I'm sure we've all heard a coworker, relative or friend talk about their failed weight loss attempt(s) due to their genetics. Whether obesity runs in the family, they have a ridiculously slow metabolism or they're just big-boned, many failed weight loss attempts seem to all come down to genetics. But Uncle Todd never bothered tracking his calories. And Sue from the office couldn't stick to her diet; it was her sister's birthday party and fried chicken wings were half off. Surely that has nothing to do with genetics, has it?
Well, maybe a little. But not as much as you may think. If your DNA decides you're the lucky contender who gets to exhibit a certain variation of the APOA2 gene, those fried chicken wings will affect you a lot more than the slim, young gentleman on the barstool to your right if they were fried in saturated fat.
Recent research also suggests that one's genetic makeup determines their body's "desired" weight range. Meaning, if you go below a certain weight, it'll be easier than usual to gain weight. Whereas if you go above a certain weight, it'll be easier than usual to drop back down. This can be pesky when your body likes to be 140 pounds, while you want to be 130.
However, one thing we often hear regarding genetics and weight loss is the curse of the slow metabolism. We often hear of how so and so just couldn't lose weight due to their slow metabolism. Here's the thing. Studies continue to show that increased weight leads to an increased metabolism; if you have a lot to burn, your metabolism works on burning it by stepping things up a notch. This is arguably the most popular myth regarding genetics and weight loss, but it simply isn't true.
The biggest key factor when it comes to changing and managing one's weight all comes down to calories in - calories out; eating less (or more, if trying to gain weight) calories than you burn. This goes for everyone, no matter the genetics. If your genetics put you in a situation where you're gaining weight eating as many calories as you burn, you're only going to gain more by increasing your caloric intake. A lot of people with "bad genetics," when asked about the amount of calories they consume, may not have an answer because they never thought to check. Bad genes, when it comes to losing weight, are fewer and further between than what many people believe.
So, yes. Genetics do effect weight gain, weight loss and weight management. But not by a whole lot. If you do happen to have the less desirable variation APOA2 gene, saturated fats can throw your all your work down the drain. But this can be solved by not eating trans fats. And having a genetic makeup which prefers your body stay overweight won't have as drastic an impact as you may think. Nobody's body naturally stays at 300 pounds due to genetics. At the end of the day, eating less calories than one burns will work for the overwhelming majority of people, despite their genetic makeup.