I have now read the pdf on the science behind the DNA diet. I am now thinking that there may be something to it but that something is a little underwhelming and referring to advice based on it as “individually tailored” is a bit of a stretch.
It starts with a discussion of the genes involved in weight gain and how variations in the genes can effect weight loss. For example:
A group of obese, non-dibetic patients analysed before and three months after a lifestyle modification program consisting of hypocaloric diet (1520 kcal/day) and aerobic exercise three times per week … showed that carriers of the Thr54 allele (compared to the wild-type 54Ala/Ala homozygotes) failed to have a significant reduction in fat mass, LDL-chloresterol levels, and lepin levels
This is typical of how studies are reported – numbers are usually not given, nor frequently are explanations as to how confounding factors are allowed for. However, references are given. It might be a worthwhile long term project to track down and read all these references. The reference for the above study is ” deLuis DA, Aller R, Izaola O, Gonzalez Sagrado M and Cond R. Influence of ALA54THR Polymorphism of Fatty Acid Binding Protein 2 on Lifestyle Modification Response in Obese Subjects. Ann Nutr Metab 50: 354-360, 2006″.
On the basis of this we are told that there are five major classes of phenotype “supported by at least five positive studies”.
A clinical study at Stanford University is cited as validation of the weight loss DNA test:
A clinical study was carried out to test the effectiveness of the Weight Loss DNA test. This Study was conducted by representatives of the laboratory and the prestigious Stanford University
These results were presented at a conference by Dr Mindy Dopler-Nelson (then a post-doc at Stanford, now an Assistant Professor at the University of Massachusetts) in March 2010.
The original study was of 311 women randomly assigned to one of four diets. They were asked to give DNA samples. Not all did so:
Among the women from the original study who agreed to provide DNA samples, 31 had been in the Atkins group, 32 in the Zone group, 34 in the LEARN group and 36 in the Ornish group
Dr Dopler-Nelson is quoted as acknowledging that this was a relatively small trial and the findings need to be confirmed in a larger trial.
In conclusion, BioClinics analysis of the research suggests (according to them) five phenotypes. The study said to validate the research covers 133 women on four diets and the presenter of this work reckons the results need to be confirmed. This all suggests that there is indeed a genetic basis for which weight-reducing diet might work best for the dieter but it is not conclusive and in any event hardly justifies claims in the press of diets and exercise regimes tailored to the individual’s DNA.