Genetics and Obesity 

Do you feel like you eat less than your thinner friends while struggling to lose a few pounds, BUT CAN'T? Do you wonder if the real problem might be in your genes? Have you ever asked yourself the question, "Am I genetically obese?"

A gene is the basic unit of heredity, found among DNA strands in our body, and responsible for the identifying characteristics and individual differences of our species. Simply put, our genes are in charge of who we are and what we look like. For example, if your mother has red hair, chances are you'll have red hair too.

We know that obese children usually come from obese families and an overweight child will most likely resemble one or more parents. If one of your parents is obese, you have a 40% chance of becoming obese also. If both of your parents are obese, your chances then increase to 80%.

Interest in the possibility that our genes might make us fat developed after studies were done to compare the food intake of mice and rats. The Zucker rat, a species of rat that tends to be overly plump, was compared with their thinner companions. Results showed that the thinner rats ate the same amount of food as the Zucker rat, and sometimes more, but remained thin. And so, the race was on to find the fat gene!

New research has identified certain genes on chromosomes that can cause rare disorders that lead to obesity, however, to date, a gene that causes obesity in the general population has not been found. But, researchers continue to believe that our fat is buried somewhere in our genetics. And so, as theories progress, if it's not a gene that's producing this up-and-coming generation of obese Americans, then could it be a defective gene? In other words, no one is supposed to get fat by smelling an apple pie, so perhaps there's an existing gene, one we already know about, that's not working properly? Maybe, but a defective gene that's producing those mounds of fat hasn't been found yet either.

Some researchers feel the answer may be found elsewhere in the body, other than in our genetics. Here are some of their theories:

Our Metabolism: Leptin is a naturally occurring hormone found in fat tissue. After leptin was injected into a strain of obese mice, they ate less food and lost weight. One U.S. company was so excited about these findings that they purchased the rights to a drug containing leptin. But the excitement was short-lived! It was discovered that obese people are not leptin deficient and may actually have more leptin in their tissues than lean people. However, a leptin gene has been discovered and is currently being studied.

Other substances being studied are NPY (neuropeptide Y), found in the hypothalamus, the part of the brain that regulates appetite, 5HT (5-Hydroxytryptamine) produced in the brain and is similar to amphetamine-type drugs like fenfluramine, CRF (Corticotrophin Releasing Factor) also produced in the brain that causes weight loss by reducing appetite, CCK (cholecystokinin) which helps to block food intake and induce satiety, and bombesin which helps decrease appetite. These are just a few to give you some idea of the amount of research that's going on, but so far, nothing doing in the metabolism category.

Physical Activity: Studies show that obese people are less active than thin people. Perhaps our fat bodies just need a little bit more exercise and then we'd all slim down?

Social and Environmental Factors: Our society evolves around food. Food is everywhere. Research shows that when food is placed in front of people who are not hungry, they will eat. In studies with thin rats, high fat foods (candy, nuts, and meat) were made available 24 hours a day. And what do you think happened? You guessed it! The thin rats became fat rats! Could the solution be that simple? That maybe some of us just need to stop eating so much?

The search continues for the causes of obesity. But to date, there's no clear answer yet to the question, "Am I genetically obese?"

Since research has not made a discovery that will allow us to eat all we want and stay thin, where does that leave us overweight people who insist we should be able to do so?

Some advice: If you're waiting for the fat gene to be discovered in lieu of starting a diet plan, you may have an eternal wait. It's possible that the fat gene will never be found because there may not be such a thing lurking around in our DNA. Although that may be good news for the fad diet industry who have made billions of dollars on our inability to decrease our food intake, it's gloomy news for those of us who want to wolf down the high calorie, high fat foods and then take a pill to make it all go away, and for many of us following high protein fad diets who haven't figured out yet that you can't lose fat by eating fat!

And so, perhaps the question is NOT, "Am I genetically obese?" The real question might be, "Do I look like my mother because I eat like my mother?"

NUtritionTipS
-Hypothyroidism is a disease of the thyroid gland that causes weight gain. It's estimated that 3% of the population have this disease. Hypothyroidism can be easily diagnosed by a blood test.

-Dietary fat is not used as energy. Instead, the fat you eat is metabolized directly back to fat storage in the body. Body fat is used, or burned off, as an alternate energy form when glucose or carbohydrates are not available or during aerobic exercise. In other words, all that fat from the butter, fried foods, and mayonnaise you're eating goes right back to your body fat stores.

-If you're trying to lose weight, avoid fad diet plans that advocate high protein, high fat foods which are also high in cholesterol. Why? You may lose weight on these plans if you decrease calories, but your LDL's will increase putting you at increased risk for a heart attack.

Where do you get your nutrition information? Most states now have licensure laws for Dietitians and Nutritionists. Be sure your nutrition advisor is "Licensed" by the State as a Licensed Dietitian (LD) or Licensed Nutritionist (LN), or in states that don't have licensure laws, a Registered Dietitian.

CarboH, Inc.
Barbara Herondorf, L.D.

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