Let’s not kid ourselves, losing weight, providing we aren’t referring to single-digit competition-ready levels of body fat, is not all that difficult. Providing the dieter sticks to their regime of eating less than they metabolically require for prolonged periods of time they will lose fat. Of course most folk in this day and age find even that to be too much hard work, but that is a different topic entirely. For the sake of this piece we will focus only on those who can lose the weight but find that the real challenge comes in keeping the weight off. This occurs because the brain appears to employ several biomarkers that keep tabs on your current metabolic condition (levels of body fat and energy flux), which once rise due to higher energy demands as you get fatter, do not seem to want to go back down to where they were. Thus, when you get fat and then manage to get lean again, your brain just isn’t happy and wants to be fat again. Exact reasons for this are still not firmly established, although evolutionary thought suggests it is a survival technique – the brain is essentially convinced that there is a famine and that the person is starving. Plainly put, the sudden and gross availability of food for humankind transpired much faster than humankind had to evolve to it. But the brain is fine with this – absolutely ecstatic probably, as it means starvation is no longer an issue for those with access to it.
Anyhow, these “raised” biomarkers leave major energy gaps, caused by the person having the appetite they had at a higher weight and the brain thinking that it requires the same amount of calories, along with a reduced level of energy expenditure. For a lot of dieters, the result of this is what has been called “yo-yo dieting”, where they will shed weight and then put it right back on, in a perpetual cycle. The latest research from the University of Colorado believe they have found the solution: exercise. I expect that a lot of readers will have stopped reading at this point, and some may have not even opened this article after reading the title since it all seems so obvious, but there appears to a little more to it than the fact that regular exercise burns calories.
After fattening up their pet rats to obese levels, they then dieted them down with a low-calorie diet. They split them into two groups, allowing one to exercise frequently while the other group did a whole lot of nothing. Both groups were given the freedom to eat however much they wanted, whenever they wanted it. While both groups regained weight, the exercising group regained much less and was eventually able to defend its lower body weight. The researchers found that the regular exercise not only burned calories, but also reduced their drive to eat, making body weight maintenance much simpler. The exercising group had lower body fat and biomarkers that overestimated the levels of body fat, almost convincing the brain that all is well. This reinforces the point that to be healthy and look good requires a complete lifestyle change, not a temporary alteration.
Source: Maclean PS, Higgins JA, Wyatt HR, Melanson EL, Johnson GC, Jackman MR, Giles ED, Brown IE, Hill JO. Regular Exercise Attenuates the Metabolic Drive to Regain Weight After Long Term Weight Loss. Am J Physiol Regul Integr Comp Physiol. 2009 Jul 8.