Do Very Low Calorie Diets Really Work?
posted on: February 09, 2017. posted in: Weight loss
We've had a question sent to us...
"Hi Liam what are your thoughts on VLCDs? Like The Cambridge Diet, Slim and Save and Exante etc?"
For those who don't know, VLCDs (very low calorie diets) are very restrictive dies where energy intake is less than 800 calories per day, and as low as 400 calories per day.
Now we all know the basic science.
Eat less than you burn, you lose weight.
Morbidly obese Jenny, weighing in at 16 stone, has a metabolic rate of somewhere between 3000 to 4000 calories a day.
If she starts eating 400 calories a day, she's going to create a huge calorie deficit (shortage of calories), forcing her body to burn off glycogen, fat and muscle to make up for the shortage.
The result is rapid, dramatic weight loss.
I've seen clients lose up to 20lbs in a week on these diets (mainly water and lean tissue, but yes some fat), so you can see why they're so appealing to desperate obese people who want to get their weight down as quickly as possible.
And I've seen clients lose 10 stone in 6 months, and literally look like a completely different person between January and June of the same year.
Fast weight loss. Dramatic transformations.
It all sounds really good doesn't it?
The problem?
Like all diets, and especially very low calorie diets...
The results. Don't. Last.
It wouldn't be so bad if it was just a case of Jenny being 16 stone, getting down to 10 stone, then stopping the diet and returning to 16 stone. At least she's no worse than when she started.
But the problem is that her body, and in particular her brain, cannot tell the difference between "The Cambridge Diet" or FAMINE.
Jenny's brain has a defence mechanism in place, an adaptation that has helped her ancestors survive for 100s of 1000s of years, through 100s of 1000s of famines.
That mechanism is called "ADDICTION".
We all think of addiction as something to do with drugs. But actually addiction is a natural cycle involving a part of the brain called "The Reward Centre", that reinforces certain behaviours. Modern day drugs just happen to artificially stimulate this part of the brain. But the truth is that it served a very ancient and very useful purpose.
When Jenny's Great-Great-Great-Great (keep going) Great-Grandmother was exposed to a famine, a shortage of calories, her brain adapted. It altered its own chemistry and hormones to deliberately make high energy food more REWARDING.
Think about it.
If you're starving, your brain protects you and defends you by making you want, crave, demand and obsess about FOOD, so you go out... seek it... and BINGE ON IT.
That binge isn't about Jenny's ancestor being greedy.
That binge is about Jenny's ancestor SURVIVING.
Binge eating isn't a disorder.
It is a DEFENCE MECHANISM against starvation.
Much like gasping for air is a defence mechanism against suffocation. Both gasping and binging are your body's way of getting resources into your body (oxygen and calories) whether you want to or not.
Fast forward a few thousand years, and Jenny is doing "The Cambridge Diet", living on 400 calories a day, and unquestionably starving her body.
Her brain thinks this is a famine, so it activates that defence mechanism by altering her brain chemistry to literally make her ADDICTED TO FOOD.
Food addiction. Binge Eating. Obesity.
These aren't diseases.
These are life saving adaptations.
And so....
Jenny does lose the weight. Jenny does transform her body. Maybe Jenny even poses on the front of a magazine with the title "Slimmer Of The Year". She's lost the weight. She feels great. She even recommends it to her friends.
But by starving her body, she stimulates her food addiction, and she activates increased BINGING.
The result?
She cannot sustain the diet. She loses control of her eating. She regains all the weight. And not just to the staring point. She actually regains EVEN MORE, meaning she is fatter than when she started.
The science is obvious when you think about it.
That extra fat.
That "BUFFER FAT" is her body's way of protecting her from any future famines. Like a few extra savings just in case that Cambridge famine happens to take place again, threatening her with starvation.
Repeat this process of starving... binging... regaining and laying down "buffer fat"... and you grow and grow... and adapt and adapt... and get bigger and bigger... and more addicted and more addicted... and better and better at STORING FAT.
Diets. And in particular low calorie diets...
Train. Your body. And brain. To STORE FAT.
That is how obesity is caused.
That is why we have an obesity epidemic.
That is why I warn people against diets.
Eat real food. Fuel your body. Train it and look after it. That's only way you will ever prevent this "starvation response" and lose bodyfat long term.
Liam
p.s. Have you ever lost weight and regained more on a diet? And do you now understand the science as to why?
