Very low calorie diets: how safe are they?

Do you recognize the urgent desire to lose all your extra pounds right now? If yes, then you are probably one of these people who have zero patience when it comes to losing weight and they engage in drastic solutions in order to reach their weight goal as quickly as possible. How effective, but also how safe all these very low calorie diets are?

The fundamental principle of weight loss says that weight loss is achieved when the energy consumed through diet is less than the one needed by the body to cover the needs of daily activities. An average person needs approximately 2,000 calories per day to maintain his or her weight stable, but those who follow a strict diet can dramatically reduce their energy consumption by intaking less than 800 calories on a daily basis. Diets very low in calories are popular among people who want fast results, people who are exhausted from long-term efforts to lose weight, athletes, or people who decide to go on a type of FAD diet.

How effective are very low calorie diets?

Diets producing fast results can be effective when followed for a short period of time. In a recent study realized in European countries, participants were able to lose an average of 11 kilograms in 8 weeks. But you should not be fooled by this exciting result!

Can I keep off the weight lost with a very low calorie diet?

Perhaps this is the most important question to be answered. Is it worth following a diet that will eventually result in gaining all the weight back? Studies have shown that if you follow a very low calorie diet to fit in your pants after the holidays, chances are that by next summer you will regain the lost weight. This is the well known yo- yo effect: you lose weight and then take it back and then begin a new diet, and so forth.

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Why are we doomed to get all the weight back when following a very low calorie diet?

This happens for a very simple reason. Very low calorie diets dot not follow a dietary pattern which can be adopted for life. For how long can you go without eating your favorite food? Moreover food is part of our social life including dining out with friends and family, habits which are almost prohibitive if you are following a low calorie diet.

From the rule above we can exclude those who, after engaging in a very low calorie diet for a short period of time, are able to adopt a healthy nutritional pattern (ie a diet which includes a variety of foods in moderate amounts). Moreover, key part of weight loss or maintenance is physical activity which helps use up the energy consumed through food.

What are the risks of a diet Express?

Following a very strict diet plan can create deficiencies in essential nutrients, because your body will use up its storages fast enough. As a result of this deprivation you can experience “shortage” in certain vitamins or minerals such as vitamin A, vitamin E, the B vitamins, folic acid, iron, zinc, magnesium and potassium.

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Fatigue is one of the most characteristic symptoms of people following a crash diet, as it does not fuel the body with the necessary energy and nutrients. Symptoms of deficiencies range from hair loss or dehydration, to very serious health conditions. Of particular importance are younger women who follow a strict diet and can create a calcium deficiency unchaining hormonal disturbances and disruption of their menstrual cycle (period).

In addition to the symptoms mentioned above very low calorie diets can result in loss of fluid and muscle mass, and less effective loss of fat.

express diaita_4If you want to lose weight avoid extreme solutions. A balanced diet is the one to help you reach your goal without being deprived and without dangerous side effects. Once you lose the desired weight, not only will you feel revived, but you will also know what to eat and what to avoid in order maintain a healthy weight. Remember that healthy weight loss rate is 0.5 to 1 kilograms per week, a number affected by gender, age, physical activity and other factors.




1. Academy of Nutrition & Dietetics. Evidence Analysis Libraries. Very Low Calorie Diets. 2007.

2. National Institute of Diabetes and Digestive and Kidney Diseases.  Very Low-calorie Diets. Τελευταία διόρθωση 31 Ιανουαρίου, 2014. Τελευταία ανάκτηση 1/10/2014.

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4. Reljic D1, Jost J, Dickau K, Kinscherf R, Bonaterra G, Friedmann-Bette B. Effects of pre-competitional rapid weight loss on nutrition, vitamin status and oxidative stress in elite boxers. J Sports Sci. 2014 Sep 26:1-12.