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Report of experts participating in Task 7.3

September 2002

Collection of data on products intended for use in  very-low-calorie-diets

Directorate-General Health and Consumer Protection

The report documents the extent of the problem of overweight and obesity in the EU and corrects a number of misconceptions ie. that slow, small weight loss is better maintained or that rapid weight loss is unsafe.

When the SCOOP Task 76.3 was first announced, the VLCD European Industry Group asked to submit a report which had been prepared by Dr John Marks (one of the members of the SCOOP committee and one of the authors of the above SCOOP document) in March 1998. The SCOOP Committee, during the first plenary meeting in Maastricht, The Netherlands on March 15th and 16th 2000 accepted this report. 

A request was made by the SCOOP Committee that those sections of the report which were concerned with scientific and medical data be updated to early 2000 and submitted as a discussion paper.  Subsequently a series of further papers was requested by the Committee and submitted in the years 2000 and 2001 by Drs John Marks and Jaap Schrijver..

 The document which is referred to in the SCOOP Report to the EU Commission of August 2001 as Marks J and Schrijver J (2001) is the summation of all these reports from March 2000 to July 2001.   This very detailed and lengthy  scientific paper can be found on Dr Mark's  web pages (click here)  Dr Marks has, however, provided the Food Education Society with a summary analysis of the highlights of  his paper with links to the supporting section of the paper for those interested in the relevant research documentation.

 

SUMMARY ANALYSIS AND LINKS TO REPORT

PREPARED BY DR's JOHN MARKS and Jaap Schrijver

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This report reviews over 400 published scientific and clinical studies to early 2000, undertaken on VLCDs, on over 50,000 people. Thus it is likely that VLCDs are the most widely studied of all weight reducing diets. In addition, it records the main findings in a series of audit studies undertaken during the routine use of VLCD.

The vast majority of the studies identify the compositional standards and the length of administration and this document concentrates on those papers. In almost 20,000 people, use was for more than four weeks, giving good evidence on safety of long-term use.

In addition current formula VLCDs have been used by well over 25 million people in the international community over a period of over twenty years.

In addition to this critical review of the available safety and efficacy data in clinical use, there have been a substantial number of recent experimental studies which have shown that some of the earlier research reached erroneous conclusions. This report reviews this data and highlights some important new scientific conclusions which have practical implications.

Overall conclusions

A modern nutrient-complete VLCD provides a highly effective and safe method of weight reduction. The use of VLCD has benefits on excess weight related disorders which appear to be superior to those of LCD or food based plans probably on the basis of the more rapid weight loss.

On the basis of monitored clinical experience coupled with recent body composition studies a scientifically based standard for composition and labelling can and should be established for VLCD.

 In view of the undisputed need to help the very large number who need to lose weight, as many safe methods as possible should be made easily and readily available. This includes VLCDs, where the safety can be shown to be at least as good as diets in the >800kcal energy range. VLCDs should therefore be available on free sale on the same terms as diets of over 800kcals (see Commission Directive 93/5/EC).

 

 

Overweight and obesity are rapidly and substantially increasing problems in all European Union  Member States 

 

Excess weight has reached epidemic proportions with some 20% obese and a further 30% overweight (Section1.1)

 

 

Morbidity increases from a BMI of about 24 . The problems associated with excess weight include not only serious physical diseases, but also psychological and social ills 

 

Excess weight is strongly correlated with increasing mortality. 

 

The economic cost of excess weight is substantial. 

 

 

THE SAFETY OF VERY LOW CALORIE DIETS IN EXPERIMENTAL AND CLINICAL USE   

The need for strict attention to prime data is high. Years of misinformation has led to a large catalogue of ex-cathedra pronouncements.

Closely monitored clinical studies in over 50,000 people, many for prolonged periods with laboratory investigations and electrocardiographic monitoring show no evidence of pathological changes as a result of the use of VLCD. This confirms the practical experience of use of VLCD in over 25 million people during more than 20 years. This section examines the lack of  relevance of the  "liquid  protein diet" .

These studies show that products with an adequate macronutrient and micronutrient composition, with an energy content in the range 400-800kcals per day (VLCD) are at least as safe as any other weight reducing diet.  The safety applies not only to those in the higher BMI range but also to those with starting BMI levels down to 25 and finishing BMI levels in the normal range (20 to 25). 

Click the link for a summary of the available published data on diets under 800kcals and for the data reclassified according to energy and carbohydrate content.   A full listing of these studies is given as Appendix I and a full bibliography for them is given as Appendix II.

 

Clinical studies demonstrate that there are a negligible number of significant adverse reactions in the studies (over 50,000 dieters) or in routine use in several millions under free sale use (Section 2.3)

Side effects of VLCD: A relatively small proportion of those taking VLCD experience side effects. The risk of side effects is greater if the dieter does not follow the directions given on the diet pack or by any adviser (particularly of strict compliance to the diet and to drink substantial quantities of water while taking the VLCD). 

Clinical and electrocardiographic studies show no damage to the heart during VLCD use 

Gall Stones:( Cholelithiasis)  Examination of the literature shows that, with very rare exceptions, claims of increased incidence of cholelithiasis with rapid weight loss are American. The European literature is devoid of such reports and conversations with those European experts who have used VLCD extensively confirm that gallstone formation has not been a problem. Perhaps even more importantly, in those papers in which the details of the weight loss programme are recorded, the majority stem from two commercial weight loss products widely used in the USA but not in Europe.

Clinical and biochemical studies show no organ damage during weight reduction using VLCD 

Bone density: It is clear that, as could be logically expected, there is a direct relationship between bone density and body weight. It is largely the strains on the bones that determines their density. That is why elephants have thick bones and orthodontists are able to move teeth. Whether weight is lost intentionally (by whatever means) or unintentionally, the bone density is reduced roughly in proportion to the loss of weight. Bone density is increased with increasing weight and reduced proportionately with weight loss.

The more rapid rate of weight loss during the use of VLCD has no additional adverse effects .

Eating Disorders: There is not one iota of data to support a causitive relationship with dieting.

There is no additional difficulty in weight maintenance after the use of VLCD 

Resting Metabolic Rate: The initial  reduction in resting metabolic rate (around 15%) is a physiological response to reduced food intake within the first few days of dieting and is not related directly to the actual energy intake or to the amount of weight loss. The subsequent long term reduction in the resting metabolic rate depends on the extent of the weight loss irrespective of the method and energy levels by which it is achieved 

Weight cycling (yo-yo dieting) is not advised but is a feature of all dieting methods unless good weight maintenance practice is followed. Weight cycling  is no greater with the use of VLCD 

 

 

Continuous versus intermittent use: There is no scientific reason for short term interruption of use, indeed from the point of view of experience it is highly undesirable and de-motivating. 

 

 

In group studies in which there is good compliance, the rate of weight loss depends upon the energy level of the diet (Section 2.6).

The weight maintenance  results with VLCD are as good, if not better than with the use of other methods of dieting Weight cycling:(Yo-Yo dieting): Weight cycling does not lead to increased fat stores, reduced metabolic rate, and less effective weight loss with each cycle as was previously suggested

The only way to achieve long-term weight maintenance is by a fundamental change in lifestyle. The long-term results achieved by weight reduction by VLCD are at least as good as with those other non-invasive methods 

 

Since liquid protein diets (LPD) were discontinued, there have been no further deaths identified since 1977/1978. Nevertheless the information relating to LPD is re-examined and is shown to have no relevance to current VLCD. (Section 2.3.1 &2.2)

Body Composition Changes associated with dieting. Virtually all of the resistance to the use of VLCD has centered on the allegation that VLCD might cause excessive loss of  lean body mass  in comparison with other diets.

 

A vast amount of modern research has been dedicated to determining  whether these concerns were warrented.  It has been proved that there is no excessive loss of body lean, however for those interested in the scientific detective story resulting in understanding the reasons why the concerns were misguided, the next sections will prove illustrative.

Although many older studies used Kjeldall nitrogen determinations for estimating protein changes, the technique requires unusually great attention to detail to achieve reliability. Conclusions from studies without  validation controls (rarely used) should be avoided .

A thorough examination of body composition estimation has indicated that there was substantial lack of reliability and reproducibility in most of the methods that have been used for weight loss studies. 

With the exception of neutron activation, which is expensive and not widely available, all the body composition methods are indirect estimates. The estimate is influenced by variation in formulae which are used for converting the observation as recorded to the body composition estimate 

 

Physiological variations also can profoundly alter the results.  

 

In consequence it is inappropriate to compare data derived by different techniques in the same chart 

 

The most widely used reasonably reliable indirect technique is hydrodensitometry and unless otherwise stated we have concentrated on data derived by this technique.

 

Unrecognised analytical variation may explain the erroneous conclusions of Forbes on compositional changes during weight loss 

 

The Keys (1950) Minnesota study, often quoted as confirming that fat free mass (FFM) loss is greater in individuals with less fat is irrelevant down to the lowest level (about BMI  20) at which dieting is justified. 

 

The loss of lean body mass (protein) is inherent  and necessary with any weight loss, regardless of energy intake, because weight gained is not 100% fat. There is no proportionately greater lean body mass loss with VLCD providing over 40g high quality protein per day than with LCD.

 

Re-examination of the old data and further new observations support the view proposed by Garrow and others in the 1970s, that at all pre-dieting BMI levels between about 60 and 20, FFM represents about 25% of the weight loss (range about 20-30% probably depending on genetic factors). This is true for any energy value diets containing appropriate macronutrient levels including VLCD 

 

 

Loss of lean body mass is inherent in any weight loss, which implies an obligatory nitrogen loss during weight loss. Hence excess nitrogen loss is only relevant if it is greater than the obligatory loss. At daily intake levels of 40-50g protein in the diet, loss in excess of that which is obligatory is unusual.

 

There is no clinical or valid experimental evidence which indicates that carbohydrate levels above those currently available and widely studied, i.e. about 40-45g per day (representing about 90% of the available clinical data) have any merit.

 

Continuous use of VLCD to the desired weight is preferable to intermittent dieting for both physiological and psychological reasons, and has no disadvantages

On the basis of the extensive amount of data reviewed the following compositional criteria are proposed which would provide the following minimum daily intake:  

Protein: 50g per day with a minimum nutritional quality as defined by WHO/FAO (FAO, 1991)

 

Carbohydrate: A minimum available carbohydrate intake of 45g per day  

 

Fat: A minimum of 7g neutral fat per day which would provide not less than 3g linoleic acid and 0.5g linolenic acid with a linoleic/linolenic acid ratio between 5 and 15  

 

Micronutrients: Internationally agreed levels should be adopted. 

 

Fibre: The fibre recommendation should allow for soluble fibres to be used. The minimum should be 10g per day. The available component of this should be included in the carbohydrate figure. 

 

Energy:      The energy value per se has no direct relevance and provided minimum macronutrient levels are defined the energy value is equal to that provided by these essential nutrients. 

There is substantial medical and scientific justification for modern nutrient complete formula diets with an energy value less than 800kcals per day (VLCD) 

 

There is recent convincing evidence that the rapidity of weight loss confers additional positive health benefits independent of the weight loss in, for example, non-insulin dependent diabetes mellitus and hypertension.

 

The precautions for VLCD use should be those which apply to any method for losing weight.  

Those with defined medical conditions, those dieting for prolonged periods and those receiving prescription drugs should seek medical advice and/or supervision following the same advice as those using LCD. 

 

As with any weight loss diet, medical supervision is only necessary if there are medical complications.

Having studied the draft of the SCOOP Report on VLCD the authors of the discussion paper (Marks and Schrijver) drew attention to some inconsistencies and contraindications within the SCOOP Report.