such as cancer, heart disease and diabetes," said Caitlin Mason, PhD, lead author of the study published in the American Journal of Clinical Nutrition.

Vitamin D promotes calcium absorption and is needed for bone growth and bone healing.   Along with calcium, vitamin D helps protect older adults from osteoporosis.  This nutrient also influences cell growth, neuromuscular and immune function and reduces inflammation.

The study involved 439 overweight-to-obese, sedentary, postmenopausal Seattle-area women, ages 50 to 75 who were randomized into four groups:   exercise only, diet only, exercise plus diet and no intervention.  Those who lost between 5-10% of their weight saw some moderate increase in vitamin D levels, but women who lost more than 15% of their weight experienced a nearly threefold increase in vitamin D, independent of dietary intake of the nutrient.   Optimal levels of vitamin D are between 20 and 50 ng/mL.  Levels below 20 ng/mL are inadequate for bone health and levels above 5o ng/mL can have adverse side effects such as an increased risk of kidney stones.

Feel Full on Fewer Calories
Posted by on March 18, 2011 - 8:55am

 

Grapes or Raisins?

Almost everyone who is health conscious agrees that American food portions are out of control!  One of our most visited blogs "Eat less, Move More" has generated a lot of comments and many readers are surprised how small portions need to be if you want to lose weight.   We've also received a number of suggestions like using a smaller plate, eating 5-6  mini meals every day, etc.   But the bottom line remains the same:   If you want to actually lose weight and you are not an exercise buff, portion control is a good way to go. However, not all portions represent the same amount of calories.

Feel fuller on fewer calories. This requires understanding the concept of "energy density".   Energy density is the number of calories (energy) in a certain amount of food.   High energy density means that there are a lot of calories in a small amount of food.   Low energy density means there are few calories in a lot of food.

One of the classic examples is raisins vs. grapes.    A one cup of raisins (dried grapes)  has about 434 calories.  A cup of fresh grapes has about 104 calories.  So to eat the same amount of calories, you would have to limit the raisins to 1/4 a cup!  Which choice would make you feel fuller?   One ounce of potato chips is 150 calories, the same amount of calories found in 3 1/2 cups of air popped popcorn.

In order to lose or maintain your weight, your goal should be to eat more  low energy dense foods.  That way, you eat larger portions that make you feel fuller.   Let's explore this density concept a bit further.   Several factors play a role in what makes food high or low in energy density.

1.  Water.   Fruits and vegetables have a high water content which provides volume but not calories, making them a low energy dense food.  A grapefruit is 90 percent water and a  half grapefruit is only 39 calories.  Watermelon is 92% water.

2. Fiber.  High fiber foods provide volume and take longer to digest, making you feel fuller with less calories.

3.  Fat.  Fat is very high in energy density (remember we are really talking about calories!).   One teaspoon of butter contains almost the same number of calories as 2 cups of low energy dense broccoli.

What about nutrition?   Does  "fullness" translate into a adequate nutritional intake?   What foods are better options when it comes to energy density?.    According to the Mayo Clinic Health Weight Pyramid:.

  • Most vegetables are low in calories but high in volume especially lettuce, asparagus, broccoli and zucchini.    Add more vegetables to your pastas instead of meat and cheesy sauces.   Put veggies on your sandwiches instead cheese slices and gobs of mayonnaise.
  • Fruits are healthy but some are lower calorie choices than others and certain fruits have more concentrated sugars (such as raisins) and have higher calories with less volume.   Fruit juices are also relatively high in calories and don't necessarily fill you up.   Eating a whole orange with its natural fiber will fill you up more than a glass of orange juice.
  • Carbohydrates are either grains or foods made from grains like cereals and pasta.  Select carbs that are higher in fiber like oatmeal, whole grain breads, brown rice and avoid breads made with refined white flour and sweeteners.
  • Fats are a high energy dense food but some are healthier than others.   Watch your portions and include monounsaturated and polyunsaturated fats in your diet like nuts, seeds, healthier vegetable oils (flax see, olive, and safflower oil). Just keep the portions small.
  • Sweets are high in energy density and are a challenge when it comes to caloric intake.   Try to find desserts that have low fat and sugar content, such as fruits and low-fat yogurt.  If they are baked, look for whole grain flour pastries.   The key to limiting the effect of sweets is to keep the servings small (share with your table mates--1 dessert, 4 forks--most restaurants are accommodating).
  • Protein comes from plant and animal sources and the healthiest low-energy dense choices are those high in protein but low in fat  such as lentils (also high in fiber!), skinless white meat, and fish.  Select fat-free dairy foods.

Substituting low density foods keep you from feeling food deprived, make you feel better about your meal and will help keep those calories down!  Here's a final example:   A small order of McD's french fries has 225 calories.  You could substitute (with the same amount of calories)  a salad made with a small apple, 10 cups of fresh spinach, and 1 1/2 cups strawberries with a splash of diet dressing.

Highly Active Women Gain Less Weight than Men
Posted by on December 16, 2010 - 3:03pm

People will gain significantly less weight by middle age – especially women – if they engage in moderate to vigorous activity nearly every day of the week starting as young adults, according to new Northwestern Medicine research.

Women particularly benefitted from high activity over 20 years, gaining an average of 13 pounds less than those with low activity; while men with high activity gained about 6 pounds less than their low-activity peers. High activity included recreational exercise such as basketball, running, brisk walking or an exercise class or daily activities such as housework or construction work.

“Everyone benefits from high activity, but I was surprised by the gender differences,” said lead author Arlene Hankinson, M.D., an instructor in preventive medicine at Northwestern University Feinberg School of Medicine. “It wasn’t that activity didn’t have an effect in men, but the effect was greater in women. Now women should be especially motivated.”

The study will be published Dec. 14 in the Journal of the American Medical Association.

There could be several reasons for the gender difference, Hankinson said. Women are less likely than men to overestimate their activity, according to previous studies. “Men may not be getting as much activity as they report,” Hankinson explained.  In addition, men in the high-activity group compensated by eating more than their low-activity counterparts, which could have led to more weight gain. The highly active women didn’t eat more than low-activity women in the study.

There were many ways to achieve the study’s definition of high-activity levels, Hankinson noted. One way was 150 minutes of moderate to vigorous activity a week.

The study participants -- 1,800 women and nearly 1,700 men — are part of the Coronary Artery Risk Development in Young Adults (CARDIA) Study, a multi-center, longitudinal and population-based observational study designed to describe the development of risk factors for coronary heart disease in young black and white adults.

Coauthor Stephen Sidney, M.D., associate director for clinical research at the Kaiser Permanente Division of Research. “Common medical problems such as heart disease, diabetes and obesity have their origins in childhood and can generally be prevented by maintaining a normal weight, not smoking, exercising regularly and eating a healthy diet throughout life.”

Hankinson’s research is the first to measure the impact of high activity over 20 years between young adulthood and middle age and to frequently examine participants (seven times) over that period. Study participants are more likely to remember and accurately report their behavior with regular exams, she said.   Previous studies, Hankinson said, looked at a single exercise intervention’s effect on weight for a short period of time or examined participants in longer studies at only two points in time -– the beginning and the end.

“We wanted to see if people’s activity levels during their youth were enough to help them keep weight off in middle age, or if they needed to up the ante,” Hankinson said. “It’s difficult to avoid gaining weight as you age. Our metabolic rate goes down. We develop conditions or have lifestyles that make it harder to maintain a high level of activity.”

“The study reinforces that everyone needs to make regular activity part of their lifestyles throughout their lives,” she said. “Not many people actually do that.” The active group in the study comprised only 12 percent of the participants.  Lower levels of activity had a negligible effect on weight gain in the study. “High activity was the only kind that made a significant difference,” Hankinson noted.

Marla Paul is the health sciences editor. Contact her at marla-paul@northwestern.edu

One in 4 Overweight Women View Themselves as Normal Weight
Posted by on December 13, 2010 - 8:44am

A new study found that nearly 1 in 4 overweight American women believes her body weight as normal, while conversely, around 1 in 6 normal weight women regards herself as overweight.

The study was done by researchers at the University of Texas Medical Branch (UTMB) and is published in the December 2010 issue of Obstetrics and Gynecology. Over 2200 women ages between 18 and 25 complete questionnaires that asked about health behaviors including how they perceived their body weight.  Then actual measurements were taken using the current standard definition of body mass index  (Normal 18.5-24.9; overweight 25-29.9; and obese >30).

Among the 1162 women that were actually overweight, 23% of them (misperceivers) believed they were of normal weight. Of the 1062 women who had normal weight based on their BMI, 16% considered themselves to be overweight.

The researchers concluded that weight misperception was especially common among reproductive age women and that this should be taken into account while counseling patients about weight management.

To reach the entire article found in Medical News Today click HERE.

Sugary Drinks Linked to Diabetes and Metabolic Syndrome
Posted by on November 24, 2010 - 12:45pm

In a new meta-analysis published in the November 2010 issue of Diabetes Care, researchers from the Harvard School of Public Health report that consumption of just one or two sugar-sweetened beverages per day is associated with a 26% greater risk of developing type 2 diabetes and a 20% increased risk of developing metabolic syndrome.   Senior author Dr. Frank Hu put this into perspective,  "So for those who drink two to three sodas per day, their risk of developing type 2 diabetes would be increased by 30-40% which is not very different from the increased risk associated with cigarette smoking."

It is not clear from the study if the main reason for the increased risk is due to the increase in calories or due to the combination of  excess calories and some unique metabolic effects of fructose and other components of soft drinks.

The authors note that the jury is still out on the long-term effects of artificial sweeteners in soft drinks, so they caution against substituting diet sodas or drinks for sugar sweetened ones.    Water, nonsweetened tea or coffee may be better choices.

Why Can't Americans, Be Less Fat?
Posted by on October 7, 2010 - 2:39pm

I just got back from a brief vacation in the Italian region of Emilia Romagna--the land of Parma ham, proscuitto, Pasta Bolognese and tasty hard cheeses. One of the regional specialties is a ravioli filled with spinach and ricotta covered in a butter sauce and sprinkled with parmesan cheese (Are your arteries choking yet?).    I was immediately struck by the lack of overweight people despite these wonderful foods that are high in fat and quite salty.   What is it about Italy that allows people to stay thin, yet eat these rich foods?

Now, I admit that this particular blog posting is not based on comparative research but rather a reflection on a brief vacation experience.   I really don't know if Italians have more heart attacks than Americans---but to the watchful eye, I was struck by all the healthy "looking" people who were strolling the piazzas who were significantly thinner than the people I see walking around the malls in America.  In fact, I saw almost NO overweight people.

Yes, they walk a lot, ride bicycles and spend time walking off their meals during their traditional passegiata (Lots of the men walk with their jackets thrown over their shoulders like a cape....molte elegante!).    But they also eat dinner very late (after 8 pm), close their shops for a 3 hour lunch break, and enjoy their  bread, wine and gelato.  On the other hand, not all meals are large, there are no fast food places in the small towns, and their cups of espresso hold about a tablespoon of caffe in those cute little cups.  Everything is freshly made and the small grocery stores are not lined with freezers filled with processed foods.

We spent some time with friends who lived in the community and learned that they have all their health care covered (even though taxes are high), work about 35 hours max. a week, and have 32 plus days vacation a year which they often spend in neighboring countries hiking and biking.  Many of the pharmacies provide basic health care services locally.    The school children play lots of sports and not everyone has a car.  Trains are plentiful between cities but, in the small towns,  the best way to get around is to walk.    Their houses and apartments are half the size of those in America but very adequate.   Their way of life seems more relaxed---everywhere you looked, people were gathered and simply enjoying each other----and talking to each other!    Cell phones were plentiful  but they didn't seem to replace face to face conversation.    I didn't see people eating at tables and talking on their phones as much as you see here.  They don't seem to watch nearly the amount of TV that Americans do.    I'm sure they have the usual worries about their jobs and families but they still have a quiet zest that permeates their everyday lives.   Overall, the stress level was definitely less apparent than it is in the U.S.    Maybe the word I am looking for is "content".   They seemed happy with their lives whether they were farmers, teachers or stay at home moms.

People say that traveling is educational.  On this trip, I learned that there are lifestyles that may be different---but perhaps better-- than ours.

Women, Smoking and Weight Gain
Posted by on September 21, 2010 - 4:01pm

Today,more than 200 health professionals attended the Institute for Women's Health Research at Northwestern University's first educational research forum of the 2010-2011 school year that  featured Bonnie Spring, PhD, a behavioral psychologist at Northwestern.   Her lecture entitled  "Untangling the Web of Women, Smoking and Weight"  made me realize how much we still need to learn about the power of addiction.  Here are some interesting notes about smoking cessation and weight gain from her lecture:

  • Reasons women continue to smoke:   mood and stress management, addiction/craving, social network, weight management.
  • Fear of weight gain discourages 50% of women and 26% of men who smoke  from quitting.   The reality is that 80% of people who quit smoking gain weight but the actual weight gain is about 6-10 lbs. , not the 15 lbs. that people assume.
  • The major cause of post cessation weight gain:   decreased metabolism (from nicotine cessation) and increased energy intake from snacks. Evidently, when we take away something the body values or provides pleasure (e.g., nicotine), we tend to substitute it with something else that we value (e.g. food).
  • Education about the benefits of not smoking is not enough to change behavior;  exercise alone to keep weight off while quitting smoking does not work.
  • Drugs sometimes used during smoking cessation to keep weight down work while they are being used, but once they are stopped, the weight returns.
  • Several studies have been conducted to determine if weight loss programs should be done simultaneously during smoking cessation therapy; shortly after smoking cessation has begun;  or completely after the person quits.  The results vary and it is not yet clear what the best approach is.
  • A lot of controversy persists around the question:   Do weight management efforts undermine tobacco abstinence?  Despite several national guidelines that state so, there is no study that demonstrates that trying to prevent weight gain while trying to quit smoking makes it less likely that a woman will succeed at quitting smoking, according to Dr. Spring.

Some promising approaches that are being evaluated include:

  • Sequential behavioral treatment (cessation, then diet and activity change) more effective than simultaneous treatment because it is  less overwhelming to the patient.
  • Exercise alone does not suppress weigh gain
  • Bupropion, varenicline, NRT suppress weight gain in the short term, but not long-term (after medications discontinued)
  • Weight acceptance (but so far tested only among very weight concerned smokers)

So the jury is still out on the best way to quit smoking.  Dr. Spring also shared some of the early advertising campaigns that were highly successful in raising the number of women smokers.   She noted, "Perhaps the best way to get women to quit smoking is to hire the companies that have been so successful in getting women addicted!"

Colorless Diet for Weight Loss?
Posted by on July 28, 2010 - 4:00pm

I just received a FDA email about the safety of color additives in food.   What caught my eye was the subheading:  "Without color additives, colas wouldn't be brown, margarine wouldn't be yellow and mint ice cream wouldn't be green."   I  wonder if colorless food could help reduce the obesity epidemic!!!   Seriously, to read the article, click here.

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