An article in Scientific American magazine challenges how we look at exercise, diet, and weight loss.
Today we will discuss the truth about the relationship between exercise, diet and weight loss. This discussion is based on an article in Scientific American by a social scientist (not a doctor of medicine) who uses a medical test to determine the difference or similarity between true African hunter gatherers, and modern men to answer the questions: 1) Is there a difference between these two groups in how we burn calories and lose or gain weight, 2) has man adapted physically or socially to provide necessary methods to survive? and, 3) does the physical activity that man does cause him to lose weight or is it just diet? Because I have exposure to modern man and woman every day, I have the advantage of looking through this article and deciding whether it actually represents what modern man experiences when he or she is trying to lose weight. I do this with every study I read, and I found in this study that it does not jive with real life. The assertion that exercise does not change our weight is flawed when applied to real life.
We will explore the research done in this article that looks at two different social groups in regard to weight loss and exercise. Common sense would suggest that the more you exercise the more weight you will lose. This article says that’s not true. Their final statements say that exercise can help you lose weight up to a given point and then you hit a plateau, and even if you exercise more and more you do not lose any more weight. That is not true in modern life, and is simply not true in my practice of medicine.
Another interesting piece of conventional wisdom holds that physically active people burn more calories than less active people do. But again, their research suggests this is not true either. So how did they come up with this finding?
Herman Pontzer, an anthropologist at Hunter College studies energy expenditure in humans and great apes. The question asked by the research attempts to address differences between highly active primitive cultures like the hunter gatherers called the Hadza and the more advanced westerns cultures of north America and Europe.
His research utilizes what is called the gold standard of energy studies known as the doubly labeled water method. The two isotopes of deuterium and oxygen 18 are added to water and then urine is collected so the isotopes can be measured. This measurement will enable them to determine the amount of carbon dioxide and produced and by that method calculate the amount of energy they expend a day.
This research makes the point that contrary to common wisdom, humans tend to burn the same number of calories per day regardless of how physically active they are. But then he states that physically active people burn 200-400 more calories a day than inert folks…To me that ends up in weight loss if you don’t eat 200-400 more calories.
This social scientist then makes a huge jump in his research to compare active hunter gatherers’ caloric consumption and energy expenditure, to that of the great apes and other primates. Surprisingly, we have evolved to burn considerably more calories than our primate cousins do, but we have made that up with more and more calories.
One of the conclusions the researchers came to in the Hazda study was that hunting and gathering is a much more cerebral and risky high stakes game in which the currency is caloric and going bust means you die than they had thought. Savvy is just as important a survival skill as the physical skills used for hunting.
Because hunting is so unpredictable, it is necessary for survival that the women (who are not the hunters) forage for edible foods that can become the staple of the diet, which is then supplemented by the protein the hunters bring in. This creates what the authors of the study call a complex cooperative of food acquisition which makes us (humans) unique in the animal kingdom.
This study and others completed by anthropologists and scientists around the world have determined that there is no real energy expenditure difference between populations around the world no matter the level of physical activity or sedentary life styles. In fact the study with the accelerometers showed that couch potatoes expend about 200 calories a day less than moderately active people and highly active people are only slightly above moderately active people in expenditure.
So while the science is interesting the conclusions are still frustrating. We learn that exercise alone will not make you lose weight beyond a certain point if you are obese. All we know at the end is what we knew at the beginning, it takes a balance of diet, exercise, and lifestyle to maintain the proper weight for healthy caloric expenditures.
What the scientists have concluded by comparing human populations from various cultures and comparing humans to primates is that we have evolved physiologically in ways that require cooperative interaction and social life in order for us to live and that that interactive lifestyle has helped us evolve culturally so that we can survive in ever more complex units and groupings.
This Health cast was written and presented by Dr. Kathy Maupin, M.D., Bio-identical Hormone Replacement Expert and Author, with Brett Newcomb, MA., LPC., Family Counselor, Presenter and Author. www.BioBalanceHealth.com.