Why is it that some people eat anything they like and never put on weight and yet others restrict their calories exercise regularly and yet still remain overweight? The answer could be in their genes.
Current research has found that the most common reasons for obesity are results of how our genes work together and their interactions with the environment (Smith, 2015). Each of us has a unique set of DNA inherited equally from our father and mother. I have recently had my DNA tested and the reports for me were quite surprising! I have quite a few genes that predispose me to obesity – hence my lifelong battle with the bulge. It is the combination of these genes determines how our body acts such as “urging us to eat more, manipulating our metabolism, organising our fat-burning potential, mobilising the fat and our fat burning potential” (Smith, 2015).
Epigenetics overlays this structure as it is the interaction of environment on the DNA either turning it on or off -gene expression (AEpiA, 2015). Ideally a person would want to switch on the genes that assist us with body weight regulation and switch off those that deregulate the normal homeostasis of weight control.
Epigenetic influences begin as individuals are developing in the womb. Maternal nutrition during pregnancy has been found to affect the phenotype of the unborn child by means of epigenetic regulation of genes (Burgio, Lopomo, & Migliore, 2015). Obesogens such as the flame retardant BDE-47, BPA in plastics, PAH found in spray cans, and others have been studied by looking at the effects on obesity following exposure in mice. It is now considered irrefutable that early life exposure to these can alter the epigenome over multiple generations (Stel & Legler, 2015).
Therefore mothers need to be acutely aware that what they ingest, apply and the environment around them has subsequent effect on the developing foetus with long lasting consequences. We are very careful to regulate these factors in our house (we cant help outside or other places though).
Methylation and histone modifications are some of the known regulators of gene expression. They could been seen as the conductor of the body’s orchestra signalling to genes when to play (produce enzymes) and when not to (Smith, 2015).These are thought to play an integral part in the development and predisposition to metabolic diseases including obesity and type 2 diabetes (Kirchner, Osler, Krook, & Zierath, 2013). Methylation has recently been studied and it has been discovered that this process has the ability to turn genes ‘off’. The exact role is yet unknown but it also appears significant in embryo development (Phillips, 2008). Knowing about one’s DNA would identify genes that affect weight regulation and methylation needs and assist with weight management.
Some of the genes associated with obesity include FTO which affects 40% of the population. This genes signals when to stop eating. It causes people to overeat. Found in 25% of the population MC4R is known as the snacking gene, it affects the hypothalamus receptors that detect when energy levels are low signalling to the body to eat. I have this gene and need to be mindful when eating and regulate the amount of food that I consume.The LEPR gene is a regulator of leptin. It reduces leptin control. By knowing that you have this gene you might employ strategies to limit your food intake rather than relying on the ‘full’ feeling. I have used the Changing Habits 4 Phase Fat Elimination diet to regulate my leptin responses and to lose 30kg.
Emotional eating genes include DRD2, and OPRM1. These affect the reward systems of the brain and can have a role in food addiction. Metabolism is known to assist with weight management but what if you have the genes ADIPOQ and UCP2? These genes are known to slow metabolic rate and how efficiently an individual uses energy from food. There are many more genes that affect the way that we respond to food and process it in our body (Smith, 2015). Genes play and integral part in our relationship with food and subsequent body shape.
So, weight management is not just a matter of self-control. DNA switched on and off through the epigenetics plays a role that has only just been recently realised. People who understand their genome are able to put into place some life skills to assist with weight management. It is important to know your own individual DNA blueprint to tailor your lifestyle and food choices accordingly as this is where ‘off the shelf’ diets will often fail.
AEpiA. (2015, January 5). So what is epigenetics? Retrieved from Australian Epigenetics Alliance: http://epialliance.org.au/what-is-epi/
Burgio, E., Lopomo, A., & Migliore, L. (2015). Obesity and diabetes: from genetics to epigenetics. Mol Bio Rep, 799-818.
Kirchner, H., Osler, M., Krook, A., & Zierath, J. (2013). Epigenetic flexibility in metabolic regulation:disease cause prevention? Trends Cell Biol, 203-209.
Phillips, T. (2008). The Role of Methylation in Gene Expression. Nature Education, 116.
Smith, M. a. (2015). Gene Genius. Sydney, Australia: Harelquin Enterprises.
Stel, J., & Legler, J. (2015). The Role of Epigenetics in the Latent Effects of Early life Exposure to Obesogenic Endocrine Disrupting Chemicals. Endocrinology, 3466-3472.