Will losing weight slow down my metabolism?
A slowed metabolism is a fear for many dieters. Scientists generally agree that losing weight, especially when it’s done quickly, can alter our metabolisms. However, until recently, there wasn’t much research to suggest how long these affects lasted.
Scientist Dr Kevin Hall wanted to research into how losing large amount of weight can affect the body’s metabolism long-term. He decided to monitor the contestants from Series 8 of the reality show ‘The Biggest Loser’ to analyse how their bodies reacted to losing so much weight in such a short amount of time.
He found that, after six years, many of the contestants had regained large amounts of weight, despite their efforts to keep it off. Indeed, some contestants weigh more today than before they started the show.
Six years ago, when the show ended, researchers weren’t surprised to find that the contestants had metabolisms that were slower than expected. After all, the winner of the show had lost an astonishing 239 pounds in seven months! The surprising results of the study were yet to come.
As the years went on, the researchers were astounded when the metabolisms of the contestants failed to recover. It was as if their bodies were pulling every stunt they could think of to drive their weight back up to where it started. One contestant, who now weighs 295 pounds, has to eat more than 800 calories less than a similar sized man who has not dieted in order to maintain his weight.
These results help to explain why it is so hard for dieters to keep weight off once they reach their goal weight. Even after they switch back to a steady diet, their metabolism stays at a reduced rate which increases their urge to eat.
But what is it in the body that keeps the metabolism running so slowly after weight loss? According to Dr. Margaret Jackson, it’s due to a decrease in a hunger-controlling hormone called leptin. Jackson has conducted studies on animals which back up her theories.
She suggests that in order to combat weight regain, we need to devise a way to “trick” the brain into ignoring the hunger pangs that are caused by reduced leptin levels.
Jackson’s findings are corroborated by the results of Dr. Hall’s study as he discovered that after the Biggest Loser ended, leptin production was almost non-existent in the contestants. This led to them have intense hunger pains, cramps and cravings. The amount of willpower needed to remain eating healthily and exercising regularly whilst experiencing these symptoms is extremely difficult to maintain.
As the contestants began to put on weight, their leptin levels increased, but only up to about 50% of what they were before the show.
What can you do?
So, what does this mean for people on weight loss journeys? Well, at this moment, scientists haven’t found a way to regulate leptin levels back to a pre-diet level. Once you reach your target, you may find yourself feeling hungrier than you used to, with more frequent hunger pangs.
However, you shouldn’t let this put you off from overhauling your lifestyle and reaching your weight loss target. Obesity is one of America’s biggest killers; by reaching a healthy weight you will significantly reduce your risk of several major illnesses such as heart disease and diabetes. The risk of reduced metabolism seems a small price to pay for that.
To learn more about how your current diet choices affect your health click HERE