Why Biggest Losers Regain Their Weight

The Truth About Fat
Image courtesy of Michelle Meiklejohn

My sons have become obsessed with “Biggest Loser”. They love the drama. They love the characters. I really think they are oblivious to the contestants’ weight. To them the weigh-ins are just numbers and it’s all a game. I realised this only after I had the “do you really think that we should be using other people’s weight issues as our entertainment?” chat. Perhaps it was a bit too deep for a 9 year old and a 6 year old. They do tend to take things a little more on face value than we do, don’t they?

Anyway, having sat through a couple of episodes myself, it’s heart wrenching to think that many of these people will put back on much of the weight they’ve taken off. But why is this? Why is it that people who have put themselves through so much, who clearly don’t want to be fat, simply find it too hard to “be like the rest of us”?

SBS aired a doco last night (13/05/2013) “The Truth About Fat”. I highly recommend you take a look. It’s available free to view until 27th May 2013. Some really interesting stuff. Be warned… there are a few needles and blood and guts bits. Just close your eyes if you can’t cope, as it is definitely worth a look. It may well turn your thoughts on obesity upside down, or it may confirm what you have had a nagging suspicion about all along.


Why has obesity reached epidemic proportions?

The program looks at research explaining what obesity might be all about. Traditionally, the thought has been that to be in a healthy weight range, you exercise more, or eat less. “Eat less, exercise more, or get fat” as my brother says to his son. And, this of course is 100% true. At the end of the day, being fat or thin is still pretty much about the energy equation. Take in more energy that your body is able to use up, and there is only one place for that energy to go. It turns to fat and is stored in adipose tissue in your body.

In today’s modern world, we eat more food than we need. It’s estimated we eat an average of 200 calories more than we need to every day. Doesn’t take long for that to add up, and for our collective weight to creep up over time. We have an abundance of food, rich in calories, and for some people, it is extremely difficult to resist. Being in a health weight range is just a matter of willpower isn’t it? Well, yes, to some extent it is, but there’s way more to it than that. A large  number of people find it almost impossible to exercise their willpower over the forces that compel them to eat. So what’s going on?

Our bodies evolved in a world where calories were scarce, and the opportunity to feast was uncommon. The developed world however is awash with food, and 25% of people in the developed world are clinically obese. What is it that shapes our decisions about food – what we eat, how much we eat, when we eat, and when we stop eating?



The simple answer is hormones. Ghrelin and PYY. Ghrelin is also known as the hunger hormone. It stimulates appetite, therefore increases food intake, and promotes fat storage. It is produced and released mainly by the stomach, and also in small amounts by the small intestine, the pancreas and the brain.

Peptide YY (or PYY), on the other hand, gives you a feeling of fullness, and signals when to stop eating. It is released into the small intestine after eating, circulates in the blood and binds to receptors in the brain, which results in a decreased appetite and a feeling of fullness. PYY release starts before food reaches the small intestine, and the amount increases as food hits the small intestine, hence the time lag between eating and feeling full. SLOW DOWN YOUR EATING!

The Truth About Fat showed that whilst ghrelin levels in obese people stayed pretty constant – ie they didn’t rise dramatically if they fasted, their levels of PYY were low. It’s thought that the lower levels of PYY prevent obese people from ever really feeling full. The research quoted obese people “I never really feel hungry, but once I start eating, I can’t stop”.

So, one thought is that hormones in obese people are simply different to people who are not overweight. Which makes sense of course, but what is it that causes some people’s hormones to go haywire?


Research with twins shows stress may be a factor

One line of research has looked at identical twins, who are different weights. Epigenetics is the study of changes in gene expression caused by our environment-not just our physical environment, but also life events that can have an effect on us. The fact that these identical twins can have the same genes but one is fat and one is thin, suggests that the fat gene can be turned on or off. Epigenetics can explain this.

There seems to be a  common thread amongst pairs of adult twins with discordant weight. People have pinpointed the time that changes in the fat twin’s body weight started to take place, and compared this to what was going on in their life. Interestingly, results point to times of stress being a factor in the switching on of the fat gene. My thoughts for some time have been that stress plays a huge role in being overweight. My first word of advice to anyone looking at losing weight is to look at their stress levels and attack that first. Once that’s under control, weight is likely to fall off with little effort.

The fact that what could seem to be very small events in your life might change your physical shape in the future, is both exciting and frightening, and at the same time tragic. Talking to people who really struggle with their weight, and seeing their frustration at how their life is limited by their obesity is a very sobering experience. How great that we are unlocking the key to turning their lives around.

This current research indicates that the assumption that fat people are lacking will power is not entirely correct. Simplistically, you can say that people who are fat lack the willpower to overcome their compulsion to eat, however, when your biology is working against you, the amount of willpower needed to overcome your eating habit is far greater than the willpower needed by thin people to eat well. So thin people of the world, no need to feel so superior. Hormonal imbalance and gene expression are not an excuse for being fat, they are a reason.


Gastric bypass surgery alters brain function

Another area examined by the program was surgery, specifically gastric bypass. Whilst a gastric by-pass does involve a drastic reduction in the size of a person’s stomach, it would seem that this surgery also works by changing the level of hormones responsible for obesity. People report not feeling hungry, but most importantly, feeling full when they eat. Patients themselves have reported that more changes have taken place in their head than their stomach.

MRIs looking at brain activity in obese people who are shown yummy fatty foods show lots of activity in the brain in the areas associated with addiction, emotional response and reward, compared to that of a thin person, who has little brain activity in those areas, shown the same photos. After gastric bypass surgery, obese people have been shown the same photos they were shown prior to their surgery, and their brain activity is greatly reduced to around the same level as a thin person. The bypass surgery seems to have pressed a reset button in their brain, returning the “fat genes” back to normal.

Gastric by-pass surgery of course has very real risks, and it is a last resort suitable for some people, but we are not far off less radical procedures to cure obesity.


Are we missing something here?

On the surface, it all seems very logical. We get fat because we eat too much and do too little exercise. Due to our biology coupled with certain environmental factors and life events, the pull of food is far greater for some people than it is for others. Medical intervention will fix this. Great. So, we may soon have a cure for obesity.

But given it would seem obesity can be caused by an oversupply of food coupled with stressors which switch on our fat gene, could it be that we are barking up the wrong tree. Would prevention not be better than cure? Is our consumer driven society not just stoking the obesity fire, and if we in the developed world shared the food around a bit and chilled out,  would we not all be a bit better off?