The science of not eating vegetables
© 2014 Roy Benaroch, MD
It’s an epidemic. Many kids just won’t eat their vegetables. Eek!
Let me say up front that “not eating vegetables” really should be considered “One More Thing Parents Don’t Need to Worry About.” Yes, veggies are a good source of vitamins, and since they’re not calorie-dense they’re a great part of the diet for anyone who’s trying to maintain a healthy weight. But those vitamins are identical to the vitamins in fruit and inexpensive supplements. I have yet to meet any child who is genuinely unhealthy just because they didn’t eat their brussels sprouts. And I suspect just as many adults don’t eat veggies, either—and we don’t pick on them, and we don’t make them sit at their seats at the table watching their icky peas congeal. When faced with a child who doesn’t eat veggies, my inclination is to give the kid a break and worry about something else.
Besides, it turns out there’s some genuine science, here. Many kids who won’t eat vegetables may have a genetically-determined increased sense of taste, and they find vegetables too bitter to be enjoyable.
Researchers in Naples, Italy published a study titled “Taste perception and food choices,” looking at about 100 children, their parents, and unrelated control adults. They used genetic studies on saliva samples to look for variations in genes for the TASR38 bitter taste receptors, along with a standardized assay for bitterness taste sensitivity using 6-propyl-2-thiouracil. Kids and adults who were very sensitive to the bitter taste of that chemical were classified as “supertasters.” They also used food diaries to see what kids of foods the study subjects ordinarily consumed. There were several interesting conclusions:
- Childrens’ taste sensitivity was very different from both unrelated adults and from their own parents. Far more children than adults were “supertasters” who could easily taste even a tiny concentration of bitter chemical.
- Both children and adults who were supertasters tended to avoid eating vegetables, though the effect was stronger in children. Adult supertasters were more willing to eat veggies than child supertasters, perhaps because of habituation or social pressures, or just because they were willing to put up with bitterness—but they still didn’t eat as many veggies as the adults who were not supertasters.
- Supertaster status was associated with Body Mass Index in boys—in other words, boys who were supertasters tended to be more slender. None of the obese boys in the study was a supertaster.
- Supertasting children were less likely to be willing to try new foods, and the most taste-sensitive children tend to have the most restrictive diet with the least variety.
I like veggies—I grow a big garden every year, and I actually really like brussels sprouts (especially roasted.) I think eating veggies is a good idea for both adults and kids. But it’s certainly not a matter of life and death. If your children won’t eat veggies, it’s very possible that they are genetically built to be especially sensitive to bitter taste, and they just don’t like the flavor. In time, as they become adults, they may be more willing to try veggies—or maybe not. Either way, it’s probably not your fault, and it’s certainly nothing to worry about.