Most fruit lovers will agree that one of the great things about summertime is the variety of fresh fruit found in local grocery stores and farmers markets. Because of their delicious sweetness, most children are naturally attracted to fruit. Pediatricians are often asked by parents: “Can you eat too much fruit?” For the person consuming an otherwise normal diet, Markham Heid says the answer is, “Probably not”:
“There are some people out there who are fruitarians, and from what we can tell they’re perfectly healthy,” says Dr. Robert Lustig, a neuroendocrinologist and professor emeritus of pediatrics at the University of California, San Francisco. (However, full-blown fruitarianism is so restrictive that it has been linked to nutritional deficiencies in some people, and may be unsafe for children and those with certain medical conditions, like diabetes.)
But for healthy adults, experts say that eating lots and lots of fruit is unlikely to get you into trouble, as long as it’s part of a normal diet.
We have examined Dr. Lustig’s work before on The PediaBlog. The pediatric endocrinologist has called sugar “toxic” due to its impact on the body’s metabolic functions, blasted America’s fixation on processed foods, and broken down the typical American diet into its health-destroying components. Whole fruits contain both soluble and insoluble fiber which helps slow the digestion of the naturally-occuring sugar in fruit (fructose), minimizing the jolt of sugar one might experience by drinking sugar-sweetened beverages and fruit juices, which are both deficient in fiber. Fiber also helps the fruit-eater feel full faster:
Along with helping to control the absorption of fruit sugars, the combination of soluble and insoluble fiber in whole fruit also “greases the wheels” of digestion, Lustig says. Your gut signals to your brain that you’re full once the stuff you’ve eaten reaches your ileum. And because fruit fiber helps food molecules reach your ileum sooner, you tend to feel full more quickly after eating fruit than if you’d eaten foods lacking fiber. As a result, “fruit consumption is self-limiting, so the chances you will overeat fruit are relatively low,” he says.
A run to the bathroom with a bout of diarrhea may be in store in case we don’t get that fullness cue from our ileum, warns Heid, who also reminds us that all fruits are not created equal:
Some fruits may be better to indulge in than others. Berries, though pricey, have been linked to both improved heart and brain health. And while some online sources give pineapple, bananas, and other so-called “tropical” fruits a bad rap—mostly because they’re higher in sugar than many domestic fruits—Lustig says they also tend to have proportionally high amounts of fiber, and so aren’t inherently dangerous.
There’s only one fruit he says may be worth watching out for: grapes. “Grapes are outliers in terms of their sugar-to-fiber ratio,” he says. “They’re basically little bags of sugar.” While he doesn’t recommend avoiding grapes entirely, they’re not the best fruit to overeat.
If you love whole fruit, there’s little evidence that indulging in it—even a whole lot of it—is bad for your health.
Unless you are a strict fruitarian or your doctor advises you otherwise, adding plenty of fruit to your diet is a positive step to good health and a healthy BMI.