Everyone is always looking for an excuse to be lazy. The most recent example of this in the weight loss industry is the discovery of the "fat genes." Experts claim that these genes are source of obesity in individuals who carry them.
Personally, I believe these discoveries will do more harm than good to those unmotivated few who happen to be overweight.
However, there may be some scientific good that comes out of all this. So, this week will be dedicated to reviewing the genes that science claims to be the cause of obesity.
One of the newly discovered gene codes is a substance called "leptin," referred to in the literature as the "ob gene." Leptin helps to regulate appetite and activity level. The study indicates that the strain of mice that lack the leptin gene have insatiable appetites and become very obese (hence the "ob").
Unfortunately, studies done on thousands of obese humans have found no people with particularly low levels of leptin. In fact, the genetic defect has been found in only two people. Thus, this "fat gene" has little promise for fat loss drugs or supplements.
The next of the genes recently found, helps in controlling how the body produces and uses fat: lipin. The gene's researchers claim that this finding will provide a new target for therapies to control obesity, diabetes and other weight-related disorders.
"Findings suggest that differences in lipin levels may play a role in why some people are more prone to weight gain than others who consume the same calories," said principal investigator Karen Reue, Ph.D., a professor of medicine and human genetics at the David Geffen School of Medicine at UCLA.
When fed a high-fat diet for six weeks, mice with elevated lipin in their fat or muscles showed double the amount of weight gain compared to normal mice.
When the level of lipin was increased in the muscle, the cells burned carbohydrates before fat. However, when lipin is absent, the cells burn fat before carbohydrates. With its limited study, lipin has shown more potential than leptin but much more needs to be known about this gene until it really becomes useful.
Another potential "fat gene" that stimulates hunger has recently been discovered. This gene, called GAD2, was determined to be a cause of overeating and obesity among many people worldwide. A European team of scientists carried out the research on about 1,200 people. The study showed that the gene acts by speeding up the production of a chemical in the brain. When that chemical, known as GABA, interacts with another molecule in the brain, people feel a craving for food.
The researchers said that some people may have a more active form of the gene and suggested that the overload of GABA drives the person to overeat and become obese.
Drs. Spiegelman and Heidi Camp from Harvard and Pfizer, respectively, have determined that the gene which encodes the PPARgamma protein is responsible for fat cell development. These two research groups have discovered that PPARgamma is responsible for the transition from pre-adipocyte to fat cell.
A hyperactive form of this protein could lead to obesity.
There have been many other genes located for obesity, but these mostly code for beta-adrenergic receptors.
The body regulates energy by releasing chemicals to stimulate them. These receptors essentially act like a switch to burn fat. If the receptors are broken or deformed, the switch only partially turns on. A Native American tribe has been studied where the faulty gene has been found in abundance.
Individuals with one faulty gene generally have base metabolic rates (BMR) about 50 calories lower than expected, while two faulty copies have an 80 calorie deficit, which results to about five pounds gained per year.
If you find that you have a "fat gene" or two, let that be motivation to work a little harder than the average Joe. Fifty to 80 calories a day is hardly going to stop you from making progress if you're training hard and watching your diet. If diagnosed with one of these genes you should tell science to bite the big one and hit the gym.
