Study: Fruits and Vegetables May Help Switch Off Genes Responsible for Obesity

Leafy greens, berries, and citrus fruits may attenuate the genetic risk for obesity.

A new study published in The American Journal of Clinical Nutrition is giving some weight to the old adage that “Nobody got fat eating too much broccoli.”

OK, fruits and vegetables contain calories and you could eat enough of them to gain weight, but what the study concluded is that fruits and vegetables may help to modulate genes responsible for obesity. If you’re particularly susceptible to obesity, more fruits and vegetables may lower your risk.

The research looked at the Body Mass Indices of 8,943 women and 5,308 men over a twenty-year period (five four-year intervals) and found that when consuming a similar nutritional content, folks were more likely to lose weight when consuming a high amount of berries, citrus fruits, and green leafy vegetables, regardless of their fiber intake or the glycemic load of the fruits and vegetables.

The study was a little more complicated than that summary, taking into account the participants’ genetic risk for obesity based on 77 BMI-associated loci. In short, some people have a higher genetic risk for obesity than others and it appears that more fruits and veggies can help to switch off some genes responsible for obesity. This is the same conclusion reached by a study of over 14,000 people that was published in The BMJ in 2018.


[Learn more: 7 micronutrients that are extra important for athletes.]


It’s worth emphasizing that this is a correlational study, so the conclusion that one’s intake of produce will affect your BMI isn’t rock solid, rather it suggests potential links. It’s also important to remember that one’s BMI isn’t necessarily a measurement of one’s body fat: many athletes will tell you that their Body Mass Index suggests they’re overweight or obese because they carry a lot of muscle.

The BMI can have some uses as a broad way of measuring a healthy weight, though it is imperfect. But since few people carry a lot of muscle and since it’s far more difficult to easily measure someone’s body fat, the BMI can be useful in some circumstances.

Wrapping Up

This research is an interesting look at the field of epigenetics. Some genes make some unhealthy lifestyles especially dangerous — for instance, if you have a family history of lung cancer, then smoking might be an even worse idea than it is for someone with no history of lung cancer. (To be clear, it’s a terrible choice for both of these hypothetical people, but some people are at a greater risk.)

Obesity may work in a similar fashion. Based on this research, while a healthier diet doesn’t eliminate these genes, it may help to “switch” some of them off. It won’t prevent obesity, but it may help to mitigate the risk. Add that to the long list of reasons why it’s a good idea to eat a lot of fruits and veggies.

Featured image via anghi/Shutterstock

Note: This article was updated on July 19th to reflect the fact to include the “Concerns” section. Thanks to Aubri Rote for pointing them out.

Nick English

Nick English

Nick is a content producer and journalist with over seven years’ experience reporting on four continents. At BarBend his writing more on nutrition and long-form content with a heaping dose of strength training. His underlying belief is in the middle path: you don’t have to count every calorie and complete every workout in order to benefit from a healthy lifestyle and a stronger body. Plus, big traps are cool.

2 thoughts on “Study: Fruits and Vegetables May Help Switch Off Genes Responsible for Obesity”

  1. Hi Nick,

    I appreciate your efforts in translating highly technical research for your readers. It’s tough to do, for sure. I’m concerned that your title (and some of your bold text) is misleading to your readers. This study was a correlation study, so it cannot be stated that intake of fruits and vegetables switch off genes (as that is a causal statement). In addition, this study was based on BMI which is a highly outdated measure of “obesity,” and this should be stated clearly in your article for your readers. Someone could have put on muscle mass via increased strength training, and their BMI would increase. Someone else could have lost muscle mass for various reasons and had their BMI go down. In addition, studies have shown that fat in the legs and thighs is protective against disease, while it is mainly visceral fat that is linked with increased disease risk. Using BMI tells us nothing of where an individual’s fat is.

    This kind of over-statement of research is rampant in nutrition and very confusing for readers. So, please know that misconstruing study results is very common. I am commenting on here in hopes to encourage more clear representations of what results from studies can and cannot mean. We have to do better for the general public. I urge you to consider some of these issues when reporting on your next article.

    • Hey Aubri, thanks for reaching out. I made the headline start with “Study: ” to note that this is what the study suggests, not that this is what has been proven, but I’ll modify it with a “may”. I’ll add in the concerns about the BMI, I appreciate your reaching out!

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