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by MARILYNN MARCHIONE

Diet not working? Blame your genes. That’s the pitch behind a new test that claims to show whether people will do better on a low-fat or a low-carb weight loss plan.

We’re all hard-wired with DNA that controls how we burn and store calories from various foods, and the test claims to sort out this machinery. A study this week found that women on diets well-matched to their genes, as defined by the test, lost roughly five times more weight than those on mismatched diets.

“We were able to explain why some people were successful” and others were not, even though they ate the same way, said Mindy Dopler Nelson, a nutritional biologist at Stanford University who led the study but has no financial ties to the maker of the test.

Some scientists find this hard to swallow. It’s another test being peddled without enough research to show it really works, they say.

“I’m afraid this may be another attempt to lure the public into purchasing genetic tests that provide little value for those struggling with their weight,” said Raymond Rodriguez, director of the National Center of Excellence for Nutritional Genomics at the University of California, Davis.

The research shows “nothing that should move the American public out to get their genome tested,” said Dr. Robert Eckel, a former American Heart Association president and cardiologist at the University of Colorado-Denver.

But it sure has appeal.

Gene testing originally was aimed at finding risk for things like cancer, diabetes and Alzheimer’s disease. Lately, genes have been linked to things you might not suspect, such as stuttering or compulsive leg-jiggling.

The latest trend is to connect genes to lifestyle counseling, determining what type of diet or exercise is best. That’s what the maker of the new diet test hopes to do.

The company then hired Stanford researchers to do a validation study of its $149 test, using people who took part in diet research that was published in 2007. That study tested four diets – Atkins (ultra-low-carb), the Zone (low-carb), Ornish (very low-fat) or a low-fat diet following the federal Food Pyramid.

About one-third of the original participants, 138 women, sent cheek swabs with their DNA to Interleukin, which tagged them as “low-carb appropriate” or “low-fat appropriate.”

Looking back at the original study’s results, researchers saw that women whose diets matched their genetic makeup lost more than 13 pounds over a year compared to less than 3 pounds for women on mismatched diets, Nelson reported at a heart association conference this week.

Some scientists were unpersuaded. Sticking with a diet is more important than what diet you choose, as is not regaining weight, Eckel said.

“I have serious reservations with this study and studies like it,” Rodriguez agreed. “The idea that genetic variants in these genes can predict the likelihood for weight loss in such a small population, particularly since the tendency for weight loss is probably more behavioral than genetic, is simply hard to believe.”

However, one of the study participants, Jacqueline Gardner, 55, of Evergreen, Calif., does believe. She went from 200 pounds at the start of the study to 185, but was back to 200 pounds two years later.

“I now know why I gained it back,” she said – the gene test showed she does not metabolize carbohydrates well. More recently, she has been on a high-protein diet and weighs 180.

“I wish I had had a DNA test 10 years ago,” she said.

The researchers also tested themselves.

“It confirmed my suspicion,” Nelson said of her result. “When I eat a lot of carbohydrates, I tend to put on weight.”

Do we really need a gene test to tell us that?

UC Davis nutrigenomics center: http://nutrigenomics.ucdavis.edu

Joanna Dolgoff, M.D.

Pediatrician, Child Obesity Specialist, and Author of ‘Red Light, Green Light, Eat Right!’

Remember when weight loss was simply about eating less and exercising more? These days, dieting is getting high tech. An increasing number of studies are being released about the benefits of new electronic weight loss gadgets. Should we embrace these gadgets? Will they actually help people to lose weight?

A recent study published in the British Medical Journal advocates the use of a small computer-linked food scale (called a Mandometer) to help with weight loss. The Mandometer was developed by researchers at Sweden’s Karolinska Institute. Dieters put their plates on this scale, which weighs the remaining food as the meal is eaten. A small screen shows dieters the rate at which they consume their food and the ideal rate at which they should be eating. When food is being eaten too quickly, the computer tells the dieter to slow down.

The goal of the Mandometer is to teach dieters to eat more slowly. As we have all heard time and again, it takes twenty minutes for the brain to tell the stomach that it is full. Many overweight people tend to eat too quickly and in turn consume more food than necessary before they are aware of their “fullness.” Studies have shown that when you eat more slowly, your body registers being full after fewer calories.

So does Mandometer work? Doctors in England studied its use with obese children age nine to 17-years-old over an 18 month period. One sample of subjects was trained to use the scale, while the other group was not. Both groups were counseled to exercise one hour a day and follow a healthy diet.

After one year, the subjects that used Mandometer witnessed their BMI drop by an average of 2.1 points. This decrease is three times greater than that of the study’s control group. Moreover, the individuals’ weight loss was maintained when measured 18 months later. At the end of the study, Mandometer patients were eating smaller servings at each meal and snack, while also consuming food more slowly than dieters in the control group.

I think the Mandometer sounds great. I constantly counsel my patients to eat more slowly. But I fully recognize that this is not always an easy task. People don’t realize how quickly they eat. A device that helps dieters eat more slowly is a positive step in the right direction!

The Mandometer is only one of the new high-tech weight loss devices hitting the market. Other groups of doctors are currently developing wearable wireless sensors to monitor the overweight as they go about their daily lives. The sensors document how often wearers exercise, how much they eat, and the location in which they eat their food.

Why is it so important to have this information clearly delineated? Studies show that when dieters “self-report” what they eat and how much they exercise, the data they offer is usually inaccurate. Dieters tend to underestimate portion sizes, exclude some of the “little bites” they have eat throughout the day, and exaggerate how many calories they burn when they exercise. By using this sensor, the information reported becomes more accurate and reliable.

Many of these high-tech weight loss devices are currently being developed. Some contain video cameras or Bluetooth-enabled cell phones so users can take pictures of their meals, thereby documenting portion sizes. Dieters take pictures of their food before and after eating. The information can then be sent to a lab where a calorie count can be determined. In some instances, dieters can get immediate feedback about their calorie intake!

These devices also contain accelerometers that can measure the length and intensity of a workout. If the device senses a prolonged period of inactivity, the wearer can receive a text message telling them to get moving!

But do these devices actually lead to successful weight loss? It seems logical that they would, but studies are still ongoing on their effectiveness. I, personally, would LOVE to try one of these sensors. I imagine that the cost of the device and the data interpretation would be high, but I think the results would be invaluable.

The bottom line is that most dieters underestimate the number of calories they eat each day and overestimate the calorie burn of their exercise sessions. A gadget to accurately gauge this information should help set the record straight. I believe that if these sensors become widely available, weight loss would become that much easier.

They were supposed to be wonder-drugs that prolonged your life. Now, there’s evidence that antioxidant supplements don’t help your health. In fact, they may actually be linked to an increased risk of dying while taking them.

For a new study in The Cochrane Library, researchers combined 78 clinical trials that involved close to 300,000 people. Over an average three-year study period, people taking supplements containing one or more of five common antioxidants were about 4 percent more likely to die. Beta-carotene, vitamin A, and vitamin E, seemed the most harmful, while vitamin C or selenium merely didn’t help.

Some of the participants were healthy, while others had heart disease, stomach conditions, or other health problems. The results suggest that, whether you’re healthy or coping with chronic illness, there’s no clear benefit to getting these nutrients in pill form, say the study authors. Antioxidants are still important—it’s just best to get them from food.

Too Much of a Good Thing?
Antioxidants work by fighting free radicals. “Free radicals are unstable molecules that, if left unchecked, can damage the cells and impair their function,” says Mary Hartley, R.D., M.P.H., a nutrition expert at AskMaryRD.com. Your body creates free radicals when you break down food, and they can also come from outside sources, such as pollution and smoking. The damage they cause has been linked to aging, as well as diseases like Alzheimer’s and cancer.

Antioxidants neutralize these free radicals. Which is a good thing—most of the time. For one thing, other recent research suggests zapping too many free radicals blocks the beneficial effects your workout. And though they’re harmful in excess, your body needs some free radicals to do things likefight infection.

Most people in the studies took doses of antioxidants that were higher than what you’d get by eating a healthy diet, and even larger than the government’s daily recommended amounts. This could help explain their negative effects, the study authors note.

Why were some more harmful than others? Studies suggest that at high doses:
•    Beta-carotene may actually make cancer-causing chemicals more dangerous
•    Vitamin A causes DNA damage
•    Vitamin E actually becomes a pro-oxidant, increasing cell damage

When to Take a Supplement
Scientists are still learning about all of the effects antioxidant supplements can have, alone or in combination. But based on these results, it’s a bad idea to take antioxidant supplements alone unless your doctor says you have a deficiency, Hartley says.

However, the threat from free radicals is greater if you’re under extreme physical or emotional stress: “Extreme is the key word,” Hartley says. If you’re getting divorced, training for an endurance event, or working long hours on a big project, consider taking a multivitamin supplement. “The supplement should contain 100-percent of the daily recommended intake for most, if not all, nutrients, and no nutrient should exceed the tolerable upper intake levels.” Here’s how to make sure you’re not going overboard:

Otherwise, stick to eating a healthy diet rich in fruits, vegetables, and other plant foods—getting antioxidants this way hasn’t been shown to cause harm. Plus, these foods contain other nutrients and thousands of other chemical compounds your body needs to function, Hartley says. Here’s what to stock up on for your antioxidant fix.

•    Vitamin A and beta-carotene: Sweet potatoes, carrots, and spinach
•    Vitamin C: Citrus fruits, red and green pepper, tomatoes
•    Vitamin E: Safflower oil, peanuts, and almonds
•    Selenium: Brazil nuts, sunflower seeds, brown rice