When it comes to weight loss, we often hear "Calories out must exceed calories in." But this explanation is just too simplistic. Besides, it does not account for many very real variables that have nothing to do with will-power and self-control.
In fact, the weight bared at a physical appearance might come down to how DNA is embedded at a cellular level. Because from tall or short to freckled or not, we come in myriad packages with variable features. Most of which of these characteristics are determined before we ever draw breath.
Genetics may also play an important role in the development of obesity. What's more, solid research is helping us understand despite similar efforts to lose weight, why some individuals yield results differently from others.
Moreover, researchers have identified specific combinations of genes that appear to correlate with predispositions in which we carry body fat or build muscle. They have also patterned how some individuals have greater success with exercise regimens.
But do genetics really determine weight? Find out if genes or environmental factors are to blame for weight gain.
Is Weight Genetic or Environmental?
Weight status is undoubtedly complex. However, overweight and obesity can be the result of compounding risk factors, including:
• Dietary patterns and excess food intake
• Physical inactivity
• Certain health conditions and diseases
• Some medications
• Education and skillsets
• Food availability and promotion
• Psychological factors
According to the Centers for Disease Control and Prevention (CDC), though, genetic changes in human populations occur too slowly to be responsible for the obesity epidemic. But this does not discredit research showing slim people have a genetic advantage.
Research term found several common genetic variants already identified as playing a role in obesity. But they also found new genetic regions involved in severe obesity and some involved in healthy thinness.
"This research shows for the first time that healthy thin people are generally thin because they have a lower burden of genes that increase a person's chances of being overweight and not because they are morally superior, as some people like to suggest," says research team lead Professor Sadaf Farooqi. "It's easy to rush to judgment and criticize people for their weight, but the science shows that things are far more complex. We have far less control over our weight than we might wish to think."
Is There a 'Fat Gene'?
A gene is the basic physical and functional unit of heredity, or what has been inherited from family. They are made up of DNA, varying in size from a few hundred DNA bases to more than 2 million bases! The Human Genome Project has estimated humans have between 20,000 and 25,000 genes.
Every person has two copies of each gene, one inherited from each parent. Most genes are the same in all people, but a small number of genes (less than 1 percent of the total) are slightly different between people. While these differences might be small, the genetic makeup is responsible for everyone’s unique characteristics.
But there is no single gene responsible for determining body weight. In fact, more than 400 genes have been identified! Most of the evidence lies in genetic mutations tied to the hormones leptin, ghrelin, adiponectin, and neuropeptide Y. These are known to influence appetite control and metabolism.
Some of the most common and newer genes tied to weight and obesity include:
• FTO: The FTO gene was the first of its kind to be associated with obesity. The link between the gene and the risk of being overweight or obese has been confirmed in many populations.
• Iroquois homebox gene 3: Simple known as Irx3, this gene is claimed as the "new leader on obesity genetics." A genetic deficiency in Irx3 expression can lead to 30 percent weight loss, designating the gene as a factor of body mass and composition.
• Ankyrin-B: According to newer research, variants in ankyrin-B could be causing millions of Americans to put on pounds through no fault of their own. This is coined as "fault-free obesity." An animal study shows the gene causes fat cells to suck up glucose faster than normal and double in size. Eliminating or mutating, changing the gene, ankyrin-B allowed glucose to flow into the cells more quickly than usual.
• Pannexin 1: Or simply Panx1, Pannexin 1 is a gene that regulates fat accumulation and obesity. The gene regulates fat accumulation in life and can lead to a higher risk of obesity later in life.
• CYP17 and CYP19: The expression of CYP19 and CYP17 is associated with leg length, weight, and BMI. More specifically, CYP17 gene expression may influence growth during childhood and adolescence. The CYP19 may be linked to concurrent measures of weight and BMI.
Again, there are hundreds of genes linked to weight. But recognizing these genes allows researchers to consider and develop effective methods to mitigate against additional weight gain. For instance, weight is majorly impacted by the foods we choose to eat.
That being said, health experts encourage to not use genetic cards we were dealt with and family histories as a free pass. Instead, play the game called life with our best hand forward. Because while genetics play a role in weight, overweight or obesity is not a finite destination.
When it comes to developing healthy behaviors, the sooner the better. Whereas families cannot change their genetic predisposition, they can change the family environment. Encouraging healthy eating habits and physical activity in early childhood is an approach to target childhood obesity.
Truly, making healthy lifestyle choices can help trump genetic barriers tied to weight. Healthier habits can also reduce the risks of heart disease, insulin resistance, type 2 diabetes, cancer, and other health conditions.