Why it’s hard to lose weight and keep it off

Danny-Cahill-Biggest-LoserFor those of us who fight a constant battle to drop unwanted kilos and keep them off – there’s some news. It turns out when your body wants to put that weight back on that you’re fighting against its natural inclination.

Research by Kevin Hall, a researcher with an addiction to reality television, followed the journey of competitors on the US version of The Biggest Loser to see what happened to them over the six years following their televised weight-loss journey.

His research will be released in the medical journal, Obesity, next week.

Danny Cahill set the record for the biggest weight loss on his way to winning The Biggest Loser in 2009. After losing 107kg (almost 236 pounds) in seven months he said that he had regained his life. But in the following six and half years, 45kg has come back on.

Anyone who has lost lots of weight knows of the struggle to keep the weight off. Even if you keep doing the same things, maintaining the same diet and exercise regime, the weight keeps coming back.

The reason is simple. When you reduce your calorie intake, your metabolism slows. In biological terms this makes sense. If your body is starved, and therefore under stress, it will take steps to preserve your life.

The trouble is, once you’ve been overweight for a while, it can take your body quite a bit of time to learn what “healthy” is. After all, if being overweight or obese is your body’s normal then it stands to reason it wants to get back to normal once it’s been stressed by a reduced calorie diet and extra activity.

What Hall found in his research was the resting metabolic rate of competitors in The Biggest Loser was lower at the end of the competition. At the start of the competition, the competitors’ metabolisms ran at a normal rate given their size. But by the time the show was over and the seven-month training and nutrition plan was complete their metabolisms had slowed and were not burning enough calories to maintain their thinner size.

In other words, they needed to further reduce their food intake just to maintain their lower weight.

It was the body’s reaction to being placed under stress.

According to Cahill, his metabolism has slowed so much that he needs about 800 calories less per day than someone else his size just to maintain his current weight – which is 45kg greater than his winning weight from the reality show.

What can we learn?

In simple terms, if your body runs at a calorie deficit (you eat fewer calories than you use) you’ll lose weight. The trouble with deprivation-based diets where we reduce calorie intake severely is our metabolisms slow as our bodies fight to protect the status quo – even if that status quo is unhealthy.

Very few people put weight on at the rate a The Biggest Loser Competitor loses it. Cahill dropped 107kg in seven months. That’s about 4kg per week on average. Cahill reached his initial weight of 195kg over a lifetime. His body had plenty of time to adjust, slowly, to its normal of morbid obesity.

Slow weight loss, that comes from a combination of diet and exercise, seems to be a better recipe.

If it took you five years to go from your preferred weight to your current weight, then a long term plan might be in order. Managing your diet so that you have a manageable calorie deficit that doesn’t slow your metabolism is a place to start.

And exercising regularly so your metabolism gets a kick is also important.

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