The most influential factors in terms of whether or not we gain weight can be attributed to our genetics, ethnicity and age. Some studies have shown that nearly 70% of a human’s body mass is genetically predetermined while the other 30% is only environmentally influenced. While this percentage is extraordinarily high, it demonstrates just how our weight can be strongly determined by our genetics. A closer look at two specific genes, lipoprotein lipase (LPL) and leptin, gives further insight into this link.
In the 1990s, there was scientific investigation into the gene lipoprotein lipase (LPL), which is an enzyme that is produced by fat cells to store calories as fat. LPL plays a critical role in transporting fats and breaking down fat-carrying molecules called lipoproteins. LPL is partially controlled by estrogen in females and testosterone in males. For females, fat cells in the hips, thighs and breasts secrete LPL while for males, LPL is produced by fat cells in the abdominal region. While fat cells in the abdominal area are often quickly released for energy, fat cells in the hips and thighs are used for long-term energy storage. This explains why it’s often easier for a man to lose his abdominal fat than it is for a woman to lose fat in her hips and thighs.
Recent studies have also shown that a protein hormone called leptin may strongly contribute to weight gain or obesity. Leptin is produced by fatty body tissue and believed to regulate fat storage. In other words, leptin is essentially the way in which your fat cells tell your brain that the energy thermostat is correctly set. Although it works as an internal thermostat, the problem lies in something called “leptin resistance,” which is similar to insulin resistance that is found in type 2 diabetes. Basically, if you are leptin resistant, your leptin levels are high but your brain doesn’t recognize it. Simply put, your brain is starved while your body continues to stay overweight or obese.
Genes can contribute to future obesity by affecting our appetite, our metabolism, our food cravings, our body fat distribution, even our emotional eating habits. Studies now show that children of obese parents nearly double their risk for obesity. However, being genetically predisposed to gaining weight does not automatically mean that you will become obese. Your eating habits and level of physical exercise continue to play a crucial role in maintaining a healthy weight despite any genetic predispositions.