Entries Tagged 'Weight Loss' ↓

Look around the bookshops and read some of the reviews for the latest books on weight loss and there’s a new buzzword on offer. It seems the genes you inherit from your parents change the way your body absorbs fat and carbohydrates. Gone are the days when a one-size-fits-all diet would sell like the proverbial hot cakes (unsweetened, of course). Now we are into the idea of personalized diets with DNA kits and gene testing offered as the way of designing the most effective way for you to lose those unwanted pounds. Except, there’s no science to support any of these claims. Myths help separate you from your money. The truth remains boring and does not sell many books.

Let’s start with the facts. The science of genetics has been around for centuries. Farmers, sports fans and governments have been selectively breeding animals (and plants) for their taste, speed or killing abilities. The results can be seen everywhere you buy food, on the race track, in the police and military compounds, and so on. There’s nothing new in aiming to select characteristics to transmit through the generations. And that’s where the science stops and the science fiction takes over. Although some scientists can now identify individual genes that may contribute to different characteristics, there’s no such thing as gene splicing – no designer babies for us humans to order – and no proven link between any combination of genes and human body weight.

Human body chemistry stays the same no matter what genetic make-up you have. What does change, and sometimes quite dramatically, is behavior. If you travel back to a time when people ate less processed food in smaller quantities, you find most children grew up thin. Now look around. Children are surrounded by peers and authority figures who all eat large portions of unhealthy processed food and the children get overweight. This has nothing to do with genetics. This is socialisation in a country that eats too much unhealthy food. Continue reading →

As people have become more aware of genetics, a number of myths have been born. The most common is that the genes you inherit from your parents fix your body type and, no matter what you do, you cannot change it. This makes genetics a very convenient excuse when people are looking to explain why their latest diet is a failure. The reality is rather different. Genetics is science looking at the process that enables each new generation to inherit characteristics from the parental generation. People are deceived into believing that this science is very precise when researchers announce they have identified a particular gene responsible for an inherited disease. Science fiction stories have popularized the idea that parents will soon be able to order designer babies. Now the authors who are looking to sell their latest diet books have begun to push the idea that one size does not fit all genetic types. Rather, every individual has to assess their “genetic type” and then choose the most effective diet. The myth is being spread that basic human chemistry does not work in the same way across all human beings. “Experts” claim that people absorb carbohydrates, fat and protein in different ways. This difference can be measured by blood type, fingerprints and inside leg measurement, among other factors. Diets and exercise programs can be designed for individuals based on these factors. It seems science can help people lose weight.

Except, as in all cases, the myths are completely false. This is the old nature/nurture debate redesigned to fit into a newly recognized science. At present, there’s absolutely no evidence to show that the presence or absence of particular genes has any effect on obesity levels. No matter what the advertizers try to tell you, there’s no DNA/gene test to tell you anything useful about how to diet. The only evidence currently available that is relevant and of potential interest is that some genes do affect behavior including how quickly people feel full after eating. Obviously, if some people are slower to recognize their stomachs are full, they are more likely to overeat. Continue reading →