The Ten Commandments of Weight Loss - V

V - Your Mother's and Your Father's Genes Count

As you probably guessed or knew already, inherited tendencies to gain excessive weight are real. Ignoring them does no good, so we better learn to accept them and find proper ways to counteract them. This article will help you do that.

Not too long ago, the general perception was that overweight and obese people had nobody else but themselves to blame for their excessive weight. It was them, after all, who had to finish all the cookies on the plate. They were the ones making sure the fridge was always stocked with ice cream, and if they ate it in the middle of the night, they could not blame anybody else for waking them up. And when they hid chocolate and candy under their pillow, what else were they expecting than love handles and bulging bellies, right?

Today, we know a lot more about inherited factors that lead to excessive food/caloric intake and weight gain. A rapidly growing body of scientific literature paints a picture that shows at least two things:

1. Many obese people have a significant genetic propensity to gain weight.
   • There are over 50 genetic loci associated with obesity phenotypes. You may think these are a lot of mutations to worry about, but they actually account for only 2–3% of the inherited contribution to obesity risk.
   • Multi-gene interactions are thought to have an even greater influence on the risk for obesity, but this area is still very much a work in progress. The idea here is that while individual mistakes or mutations in single genes may have minor effects on weight gain, multiple such damaged genes can have synergistic effects, with a resulting weight gain that is much greater than the sum of the effect of each individual gene.
   • Epigenetic changes/differences appear to play a significant role in the inherited tendency to obesity. Again, the specifics will need to be worked out. On a mechanistic level, the way this works is through certain molecules that are intertwined with our DNA and have the power to silence genes. The ticker is the behavior of these molecules can be altered by the environment, and can even be inherited from one generation to the next, and ofter persist through multiple generations.
2. Our bodies are designed to hold onto gained weight through a variety of redundant mechanisms that are literally wired into our brain. Incidentally, this is one of the main reasons there has been so little progress so far in developing weight loss drugs; blocking one pathway that leads to overeating does not help much, as there are multiple other neuro-endocrine mechanisms that can by-pass it.

If you think about it, for most of known history, humans have lived in an environment where drought, floods, pests, wars and other adverse conditions have made it so that famine posed a much higher risk than food abundance. A brain that can maximize chanches of survival by keeping on weight rather than shedding it, in such an environment, makes perfect sense from a design point of view.

Is There Hope For Those Born With Inherited Tendencies to Gain Weight?

The answer is an emphatic YES! But it is a qualified yes. Let me explain.

It may help to think about this by examining other undesirable/unhealthy inherited traits. For example, somebody may have been born with a propensity for aggressiveness, but that doesn't mean they have no control over their temper or actions. They just need to spend more energy and time learning how to keep their impulse to act in an aggressive way under control, compared with somebody who does not have this trait. Similarly, a person born with a genetic makeup that causes them to gain weight even when they think of food (OK, I'm exaggerating here) need to pay extra attention on what and when and how much they eat and spend more time planning and engaging in physical activity.

I have many patients and some friends whose bodies like to put on weight, yet they have mastered ways to counteract it. One extreme case is a friend, Don, who confessed to me a while ago that the only way he can keep his weight from going up is to run and walk at least 20 miles a week. And he has been doing just that for several decades now. And his weight is fine.

Are There Genes That Can Make You Lose Weight?

This could be the topic of another article, but with the risk of giving a simplistic answer, yes, there are people out there that are born with a mix of genes that seem to protect them from obesity. I will leave it at this, as chances are, if you are reading this, you are not one of those lucky people, and I don't want you to start disliking your parents :-)

There is one more thing I wanted to say for those who do not have to struggle too much in this area. Please understand this is a very uneven battlefield for a lot of folks, and we have to acknowledge and salute the efforts of those who are born with weight unfriendly genes.

Dr. Gily Ionescu MD, MS.