Reports on tasks

for scientific cooperation (SCOOP)

EXECUTIVE SUMMARY

AND CONCLUSIONS

Task 7.3 – Collection of data on products intended

for use in very-low-calorie diets.

Report September 2002

Reports submitted on behalf of the VLCD European Industry Group to the SCOOP working group on very-low calorie diets between 1998 and 2001, consolidated 2001.

by

 John Marks MA, MD, FRCP, FRCPath, FRCPsych    Life Fellow, Girton College, Cambridge CB3 0JG

 and

Jaap Schrijver   . Manager Corporate Regulatory Affairs for foods for particular nutritional uses (PARNUTS) - Royal Numico NV

Introduction

When the SCOOP Task 76.3 was first announced, the VLCD European Industry Group asked to submit a report which had been prepared by one of us (JM) in March 1998. The SCOOP Committee, during the first plenary meeting in Maastricht, The Netherlands on March 15^th and 16^th 2000 accepted this report. A request was made by the 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 for the next meeting. Subsequently a series of further papers was requested by the Committee and submitted in the years 2000 and 2001 by JM and JS.

The present 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. It has been edited to try to remove any overlap resulting from the need, during the various meetings of the Committee to explain the background to the further reports. In addition the information is not presented in strict chronological order but in relation to the topics that were covered.

 Possible conflicts of interest.

These original documents were prepared by one or both of us as independent scientists and were not discussed with the European VLCD Group. However members of that group were very helpful in finding copies of overseas scientific papers not available in United Kingdom libraries and in providing background data relating to their own studies. 

Neither of us is currently employed by any of the member companies of the European VLCD Group though John Marks has, in the past received a fee as Consultant to Cambridge Nutrition Ltd.. Over the period of the preparation of this report John Marks has been a Life Fellow of Girton College, Cambridge.

 Jaap Schrijver has his expertise in biochemistry and nutrition. He is employed by Royal Numico NV since 1991. He holds the position of Manager Corporate Regulatory Affairs for foods for particular nutritional uses (PARNUTS). These foods include VLCD products although the company has currently not an interest in these products. As a representative of the Dutch association for PARNUTS foods, he participates in the regulatory activities of the Association of the Food Industries for PARNUTS (IDACE). The IDACE secretariat has its office in Paris.

Acknowledgement

I want to express my particular thanks to Dr Stephen Kreitzman and Valerie Beeson of Howard Foundation Research Ltd., who undertook a substantial proportion of the original research on which Section III, the 'Recent Scientific Studies' is based. Not only did they make available to us copies of the published work, but also shared with us much of the basic data so that we could convince ourselves that their results, which demonstrated substantial misunderstanding in much published metabolic work, could be thoroughly checked. On the basis of this, we were not only able to confirm the validity of the Kreitzman and Beeson  studies, but from their bibliographies undertake cross checks of the errors or omission in the earlier work. 

We want to make it quite clear that we found no evidence of deliberate distortion or deliberate misinterpretation in the early works.  Most of the errors occurred because the biological scientists did not fully understand the assumptions involved,  exactly what their indirect methods of determination meant or the extraneous factors that influenced their results and  interpretations. 

EXECUTIVE SUMMARY & CONCLUSIONS

 Preamble

 This report presents evidence for VLCDs collected since the Scientific Committee for Foods Report of 1990.

In 1990 the SCF Report was based largely on the experience of one (United States) group and ignored not only reports prepared by European Member States (UK and The Netherlands) but also extensive studies by European nutrition experts.

In addition to work which was not reviewed for the 1990 report, there is a large body of new evidence since 1990 (at least 177 published scientific studies on over 26,000 people) and 10 years of further extensive use in many countries. Most of this new information comes from conditions of free sale and is well documented.

In earlier reports it was suggested that studies of the safety of VLCD should be undertaken under conditions of use in the community. This information is now available from various studies and shows the considerable levels of safety of the modern nutritionally complete very low calorie (energy) diets.

During the SCOOP Committee meetings it was accepted that though the term very low energy diet is scientifically more accurate, the term very low calorie diet (VLCD) is so widely known and used that this is the term that should be adopted for the SCOOP Task 76.3 Report. In consequence we have also adopted this terminology.

Summary

 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).

The following more detailed summaries and conclusions were presented to the SCOOP Working Group:

 Section I           Overweight and obesity are rapidly and substantially increasing problems in all European Union Member States (Section 1).

Over the past decade the prevalence of excess weight has increased by some 50%. About 20% of the European middle aged are now obese and a further 30% or more are overweight (Section 1.1) Excess weightis now accepted as having reached epidemic proportions

Morbidity increases steadily from a BMI of about 24 (towards the upper range of normal) upwards. The problems associated with excess weight include not only serious diseases, but also psychological and social ills (Section 1.2)

Excess weight is strongly correlated with increasing mortality, so that at a BMI of 40 there is a greater threat to life than smoking 20 cigarettes per day (Section 1.3)

The economic cost of excess weight is substantial, with direct costs amounting to 1-5% of the health care costs in most first-world countries (Section 1.4)

The evidence supports the view that all effective and safe weight control methods should be readily available for all those who have excess weight.

Section II         The experimental studies and clinical experience reviewed here demonstrate that products with an adequate and specified macronutrient and micronutrient composition but an energy content below 800kcals per day (VLCD) are at least as safe as those of higher energy content (LCD)

  Special 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. (Sections 2.1& 2.3)

The studies reviewed here show that products with an adequate macronutrient and micronutrient composition, but an energy content in the range 400-800kcals per day (VLCD) are at least as safe as those of higher energy content LCDs at starting BMI levels down to 25 and finishing BMI levels in the normal range (20 to 25). (Sections 2.3 & 2.4)

The submission about safety is based upon the following data

:

Summary of the available published data on diets under 800kcals

As re-classified at the request of the Working Group

       NB.           The figures do not total because some papers do not contain full information.

       Several papers covering at least 500 subjects have been omitted because the full paper could not be examined.

 A full listing of these studies is given as Appendix I and a full bibliography for them is given as Appendix II.

Despite the fact that no deaths with liquid protein diets (PLD) have been identified since 1977/1978, it is still being suggested that experience with these diets have relevance. The information relating to LPD was re-examined and confirmation given to the Working Group that these have no relevance to current VLCD. (Section 2.3.1 &2.2)

Clinical studies have demonstrated that:

i)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)

iii)   There is no damage to the heart or other organs (Section 2.)

iv)   Various other concerns expressed in the previous reports on VLCDs (consequences of rate of weight loss, additional difficulty in weight maintenance and weight cycling) are no greater than with LCD (Section 2.5 & 2.6)

v)  The results with VLCD are as good, if not better than with the use of other methods of dieting (Section 2.6) In a group study in which there is good compliance, the rate of weight loss depends upon the energy level of the diet (Section 2.6).

vi)   The only way to achieve long-term weight maintenance is by a fundamental change in lifestyle. However the results achieved by such change after weight reduction by VLCD are at least as good as with those other non-invasive methods (Section 2.7)

vii)  Cholelithiasis is not a specific disorder of VLCD use and different formulations affect the incidence (Section 2.7). There is a requirement for essential fatty acids. If the essential fatty acids are derived from normal fat (which would require above 7g per day normal fats) this also provides sufficient fat to avoid cholelithiasis

Modern, nutritionally complete VLCDs are not only more effective than all other non-invasive methods of weight reduction but are at least as safe

Section III  Many recent studies have been undertaken which have established a clear understanding of the properties of VLCD

1)A thorough examination of body composition estimation has indicated that there is 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 methods are indirect estimates. This implies that the estimate is influenced by variation in formulae which are used for converting the observation to the estimate (Section 3.1).

ii)  Apart from technical errors in the estimation, attention is directed to physiological variations that can profoundly alter the results. Considerable attention to detail in the study is necessary (Section 3.1.5)

iii)  In consequence it is inappropriate to compare in the same chart, data derived by different techniques (Section 3.2.1).

iv)  The most widely used reasonably reliable indirect technique is hydrodensitometry and unless otherwise stated we have concentrated on data derived by this technique.(Section 3.1.5)

v)    Unrecognised analytical variation may explain the conclusions of Forbes on compositional changes during weight loss (Section 3.2.1)

vi)..The Keys (1950) Minnesota study has been quoted as confirming that fat free mass (FFM) loss is greater in individuals with less fat, who diet by any means. Re-examination of the data indicates that while this may be true in those at BMI levels less than 20, at these levels dieting is in any case un-necessary and contraindicated. It is irrelevant down to the least level (about BMI 25) at which dieting is justified. (Section 3.3)

vii)  The loss of lean body mass (protein) is inherent to 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 (Section 3.4 & 3.5)

viii) Re-examination of the old data and further new observations support the view peoposed by Garrow and others in the 1970s, that at all pre-dieting BMI levels between about 60 and 25, 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 (Section 3.5)

ix)                 Attention is directed to the fact that as loss of lean body mass is inherent in any weight loss, there is 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. (Section 3.7)

x)                  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 (about 90% of the available clinical data) have any merits.(Section 3.8)

Compositional standards.

From examination of the extensive scientific work available (Appendices II & III), and consideration of the various national and international regulations and codes of practice, the compositional conclusions currently in force for VLCD are:

Protein

Range of minima between 40-50g with a minimum nutritional quality as defined by WHO/FAO (FAO, 1991)

Carbohydrate

Either no recommendation; or in some regulations a range of minima for available carbohydrate between 40-50g.

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

This has been the subject of separate consideration and these 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 carbohydrate component of this should be included in the carbohydrate figure.

Energy

There is a range of minima between 400-450kcal. The energy value per se has no direct relevance and the minimum should be established based upon the energy provided by the defined minimum for the macronutrient recommendations.

Having re-examined the clinical and experimental evidence which we have submitted to the Working Group, we see no scientific reason for changing any of the above views about the compositional standards which we submitted in March 2000.

Section IV        There is substantial medical and scientific justification for modern nutrient complete formula diets with an energy value less than 800kcals per day :

     i)  It is widely accepted by scientists that formula diets are more effective than normal food based diets for compliance in weight reduction (Section 4)

ii)  There is no perfect single weight reducing method and a variety of safe diets is desirable to suit differing desires and prejudices. VLCD can have a significant effect on motivation and compliance in some people. (Section 4)

iii)  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 (Section 4)

Modern nutrient-complete formula VLCD have an important place in weight reduction

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

i).  The report endorses physiological and medical contraindications and precautions that have already been extensively published, but emphasises that these apply to all forms of effective weight reduction and not just to VLCD (Section 4.1).

ii).As with any weight loss diet, medical supervision is only necessary if there are medical complications (Section 4.2)

iii).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.

iv) .Continuous use of VLCD to the desired weight is preferable to intermittent dieting for both physiological and psychological reasons, and has no disadvantages (Section 4.3)

This report supports:

·      The need for any product claiming weight loss to demonstrate safety and efficacy.

·      Minimum compositional standards for all diets, including those in official reports, and in the media.

·      Advice that those dieting for more than three weeks by any method should seek medical advice.