• The published paper includes a graph (above) which shows what happened to each individual teenager - on the graph, each diamond represents one kid. We can see that 3 of the kids either stayed the same or gained weight even after 12 weeks of semi starvation. We can also see that most of the teens changed their % in BMI95th%ile by around 5-10% - this is not a huge change and it translates to very small changes in actual kg weight.

• We can see that at the 6 month point, more of the kids are actually heavier than they were before the starvation diet - 4 of them are now above the starting line. This reflects our bodies’ metabolic resistance to weight loss.

• We can also see one kid who has really lost a lot of weight. In weight loss research we call this a ‘super responder’. Clearly, this kids’ weight loss is very different to everyone else’s, and because this one person has responded in this way, their data changed the whole outcome of the experiment. In the conference presentation, weight loss between 12 and 26 weeks was ‘not sustained’, because the super responder was not included. But here in the published paper, thanks to one kid who may very well have developed an eating disorder, we now have ‘sustained weight loss results’.

• The published pilot study completely ignores the weight regain that happened to the majority of the kids in the study. It’s not discussed AT ALL, a trend which is unfortunately very common in weight scienceresearch. 

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Growth, Impact on Menstruation & Metabolism

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• Worryingly, the results show a significant reduction in height between 12 and 26 weeks. This was not discussed in the paper. This means that the teens' growth cycle is being interrupted. If a growing body is not getting adequate nutrition, the body will stop growing in order to compensate.

• Any impact of starvation on the teens’ menstrual cycle was not investigated. Given that 25 of the 30 were girls, this is staggering.

• Metabolic impact of starvation on the teenagers’ growing bodies was not measured or discussed in the paper.

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Health Markers

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• 28 of the 30 kids were reported to be ‘insulin resistant’ at the outset of the experiment. This was exactly the same after 6 months of semi starvation.

• Measures of cardiometabolic risk including cholesterol, blood pressure, and insulin resistance did not change after 6 months of intermittent starvation. Small changes in plasma triglycerides were reported, but these were in the normal range to begin with. A small increase in fasting plasma glucose occurred at 6 months, but overall no changes in insulin resistance occurred. 

• Expensive and complicated vascular structure and function (heart) measures were taken, of 9 vascular measures only one was significantly changed by 6 months - arterial wall thickness. Measures of these factors were not taken for all of the completers.

• The comments made to The Age newspaper regarding the effectiveness of the Fast Track pilot are not true. The teenagers in the pilot study did not see "benefits in their cholesterol, blood pressure, liver and heart function". At best, one aspect of a secondary marker of heart function improved at 6 months, but the majority of bio-markers were unchanged.

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Psychological Impact

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• Dietary restraint - a measure which can indicate disordered eating and presence of an eating disorder - significantly increased by 26 weeks. These scores were elevated to start with and became even higher as the starvation diet progressed.

• Although the paper reported ‘improvements’ in emotional eating and eating for external reasons, these scores were not unusual to begin with, therefore any reductions do not reflect a real life improvement, they are likely just reflecting the fact that the teens were eating less overall.

• Of 7 measured areas of quality of life, only 2 showed improvement by the end of the 6 months. Interestingly, the results showed that improvements in quality of life were more likely to happen for those kids who did manage to maintain their weight loss at 6 months, the ones who didn’t maintain their weight loss were worse off. Given that we know that all of these kids will continue to regain weight, it seems likely that their quality of life measures will worsen. However, the researchers will not follow them up long enough to find out.

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Adherence

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• We know that 9 kids dropped out and only 21 finished the whole 6 months. At 6 months, 5 of the completers had stopped doing the intermittent starvation days altogether. This means that nearly half of the group who started the diet had either dropped out or stopped doing the strict diet by 6 months. The paper did not provide a reason as to why the 5 ‘successful’ kids decided to stop doing the fasting. The paper instead talks about how many of the kids felt that they found the diet ‘easy and enjoyable’. This contradicts the actual data.

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Conclusions

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• In spite of objectively poor results, the authors merrily conclude that “IER is an effective dietary intervention which can lead to reductions in BMI and cardiometabolic risk.”

• This is a highly optimistic conclusion which does not reflect what actually happened to the teenagers, a frequent pattern for the Fast Track researchers. 

• The Fast Track researchers are not informing parents or teenagers of the likelihood of small weight losses followed by weight regain. This should be communicated clearly to parents and teens given the evidence from this pilot.

• Parents and teens are also not being told of the increased risk of eating disorder markers, such as dietary restraint. This should be communicated clearly to parents and teens given the evidence from this pilot.