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My mother once said to me, “If it makes you feel any better, I’ve always had big thighs, too.” Well, I can’t say that made me feel better, especially since I hadn’t even mentioned my thighs in that conversation, but suddenly something became very clear. Money and worldly goods are not the only things we stand to inherit from our families.
Inheriting Fat
Maybe you eat too much. Maybe you don’t exercise enough. Maybe your family is inclined to indulge in cultural food fests, or you’re so busy you only have time to eat fast food. But you also may have inherited your weight issues from one or both of your parents.
If fat runs in your family, you have a much better chance of being fat yourself than someone with lean relatives. But is fat in your genes or in your environment? Did you inherit a tendency to gain weight or did you just inherit bad eating habits? Likely as not, you got a little bit of both.
In the scientific community, it is well accepted that body shape and body weight are largely a function of genes, much like height, eye color, and a propensity for certain diseases. Genetic researchers acknowledge that lifestyle factors such as poor eating habits, and lack of physical activity, along with psychological issues such as unresolved emotional problems, social pressures, and stress, all contribute to weight problems. But none of these factors are as powerful as individual genetics. Genes also affect your propensity to gain weight by helping to establish your individual metabolic rate, which is the number of calories you burn in a given period of time.
The good news is that you don’t inherit fatness. You only inherit a tendency to become fat. There’s a difference, because it’s a lot easier to do something about a tendency.
The Genetics of Obesity
In 1994, news spread far and wide that obesity researchers at Rockefeller University in New York had discovered a gene that, when damaged, causes mice to get fat. They named it the OB gene, short for obese gene. The OB gene is found in fat cells. Its job is to make a hormone-like protein called leptin, that sends a signal to the brain that lets the mouse know when its fat cells are full so it will stop eating..
Obese mice have defective OB genes that forget to make leptin or produce too little of it, so the signal to stop eating doesn’t get sent. Oops! Twenty-five pounds of cheese later, you’ve got one fat mouse.
You are not a rodent, but scientists knew they could use the mouse gene to locate a similar gene in humans. And they did. Then they tested mice to see what would happen if they were given leptin supplements. The mice ate less and lost weight. Leptin also increased their metabolic rates. Of course the scientists were very excited and hoped to find the same results when leptin was given to humans. It soon became obvious, however, that obesity in humans is more complicated than in mice.
When obese humans were injected with leptin, they too lost weight, but only if they carried the defective gene. This research was pivotal because it was the first to show that human obesity can have a genetic basis. But researchers discovered that a faulty leptin gene is extremely rare, and if you’re not overweight for this reason, leptin supplementation won’t help. It is now known that many genes play varying roles in regulating body weight, and scientists worldwide continue to investigate how genes work to increase the risk of, and provide protection against, obesity. Other genetic research focuses on the link between the neurological system and addictive, impulsive, compulsive and other unhealthy human behaviors that can play a role in weight gain.
Genetic discoveries are probably most exciting to scientists and to pharmacists who hope to develop new weight loss drugs that might work by fixing all these damaged genes. New treatments for obesity will be coming down the pipeline, but it will be some time before anyone knows how to medically patch up broken genes and make them work properly, and without causing side effects.
All in the Family: What You Can Do
You don’t have to fulfill your fat destiny. Coming from a fat family makes it easier to gain and harder to lose weight, but it’s not impossible for you to get fit. If you live with your family or spend a lot of time eating with them, and you want to improve your diet, enlist their help and support.
Figure out what you want your parents or other family members to do. Do you want them to start cooking differently? Do you want your brother to stop leaving bags of potato chips on the counter? You can ask for changes, but don’t blame! Your weight issues are your own. You just want to explain your goals to your family and ask for their support. Tell them specifically what they can do to help. They may want to join you in the effort, or not. All you can do is make suggestions.
There are a few ways families can cooperate to break old food and fitness habits and introduce new ones, together:
• Shop together. If everyone goes to the supermarket, everyone has a chance to pick out their own favorite healthy foods and to remind each other not to buy junk food.
• Cook together. Share what you know about low-fat cooking with the rest of the family and experiment with new recipes.
• Encourage reasonably-sized food portions on individual plates, rather than “family style” eating, where serving bowls are passed and everyone helps themselves.
• Instead of dessert, take an after-dinner walk together.
• Encourage family activities that get everyone moving, even if it’s just throwing a ball around the yard. Take exercise classes together and plan hiking, biking or other activity-based family vacations.
