15 March 2010

Soup diets are a scam

Soup diets with exotic names such as "The Sacred Heart Diet" should rather be called "The Starvation Soup Diet" as they are unbalanced an potentially dangerous, warns DietDoc.


Every year I am flooded with questions about Soup Diets. Last year it was the "Cabbage Soup Diet", and this year it seems that this scam has changed its name again and is being called "The Sacred Heart Diet". 

Users always want to know if they will lose weight on these diets and of course the answer is “Yes”. But what these enthusiastic dieters don’t consider, is how unbalanced and potentially dangerous such starvation diets are.

Starvation diet

Instead of giving these soup diets exotic names like "The Sacred Heart Diet", they should rather be called "The Starvation Soup Diet".

Let’s calculate how many kilojoules a cup of vegetable soup contains if we use 2 stock cubes, 2 cups of chopped vegetables (carrot, tomato, cabbage, onion) and 1.5 litres of water to make our magic soup.

Water = 0 kJ
2 stock cubes (20g) = approx 141 kJ
2 cups chopped, raw veg = approx 705 kJ

Total kJ in 1.5 litres of soup = approx 850 kJ
therefore one cup (250ml) of this soup will provide 142 kJ

If you drink 3-4 cups a day, then your total energy intake for the day will only be 426 kJ (3 cups) and 568 kJ (4 cups) per day.

These energy intakes represent only 6.8% or 9% of the actual energy intake of the 6 300 kJ per day recommended for an adult woman who is trying to lose weight. For an adult man, they represent even less, namely 5.1% or 6.8% of the 8 400 kJ a day recommended for male slimming purposes.

It is obvious that anyone who only has about 7% or 9% of her recommended energy intake (or 5 to 7% of his energy allowance per day) is on a starvation diet and will start losing weight.


There are, however, a number of risks associated with the use of these magic soup diets, such as:

  • Lack of energy - anyone ingesting so little energy will be prone to tiredness, fainting spells and lack of concentration if the brain is starved of its necessary supply of glucose mainly obtained from carbohydrates 
  • Deficiencies - although it is luckily unlikely that dieters will be able to stick to this minimalistic diet for any length of time, if anyone should keep on using the diet for longer periods, he or she would develop deficiencies of practically all the known nutrients which may lead to a variety of diseases (iron or vit B12 deficiency anaemias, brittle bones due to a lack of calcium, suppressed immunity and increased risk of infections, hormone deficiencies due to a lack of essential fatty acids, etc)
  • Constipation, due to a deficiency of dietary fibre, may set in if slimmers use this diet for protracted periods
  • Muscle wasting as the body starts to use up its protein supplies to provide fuel for the body
  • Rebound reactions where the body stops losing weight in reaction to starvation and conserves its energy stores
  • Psychological changes, including depression, caused by a lack of serotonin in the brain. Serotonin levels in the brain are maintained by having adequate carbohydrate and protein intakes.
  • Rapid regain of lost weight once the dieter stops using these soup diets.

Basically no one should use a starvation diet unless this is done as a treatment for gross obesity under the supervision of a team of specialists including medical doctors and a dietician, and preferably in a hospital setting.


Although most people who need, or want to lose weight, would like an instant fix and to lose weight in the shortest possible time, most people do realise that these Soup Diets are a scam.

Even the names given to them are an indication of their duplicity.  A year or so ago, the soup diets were called the "Heart Association Diet", but when I contacted the SA Heart Foundation they assured me that they had absolutely nothing to do with this diet and that they were concerned that people using such unbalanced and extremely low-energy diets would do more harm than good.

The solution is not to waste your time and stress your body and psyche by exposing yourself to extreme diets. Rather use a well balanced energy-reduced diet that includes all the food groups and also has a low glycaemic index (GI).

Consult a dietician to assist you with an individual diet prescription. Visit the Association for Dietetics in SA website and click on "Find a Dietician" to find a dietician in your area.

Combine your balanced slimming diet with regular cardio exercise to simulate your metabolism, firm up your muscles and lift your mood.

This is the sensible approach to weightloss - it may take a bit longer, but you won’t be endangering your health or psychological equilibrium by using scam diets like the "Sacred Heart Diet".

(Dr IV van Heerden, DietDoc, March 2010)

Any questions? Ask DietDoc


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