Yo-Yo effect and the dangers of short term diets.jpg

Yo-Yo effect and the dangers of short term diets

By: Dr. Thomas Kaiser

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It amazes me that we see new diets being published every week in lifestyle and other types of magazines. I would suggest that we force these magazines to label the diets with slogans like: “diets can seriously increase your weight” or “diets are dangerous”.

You may have read in the Daily Mail’s health section a few weeks ago that several serious research pieces have proved exactly that. The path to obesity often begins with a journey through a jungle of ever new and supposedly better diets.

There is a lot of talk about the so called “Yo-Yo effect” but I think this new buzz word is poorly understood by the reader and user.

Hence today I will try to go over the way our metabolism works and shed some light on the “Yo-Yo-effect”.

Wrong metabolism

The modern assumption that slim is beautiful and healthy is very new. For my grandmother, a healthy person had to be chubby. Her idea and taste was much more natural than ours. We are brainwashed by fashion and advertising and have started to really like that size zero body.

The fact that this is not natural is only slowly sinking in.

Our genetic building plan has different instructions. Objective number one is not to starve and to save for a rainy day. Nutrition, just like overpopulation, has never been a problem in the thousands of years of the evolution of human beings. These phenomena have only evolved in the last 60 years.

Our metabolism functions in such a way that it uses every calorie it is given either for direct energy supply or, if there is no acute need, in storing the offered calories for periods of hunger.

Our body has no option but to use or store ingested sources of energy.

This is how I start explaining to my many overweight patients why they need not feel hard done by if they put on weight easily. This really only means that they have a very well functioning metabolism and that they are healthy.

Our problem is that our modern lifestyle and our body are not in harmony anymore.

You can observe this every day on the street with around 30 per cent of children being too heavy. This is a very sad and new situation.

To summarise part one of my talk: our society is too heavy because we have the wrong metabolism for our lifestyle. It will take hundreds of years until the metabolism can adapt.

The Yo-Yo effect

The Yo-Yo effect is the logical consequence of our genetic makeup.

It consists of at least two components.

The first and simpler part is the fact that, after being really good for a few weeks during a diet, eating the right things and often being a bit hungry, it is only normal for an ordinary human being to enjoy eating more after the diet is finally over. So what happens is that, after losing a few kilos slowly, the body is quick to regain and even put on a few more kilos.

The second element of the “Yo-Yo effect” is much more specific and has only recently been better understood. You may remember your personal trainer telling you about the so called hyper-compensation effect after muscle training. What is meant, is that when you train outside your comfort zone, your body will prepare for the next “shock or stress” by building more muscle to be prepared.

The same happens if you bring your metabolism into an emergency situation, for example, if you feed it less than it needs. Next time it has a chance, when you start to eat normally again, it will prepare for the next hunger crisis by filling up the fat storage as much as possible.

This is why people who do radical diets without slowly changing their lifestyle and eating habits for good end up heavier than before they first started the diet.


Accept the fact that diets do not work in the long run.

The only healthy and effective method is long term improvement of eating habits and lifestyle changes. Especially important are physical activities and the right timing of your meals.

You need to trick your body very slowly and gradually into a new weight. There is something like a weight thermostat in our brains which can only be changed very gradually.

If you stay a new weight for more than six months your body will change the thermostat and accept this new weight as being normal for you. This is when it becomes easier to maintain the newly achieved weight.

Firm belief

What is very important for every mission in life is the firm belief that you are going to succeed and that you are doing the right thing.

If you strongly believe, like a lot of veteran dieters do, that looking at that box of chocolate will make them put on two kilos, it may well do exactly that.

Use visualisation techniques while you train and eat.

Dear Reader, make the most of these long and warm summer nights. Use them for long walks on the beach followed by a nice glass of red wine and only a small piece of dark chocolate. Remember, “A full stomach makes a poor lover”.

Best wishes

Yours Dr Thomas Kaiser

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