At left, man running. By Graysonbay - Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=12174170
There is an interesting article in the latest Scientific American about the “Exercise Paradox.” Perhaps you may have heard that diet is more important than exercise in losing weight. This article discusses the finding that daily caloric expenditure seems to be similar between peoples despite big differences in their activity level. Therefore, very active hunter-gatherers expend roughly the same number of calories as sedentary Western populations. The difference between the two in obesity is not due to caloric expenditure but caloric intake; thus, the authors claim that obesity is a disease of “gluttony not sloth.” In other words, the best way to lose weight is to adjust your diet (reduce caloric intake for example), exercise won’t do the trick (there have been a number of articles recently about this).
As to why caloric expenditure is similar despite ostensible differences in activity, we are not sure. The amount of calories expended per type of physical; activity seems to be the same between populations. Perhaps the hunter-gatherers rest more when not overly active or sleep better. Another intriguing possibility is that their bodies have adjusted to use less calories in regular “housekeeping activities” – the normal functions of bodily maintenance. In fact, the authors speculate that one benefit of exercise is to divert the body’s energy away from such potentially harmful processes as inflammation. And of course, exercise has a wide variety of positive effects on health and fitness – it’s just not the main vehicle for losing weight, which has to be diet.
How about the theory that increasing muscle mass is metabolically beneficial because muscle burns more calories at rest than does fat? This is still open to question, but this article makes one wonder if this is true. There is also the discussed phenomenon that the body can adjust to diet and decrease caloric expenditure, making it harder to lose weight by diet alone – is this perhaps where exercise or muscle mass plays a role? One possible advantage of so-called “cheat days” or “cheat meals” in a more restricted diet is to reset the body’s metabolic set point and once again allow weight loss when the (brief) “cheating” is over.
There is an interesting article in the latest Scientific American about the “Exercise Paradox.” Perhaps you may have heard that diet is more important than exercise in losing weight. This article discusses the finding that daily caloric expenditure seems to be similar between peoples despite big differences in their activity level. Therefore, very active hunter-gatherers expend roughly the same number of calories as sedentary Western populations. The difference between the two in obesity is not due to caloric expenditure but caloric intake; thus, the authors claim that obesity is a disease of “gluttony not sloth.” In other words, the best way to lose weight is to adjust your diet (reduce caloric intake for example), exercise won’t do the trick (there have been a number of articles recently about this).
As to why caloric expenditure is similar despite ostensible differences in activity, we are not sure. The amount of calories expended per type of physical; activity seems to be the same between populations. Perhaps the hunter-gatherers rest more when not overly active or sleep better. Another intriguing possibility is that their bodies have adjusted to use less calories in regular “housekeeping activities” – the normal functions of bodily maintenance. In fact, the authors speculate that one benefit of exercise is to divert the body’s energy away from such potentially harmful processes as inflammation. And of course, exercise has a wide variety of positive effects on health and fitness – it’s just not the main vehicle for losing weight, which has to be diet.
How about the theory that increasing muscle mass is metabolically beneficial because muscle burns more calories at rest than does fat? This is still open to question, but this article makes one wonder if this is true. There is also the discussed phenomenon that the body can adjust to diet and decrease caloric expenditure, making it harder to lose weight by diet alone – is this perhaps where exercise or muscle mass plays a role? One possible advantage of so-called “cheat days” or “cheat meals” in a more restricted diet is to reset the body’s metabolic set point and once again allow weight loss when the (brief) “cheating” is over.
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