Despite extensive enquiry concerning the regular media as well as the scientific literature, we have not been able to find one single death which can validly be attributed to the use of VLCD within this medically compromised group in the past 22 years, despite extensive studies and free sale use by many millions of the population.

This can be contrasted with the extensive literature which accumulated rapidly and dramatically in the late 1970s and early 1980s during the brief period when "liquid protein diets" (which bear no relationship to current nutrient complete diets) were available. Although these tragic deaths associated with the use of liquid protein diets covered a period of only about 12 months in 1977, with no further problems after they were withdrawn from the market, they remain to this day a ‘spectre at the feast’. On several occasions matters relating to them have been raised by the Working Group and it is clearly important to put this spectre to rest.

2.2 Putting the spectre of liquid protein diets to rest.

Doubt has been cast from time to time on whether the daths in 1977 were indeed solely attributable to the use of liquid protein diets or whether some of these subjects had been provided with slimming diets of higher nutritional status. Accordingly at the request of the Working Group, an examination was made of all the available evidence relating to these liquid protein deaths in 1977 (Isner et al, 1979; the full report (dated 1979) of the bureau of Foods, Food and Drug Administration committee meetings (Contract FDA 223-75-2090), records of evidence submitted to the committee by the Center for Disease Control, 1979; Food and Drug Administration, 1977, Schucker & Gunn 1978, Sours et al, 1981; Federal Register, 1980; Federal Register, 1982; van Itallie, 1984) Additional to this we have examined the three papers which describe some of the original papers (Michiel et al, 1978; Singh et al, 1978; Brown et al, 1978): the papers which describe other deaths during therapeutic starvation for obesity (Cubberly et al, 1965; Kahan 1968; Spencer, 1968; Garnett, 1969) as well as the pioneer studies on PSMF in which there were no recorded deaths.  We have also examined the various AACE Positions Statements on Obesity up to the 1998 revision in which, from time to time comments appear on this problem. From this wealth of data and conjecture the following information emerges:

·                              Survival time was related to the BMI.

-         Despite the fact that there were over 200 commercial LPD in use in the 1976/1977 period in the USA which were used by a very substantial number of dieters in the BMI range 25-30 there were no deaths in this group.

-         All the deaths occurred in those over BMI 30.

-         There were more than 50 deaths attributed to LPD but only 17 of these were investigated. It is acknowledged that the other deaths may have had a different pathology – the situation of these is unknown.

-         Among the investigated deaths the survival time is directly related to the BMI in the above 30 range.

-         The fact that those in the 25-30 BMI range did not die is probably due to the relatively short use in those at the lower weight, but it can not be held that “fat is protective”.

-         In the above BMI 30 group it must be remembered that the total body protein before dieting was also substantially above the normal. If one of the problems with the LPD was a shortage of one or more essential amino acids, it follows that those with the highest protein (hence amino acid) reserves would survive longest.

·                              It is not true that ‘high quality VLCD’ were being used as a significant protein source.

-         No modern type VLCD were available commercially in the USA until 1980.

-         Some PSMF type non-commercial formulae of variable content were under study but the studies which used these higher quality protein did not lead to any deaths, though it is clear that the number of patients studies for over 2 months was so few that deaths would not have been predicted on the basis of the estimate of the risk of mortality from LPD (estimate some 1/700).

-         The dietary information within the quoted LPD reports was, by its nature all hearsay from relatives and friends and virtually none of it could be verified by independent evidence.

-         There are several references to the fact that “most consumed daily calorie intakes provided by 85 to 200ml… of hydrolysed collagen or gelatin estimated to supply approximately 300Kcal”. One of the original papers indicated that one patient took just 15ml per day over the whole period.

-         The amino acid analyses indicate that many of the tested products were virtually free of many of the essential amino acids.

-         Three women “added high quality protein to their” liquid protein diet. The amount is never stated but examination of their rate of weight loss compared with the remaining patients showed that the increase in calories must have been small. The conclusion of the USA committee was that the exact cause could not be determined (inadequate essential amino acids; ? electrolyte disturbances), that some supplementation with casein may have undertaken by a few people, but this does not amount to “use of high quality VLCD”.

-         There was only one man involved. The level of his use of the protein source (not a VLCD) other than LPD is far from clear. One report suggests that he merely supplemented – “all had used a LPMF diet as their sole source of calories for some months”, another says “he used a protein product that was reportedly of high quality”. It is of interest that this is the only autopsy that records “possible early infarct”.

-         Starvation had previously been shown to produce deaths of the type seen with LPD.

·                              Deaths were not only the result of self-medication without medical control

-         No less than 12 of the 17 patients whose deaths were examined were being treated by medical practitioners. It is frequently suggested – inaccurately that all were self-medicating.

-         A substantial proportion were alleged to have had regular electrocardiograms while they were receiving the LPD.

·      The deaths could not be attributed to protein losses in the heart being greater than those in other organs due to a more rapid protein turnover in that organ

-                     The “weight of the hearts….was decreased in proportion to the documented decrease in body weight”.

-                     There was no evidence of increased loss of heart muscle protein as a result of the different heart muscle turnover rate.

·                              Removing liquid protein diets from the USA market solved the problem

-                     From the 1980 FDA report and a further FDA report in 1982 it is clear that there were NO further deaths attributable to weight reduction once the liquid protein diets were no longer used despite the substantial free sale of a substantial number of properly formulated VLCD most at that stage with an energy content in the range 300 to 400 kcal per day.