Weight: Thorough Study
Recently there have been two groundbreaking studies that have addressed that bothersome question of why there are so many people who work out but still stay overweight. This concern certainly resonates right now, as fit and muscular Olympians show off their physical prowess on land, water and air, inspiring millions of viewers all over the world to want to become as fit.
In a world that was fair, regular physical activity would make us nice and slim. However, numerous studies have shown that many individuals who start on an exercise program lose very little to no weight. In fact, some even gain weight.
In order to better understand why this is the case, anthropologists who conducted one of these studies started out by traveling to Tanzania ona research trip. They recruited volunteers there from the Hadza tribe. The members of this tribe still lead a hunting and gathering life to survive. Giving the tribe members a crash course on modern day field study technology, the individuals were fitted with GPS units, in order to meticulously measure the number of miles each of them walked on a daily basis while looking for food. They were also asked to drink doubly labeled water, which is a liquid where the normal oxygen and hydrogen molecules are replaced with ones that contain tracers. The researchers later studied elements from the individual’s urine to precisely determine what their metabolic rate and energy expenditure was.
Data was gathered by the researchers for 11 days. The participants average daily resting metabolic rates, energy expenditure and physical activity were then calculated. These numbers were then compared to the numbers for the average Western male and female.
It has long been thought that considerable physical activity is involved in a hunter-gatherer lifestyle that results in more calories being burned, which is many more than are burned by the average U.S. office worker on a daily basis. The scientists did determine that it was true that in general the Hadza people did move more than most Americans do. The women walked around three miles a day, and the men averaged about seven miles per day.
However, they were not burning a lot more calories. The scientists, in fact, calculated that the average metabolic rate for the Hadza, which is the number of calories that were burned in one day, was around the same as the Westerners average metabolic rate.
The scientists concluded that the implication was that active “traditional” lifestyle might not protect against obesity if there were changes in diet that led to an increased number of calories being consumed. So even people who are active will gain weight if they eat a typical Western diet.
The disheartening and underlying message from the study’s finding is that physical activity on its own will not make you thin or keep you that way. (Note that the Hazda people are nearly all thin individuals.)
The study’s overarching conclusion, which was published in the PLoS One journal, isn’t all that surprising or new, according to Dr. Timothy Church, from Louisiana’s Pennington Biomedical Research Center, who has studied weight control and exercise for a long time. According to Dr. Church, it has been known for quite some time that it is a lot easier to lose weight through dieting than through exercise on a calorie for calorie basis.
People also have a tendency to stay with low-calorie diets to lose weight than they do keeping up with regular exercise.
Another fascinating review and recent study, by Dr. Church and other researchers, helps to explain why. The main point from the study, like in the study of the Hazda, is that it appears that human metabolism is not as revved up through activity as was formerly believed.
Side effects explained
Dr. Diana Thomas, who led the study and is professor of mathematics at New Jersey’s Montclair State University says that there is an expectation that your metabolism doesn’t slow as you start losing weight or that it speeds up if you exercise. She adds that close mathematical examination of past studies on weight loss and exercise show that unfortunately that expectation is unfounded. One of the rare studies to scrupulously monitor metabolic rates, food intake and exercise found that the basal metabolic rates of volunteers dropped as they started losing weight, despite the fact that they exercised on a daily basi
s. Although they burned up to 500 calories in one exercise session, the volunteers daily total caloric burn was actually lower than if their metabolism had not changed. They also did not lose as much weight as had been expected.
The main problem for people who are hoping to burn off fat through exercise is that a majority of the current calculations on weight loss and exercise assume that a person’s metabolism either stays the same or increases due to exercise.
Dr. Thomas has started to recalculate weight loss formulas which takes into account this drop in metabolism. She is using the new formulas while working with volunteers at Pennington to provide them with better predictions on the amount of weight they really can expect to lose through exercising.
She says that these predictions are proving to be accurate, and although her weight loss forecasts are lower than they were with the old formulas, volunteers are happy. Dr. Thomas notes that meeting lower expectations is better than being disappointed that you aren’t losing the amount of weight that you thought you were supposed to.
Dr. Thomas might be her best advertisement. Over the past couple of years she has lost 70 pounds, and through the use of her formulas for the number of calories she actually is burning every day on her daily walks, she has not regained any of the weight.