Every person is made from a complex biological system that was passed down to you through your family line. Everything that you put into your body must be filtered through your own person set of genes sometimes that works perfectly, and other times it can lead to a visit to the emergency room. Typically, it’s the daily things over a long period of time that leads to the most significant changes. Like anything that develops slowly it can be easy to miss that it is transforming and shifting the very foundations of you. I will lay out three examples of genes that can affect your metabolism and potentially lead to excess weight gain.
Obesity is an epidemic that in industrialized countries is associated with the number one leading cause of death. In the United States as of 2018 42.4% of the population was considered obese and those numbers are only on the rise. We have now entered multiple generations of families that have been obese and passed down hundreds of genetic factors that predispose children to obesity. Researchers are always looking at new genes that can be associated with obesity, but as discussed in previous chapters, the flexibility of the epigenome means that changing the expression of genes that are associated with obesity is of little consequence. You can always change your weight, through three main factors which include diet, exercise, and lifestyle. You can still have the genetic deck stacked against you, one example of this is what is known as the fat mass obesity associated gene or (FTO). If you have parents that are both obese, in other words with a body mass index (BMI) of 30 or above you have an 80% increased likelihood of being obese yourself. Before you go blaming mom and dad for your weight gain know that you are in full control of your own weight.
FTO is a gene that is only associated with obesity meaning that there are changes to the gene expression of you become obese. Just like there are changes to the rest of your body as you pile on the pounds the genome must follow to keep proper homeostasis. Luckily changes to the FTO gene are completely reversible if the excess weight comes off. With parents that passed down altered gene expression of FTO it leaves the child with an increased risk, but only if the child continues to perpetuate a lifestyle that will lead to obesity. If the child leads a healthy lifestyle with balanced nutrition, exercise, stress reduction, clean air, water, and good sun exposure, then the FTO gene no longer is expressed.
Obesity at the most fundamental level is a result of consuming more calories than are being burned. With anything that is involving every system of the human body, it quickly becomes much more nuanced and complex then calories in calories out. Along with genetic changes obesity brings changes to the endocrine system. Three key hormones in an obesity state create changes in metabolism these are insulin, ghrelin, and leptin. Insulin is a peptide hormone that is released from the pancreas when glucose is present in the blood so it can be absorbed by muscles and the liver to be stored as glycogen. In obesity the receptors for insulin to bind to are impeded by fat tissue, that literally get blocked by excess fat so glucose can’t be shuttled into muscles and the liver as efficiently. Creating what is known as insulin resistance and leading to high glucose levels that can turn into the clinical diagnosis of Diabetes Mellitus.