06 January 2006

Yo-Yo dieting = weight gain

Yes, Yo-Yo dieting has negative effects on future weight loss. It can lead to weight gain, not weight loss. Here's what you should know.

Yes, Yo-Yo dieting has negative effects on future weight loss. It can lead to weight gain, not weight loss.

Yo-Yo Dieting
Probably 70% or more of individuals struggling to lose weight, are caught up in the destructive cycle of Yo-Yo dieting.

Yo-Yo dieting is when someone who is genuinely overweight or imagines that she is overweight (but is actually not!) goes on a slimming diet, loses quite a few kg, stops dieting, reverts back to what he/she regards as ‘normal’ eating (loads of high-energy foods with a high fat content) and not only regains all the weight she/he lost, BUT also gains extra weight so that the person ends up weighing more than at the start of this futile exercise.

After a while, these people try to diet again and find that their efforts are unsuccessful, they then get depressed and eat even more, gain even more weight and become seriously obese.

Basic Metabolic Rate (BMR)
Yo-Yo dieting has a most unfortunate effect on the so-called Basic Metabolic Rate (BMR).

The BMR is the amount of energy a person uses up when he/she is at rest. The BMR is the amount of energy you need to keep your body ticking over when you are not doing anything active, e.g. sleeping, sedentary work, resting, watching TV, etc.

In a sedentary individual the BMR is responsible for 60% or more of the energy expenditure. In highly active people, the BMR can drop to zero because practically all the available energy is used up by physical activity.

Something that is not well known, is the fact that the BMR increases as overweight increases, i.e. an obese individual will have a higher BMR than a thin person and actually uses up more energy just to keep his/her vast body ticking over than the thin person.

When someone loses weight, his/her BMR decreases. In other words, if you have lost those 10 kg by really strict dieting and regular exercise, the amount of energy your body will burn for its basic processes will be lower than when those 10 kg were encumbering your body! This is a seemingly paradoxical situation, but it is unfortunately true.

Metabolic Disaster
Yo-Yo dieting is really a metabolic disaster. What happens in the human body when cycles of weight loss and weight gain are repeated over and over again as is the case with so many overweight people?

Because the BMR (an energy burning process) decreases when we lose weight as our bodies adapt to the lower energy intake, individuals who stop dieting and start eating energy-rich foods again will gain more weight than before.

The next time this cycle of weight loss and gain is repeated, the BMR will be lowered even further and your body will use even less energy for its basic metabolic processes. If you once again drop the diet and indulge in fatty foods your weight will rocket and you will end up heavier than ever.

Each time the destructive yo-yo cycle is repeated, the body’s ability to burn fat decreases until you reach a point where weight loss theoretically becomes close to impossible. Yo-Yo dieting is truly a metabolic disaster.

A ray of hope!
However, all is not lost!

If you go on a sensible low-fat, high-fibre diet and do regular exercise, you will eventually start to lose weight. It may take much longer if you have been a Yo-Yo dieter, but the use of exercise will compensate for your decreased BMR. This is one of the reasons why experts emphasise the use of exercise together with an energy-reduced diet to achieve weight loss.

If you have been caught up in the trap of Yo-Yo dieting, you need to be patient and allow your body to slowly lose weight and you must combine the diet with regular, intensive exercise.

The catch
There is a catch to losing weight if you are a Yo-Yo dieter. Once you have managed to lose weight, you need to stick to the low-fat eating plan and the exercise for the rest of your life!

A word of warning!
Those of you who have never dieted before or been caught in the web of Yo-Yo dieting, should make quite sure that you don’t get into this destructive cycle. Go on your diet and do your exercises and when you have lost the desired amount of weight, please don’t revert back to unbalanced eating, otherwise you will join the ranks of those unfortunate individuals who struggle to lose weight for the rest of their lives because of Yo-Yo dieting. - Dr I.V. van Heerden, registered dietician.


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