Consuming a glass or more of 100% fruit juice daily may be associated with weight gain in both children and adults.
According to a new study published in the medicaljournal JAMA Pediatrics, drinking 100% fruit juice might lead to weight gain because of the high levels of sugar in them. The study also says that these drinks also lack the fiber found in whole fruits, causing lower satisfaction and increased energy intake.
In children, each daily 235-milliliter, or 8-ounce, glass of 100% fruit juice was linked to a 0.03 increase in body mass index (BMI), while in adults, the same amount of juice was linked to a 0.02 increase in BMI.
The study looked at 42 studies, 17 about children and 25 about adults, then researchers combined all the data to analyze it as one big study.
While 100% fruit juice can provide some vitamins and nutrients, it shouldn't replace whole fruit or be consumed excessively, as the juicing process can reduce the benefits of the fruit used, and it concentrates the sugar.
“It might take the juice of five or six oranges to fill a cup. That’s a lot of sugary fluid, which can cause an immediate spike in blood sugar levels,” said Beth Czerwony, a dietitian at the Cleveland Clinic.
Excessive sugar in the blood over time can result in insulin resistance, metabolic syndrome, diabetes, heart disease, obesity, and other chronic conditions.
According to the American Academy of Pediatrics, kids aged 1–3 should have no more than 4 ounces (118 mL) of juice daily, 6 ounces (177 mL) for ages 4–6, and 8 ounces (235 mL) for ages 7–18. Older adults are advised to limit it to 8 ounces a day.