Genetics is the science of study of heredity and deals with how various characteristics are transferred from one generation to another. The term “gene” has been given to the “unit of inheritance”. For years, scientists have been studying the miracles of genetics and the results of mixing various genetic backgrounds. Various questions have arisen that have fueled and driven scientists to continue their research in this field with evergreen efforts, amidst other issues.
A major issue in today’s generation happens to be the drift in increasing tendencies of obesity. This epidemic, however, was not present if we were to compare the population some years back. The number of obese people was strikingly low but now, the problem seems here to stay. Scientists have scratched their heads and blamed fast foods and high sugar intake as a likely culprit but there still seems to be a considerable number of people who remain thin, despite the general graph expanding linearly towards obesity. Furthermore, the incidence of someone being thin or not, often has little relevance to their diet and physical activity. Some people simply remain thin no matter how much they eat, whereas others keep on putting pounds despite watching their weight. A striking variation betwixt the two has raised heads.
While being questioned and examined, it has been observed that people often stated that their thinness or thickness ran in the family. For example, a thin person was generally accompanied by more thin people in the family, like thin parents. Whereas a person with greater body weight often had relatives in the same weight range. This peculiar observation become an area of interest. According to a study Colata and Gina in 2007, it was found out that there was an 80 per cent chance that the child of two obese parents would also be obese. Furthermore, the child of both normal weighing parents would not be obese in 90 per cent of cases.
The above study concluded stronger yet indefinite results. Hence, we can deduce that there is genetic involvement in fat distribution and weight but how and to which extent? An individual needs 2000 calories per day on average. However, the way this amount affects an individual varies. This is where genetics steps in. There are around 2500 genes that are linked to the incidence of high body weight. Genes like MC4R, ADIPOC, FTO, LEP and LEPR are well known for causing obesity. Obesity-inducing genes can be active from birth or start showing an effect after some time. A well-known genetic condition is prader-willi syndrome (PWS). In this condition, children are affected and become obese.
According to continuous scientific studies, these supposed obesity-causing genes are suspected to not only alter body’s normal physiology but also affect your eating habits. A person can have different paced metabolism or may be prone to develop an eating pattern without even being aware of it, all as a consequence of their genetics! Using the previous example of Prader-Willi syndrome (PWS), the child suffering from the condition becomes constantly hungry which leads to overconsumption of food. The child is bound to become obese. The child may even develop type II diabetes if the rate of consumption is not brought under control!
However, there have also been instances where individuals were found to have a certain obesity inducing gene but did not become fat. Perhaps the gene never got activated or perhaps the conditions were unsuitable to activate the gene. If the environmental factors are unfavorable, there might be some delay or absence of gene activation, and the individual may skip risk of obesity completely.
The mutual effect of all these factors come into play from the moment we first start breathing and it continues throughout our lives. However, this is where we are forced an interesting question, regarding those who are an anomaly to this genetic pattern: does genetic really has a role in determining body weight. The answer lies in the strength of the genetic influence. Genetic influence is pretty different from person to person. Research shows that genetics account for just 25% of the predisposition to be obese in some people, whereas in others, genetic predisposition is high as 70% to 80%. Having a rough idea of how large a role genes play in your weight may be helpful in terms of treating your weight problems.
Despite all the gaps in knowledge, it is safe to assume that genetics does indeed play a valid role in determining body fat and weight distribution. To sum things up, this occurs due to “genes” - the unit of inheritance. When a gene from one person, gene that controls the body fat distribution and weight, is passed on to another, the gene may or may not become active. The activity of the genes depends on the presence of favorable conditions. The genes, once activated, can hasten or slow down the speed of metabolism, and hence control body metabolism. This is why for those – even though they eat way less, they can put on more weight than a thin person. Or a person from an obese family may also become obese.