The Wrong Way to Lose Weight
By Beth Spicer
More than once, I've addressed the topic of low-calorie dieting for weight loss, showing the futility of this brute-force approach. But are these type of diets an acceptable means of reducing for a short period of time, for example, in anticipation of that upcoming 25th high school reunion? Many would argue that a few weeks or months of the Nutrisystem or Weight Watchers regimen never hurt anyone, if followed by a maintenance program of "normal" eating. But the truth is, even a brief period of significant calorie reduction will dramatically adjust the body's level of "energetic efficiency"--the rate at which calories are partitioned toward energy versus fat storage, making this not only a useless way to alter one's physique, but a detrimental one, as well.
Let's look at some scientific research on the subject. Here's what happened when a group of rats decided to "drop a few pounds" for their high school reunion. In a cleverly designed experiment ("Adaptive Changes in Energy Expenditure during Refeeding following Low-Calorie Intake", Am J Clin Nutr 1990; 52:415-20) by long-time obesity researchers Dulloo and Girardier, half of a group of young rats were put on a diet, while the others were allowed to eat whatever they wanted (the "ad libitum" group).
The dieters were fed exactly 50% of what the ad lib rats ate spontaneously, for a period of 30 days. At the end of that time, the dieting group was then matched to a third group of rats by both weight and body composition. For the next 25 days, the previously food-restricted rats were fed exactly what these similar-sized, non-dieted rats chose to eat naturally. If the body had no ability to adapt to caloric reduction, the two groups of animals would be expected to gain lean and fat at the same rate, but in fact, that was not at all the outcome in this case.
Since they were young rats, they all gained weight during the 25 days of pair-feeding, but the raw gain and relative proportions of fat and lean tissue were vastly different. The previously-dieted rats gained the same amount of lean tissue, about 25 grams, but more than twice the fat of their free-eating counterparts--35 grams versus 15! Thus, they not only gained more weight overall, but so much more of it as pure fat (58% vs. 36%), while eating the same number of calories as rats who were initially similar in size and body composition. The only explanation for this is that the 30-day low-calorie period devastated the fat-burning machinery of the diet group, so that they not only recouped lost weight but turned into fat-storing machines.
Thus, when dieters return to "normal" eating, where normal is the amount eaten by a person of similar size and body composition to their new, thinner physique, they will lay down fat like nobody's business. But you don't need me to tell you that, if you've ever been on a low-calorie diet; you've experienced it first-hand. You've felt the anguish of watching everything you worked, sweated, and starved so hard to take off, jump right back on your bones as though they were magnetic. There's probably no worse feeling than stepping on that scale every day, when you're trying so hard to keep the weight off, and seeing those numbers creep-creep-creeping back up.
But does it have to be this way? No, it doesn't, as long as you steer clear of low-calorie diets as the means of reducing. As the pair-fed rat study shows us, diet and exercise programs which cause weight loss through caloric deficit are not useful in the long-term, and in fact, sabotage our efforts and make lasting weight loss impossible. Instead, we must develop an understanding of the physiological causes of obesity and work on treating them, rather than simply applying a painful and often expensive bandage over the problem.
Learn more about the truth behind weight loss diets and the physiological abnormalities that cause obesity at http://www.trianglepubs.com", where researcher Beth Spicer presents critical reviews of medical research studies that you won't hear about on the evening news.
