'I have a slow metabolism" is a classic excuse for people who explain their excess kilos and their inability to get rid of them. In fact, if your body doesn't burn off calories at a normal level and if you consume more food than the energy you expend, you will inevitably gain weight.
There are some lucky individuals who seem able to eat anything they want - even the most fattening foods - and remain slim. There are others who say they hardly eat anything but nevertheless gain weight.
"They may have forgotten the burekas and cakes," says Dr. Naama Constantini, a family physician, chairman of the medical commission of Israel's Olympics team and head of sports medicine at Hadassah Optimal, a center owned by the Hadassah Medical Organization for promoting healthful lifestyles and treating conditions not included in the basket of health services. "Or else they really do have a slow metabolism."
But it's possible to measure this objectively only at Hadassah Optimal in Jerusalem's Malha Technological Park and a couple of other places around the country. Constantini, one of the country's leading sports medicine specialists, wife of one of the country's top pediatric neurosurgeons and herself a very fit mother of seven, offers such testing and guidance on diet and physical activity at Hadassah Optimal.
THE CENTER, located on the second floor of Building #8, offers a unique metabolic system called Quark to measure the "resting metabolic rate" (RMR). Such testing is applied in certain medical centers around the world for individual weight management, obesity treatment, endocrinology, diabetes, cancer centers, malnutrition, metabolic syndrome, burn patients, intensive care, sleep disorders, pulmonary rehabilitation, cardiology, preventive medicine and more.
But the main purpose of RMR measurement at Hadassah Optimal is to define a customized weight management program based on a client's metabolism.
Quark (www.cosmed.it), manufactured by the Cosmed company in Italy, helps experts prepare a customized weight-loss program, based on a person's optimal daily caloric intake and exercise level. Used with questionnaires on lifestyle and energy expenditure, it can help the overweight to change their lifestyle and reduce the amount of fat in their body, says Shachar Nice, a physiologist who graduated from the Wingate Institute of Physical Education and Tel Aviv University, and who works with Constantini to carry out the tests.
"People who lose weight quickly," says Constantini, "are probably losing lean body mass [muscles]. This is not beneficial because muscle tissue has a faster metabolism than fat. If they lose lean body mass, they are likely to regain the weight. When dieting, one should lose fat, not muscle. There are also sportsmen who come to our center and waste a lot of time raising their heartbeat during exercise to levels that are either too low or too high. We are able to help them - and non-athletes - know their optimal heartbeat rate according to their individual bodies."
THE ENERGY burnt for the resting metabolic processes covers the largest portion of the energy a human body spends in a day. This amount varies widely from person to person.
First the patient - who must come after an overnight fast - is weighed, measured for height and asked about his age and lifestyle. It is best to undergo an RMR test in the morning, says Constantini, because metabolism rates naturally increase during the day. Coffee and other sources of caffeine, as well as food and exercise, raise the rate.
A plastic mask through which one breathes normally while lying on a cushioned table alone in a room for 15 minutes (it is so quiet and relaxing that some people fall asleep) is attached to the face and the heartbeat is monitored. The Quark device has a sensor that measures how much oxygen the person inhales and how much carbon dioxide he exhales. Gas exchange is measured sampling expired gas by means of a patented dynamic mixing chamber and provides data with a 30 seconds or more average time. A computer produces graphs that accurately calculate indirect calorimetry. At the end of the test, results are automatically printed out.
The Cosmed company recently developed a cheaper and smaller device called Fitmate, that measures oxygen consumption and fits inside a suitcase. An article was published in January in Research in Sports Medicine, in which researchers at Appalachian State University who tested the devices validated Cosmed's claims of accuracy.
Another device in the clinic, on which a patient stands barefoot for a few seconds, determines body composition - how much fat, water and muscle you have in your arms, legs, torso and abdomen - by monitoring bioimpedence.
BODY COMPOSITION, says Constantini, is one of the most important assessments to check if either diet or lifestyle changes have decreased the percentage of body fat and increased lean body mass. People who have diabetes or the metabolic syndrome that precedes diabetes should get rid of as much abdominal fat as possible to reduce the cardiovascular risk and improve their glucose and lipid profile.
"Bicyclists who take part in the Tour de France can expend as much as 6,000 calories a day," says Nice. "They don't have to worry about gaining weight. We don't have sportsmen coming for these tests. Our clients are people who have gone on diets with no positive results and those who lose weight and gain weight on 'yo-yo diets.'"
If they go to a health fund dietitian, she will most likely calculate how many calories you should consume according to your gender, age and weight and how much you exercise - all based on what you report. This is often inaccurate, and there is a great variation among people in the metabolic rate, says Constantini. Then she recommends what to eat or how much to exercise - or both. But health fund dietitians can devote only a relatively short time to each patient, and don't have the ability to test resting metabolism rates."
When people who indeed don't eat a large amount and do exercise still fail to lose weight, it is because their body's metabolism is slow.
"Some people have a very slow metabolism," explains Constantini. "The question is how much or why; a thyroid problem could be involved. Men, on average, have more muscle and less fat than women, thus their metabolism rate is faster."
Last year, Hadassah Optimal's Constantini was asked by the management of the Israel Corporation (which owns Zim, Tower Semiconductors and Israel Chemicals) to test dozens of executives who wanted to participate in a "health competition" aimed at increasing their fitness over a period of six months. Some chose to walk outdoors, others went to a health club while others said they'd work out at home. Shachar Nice was at their disposal to test their metabolism, advise them on how to increase lean body mass, increase aerobic ability, reduce fat and change their lifestyles. The results after re-education and workouts were dramatic. Some even continue to walk up the steps to their 22nd-floor office instead of taking the elevator. "I looked not only at their bodies but at the gleam in their eyes," says Nice. "They gained self confidence."
Rakefet Arieli, one of only a small number of trained sports dietitians in Israel, received her four-year bachelor's degree in nutrition and then her master's degree at the Hebrew University's agriculture, food and environmental quality sciences faculty in Rehovot. She is on the Hadassah Optimal team, obtaining printouts from the Quark system and then advising people on how to improve their metabolism and lose weight.
"We see people of all ages," she says. "Overweight and obese children and teenagers come here as well. We are against weighing 'ceremonies' as they can cause emotional problems. We teach them how much water to drink and how much to exercise, and discourage them from eating junk food. There are some people whose weight is normal but who have a lot of fat. We had an executive who couldn't bend down to tie his shoelaces but now does an hour on an exercise bike every morning. Some clients have even undergone bariatric (stomach-reduction) surgery to lose weight," says Arieli. "The way to do it is to increase lean muscle mass, because muscles burn more calories even at rest. In general, I am against calorie counting; it's best to learn how to eat properly and exercise more."
When a young adult comes in with a lower-than-normal metabolic rate and high triglycerides, Arieli advises weight training to increase muscle mass, eating fewer sweets and more protein, taking Omega 3 pills and balancing carbohydrates in each meal with protein to help reduce triglycerides. Such a person should eat some mini-meals, including fruit, during the day instead of eating just three meals and "fasting" in between.
Hadassah Optimal tests basic metabolism (daily energy expenditure) and an hour of nutritional counselling for NIS 590. Hadassah Optimal recently introduced its six-month, NIS 3,500 Opti-Fit program that includes RMR testing, exercise testing, a sports medicine specialist examination, physiological and nutritional counselling and group meetings monitoring every two weeks. One can also add in-house exercise training.
Although the national basket of health services doesn't include these programs and tests, some of the health funds are showing serious interest in partial coverage to those who have taken out supplementary health insurance policies. Making their members healthier and reducing their risk of diseases that are expensive to treat should induce the insurers to consider subsidizing wellness and lifestyle-change programs such as those offered by Hadassah Optimal.