Researchers noted a clear correlation between each additional serving of juice per day and a 0.03-point increase in body mass index (BMI).
While the effects vary with age, the BMI increases appear to be greater for children under 11. 100% fruit juices were defined as "fruit juices with no added sugar."
Although the study's conclusions did not establish a direct causal relationship, but rather a correlation, the findings are entirely consistent with clinical observations, according to Dr. Tamara Hannoun, a member of the American Academy of Pediatrics' Committee on Nutrition, who was not involved in the research.
CNN reported on this finding. Experts summarized the effects of juice consumption on blood sugar levels and body mass index (BMI) as follows:
Quantity Consumption:
While research has shown that drinking 100% fruit juice daily is associated with a "slight increase" in weight, Dr. Walter Willett, a professor of epidemiology and nutrition at Harvard University and a co-author of the study, explains that one of the main problems with juice is "quantity consumption," as it becomes very easy to overindulge.
For example, while it might be difficult to eat three oranges at once, we often find ourselves drinking a glass of orange juice (the essence of about three oranges) in a minute or two, and then having another glass. This increases calorie intake and leads to a spike in blood glucose (sugar) levels.
Experts say that, over time, having too much sugar in the blood can lead to insulin resistance, metabolic syndrome, diabetes, heart disease, obesity, and other chronic conditions.
The Difference Between Fruit and Juice:
Dr. Hannoun likens whole fruits and vegetables to "packages packed with nutrients—carbohydrates, protein, fats, minerals, and vitamins—all containing fiber." She emphasizes that biting into and eating them whole is the way our bodies are meant to get their nutritional benefits.
However, when we discard the entire package during juicing, we remove the fiber and structural parts of the food, forcing the body to digest it differently than it was intended to.
Eating a whole apple, for example, doesn't cause a spike in blood sugar levels because fructose, the sugar naturally present in fruit, is released into the bloodstream slowly. Drinking apple juice, on the other hand, floods the blood with fructose, prompting the liver to convert the excess sugar into fat.
Liquid Calories:
Dr. Vasanti Malik, a researcher in the Department of Nutrition at Harvard University and a co-author of the study, explains that when we consume calories in solid form, our brain registers them more effectively and adjusts our food intake accordingly. But if we drink these... Since calories are in liquid form, we may not feel full and start craving more.
Therefore, researchers suggest that "liquid calories" may be a potential mechanism linking 100% of fruit juice consumption to weight gain, as they lead to greater weight gain compared to solid calories.
They add that juice contains little to no fiber compared to whole fruit, resulting in a lower feeling of satiety. This means that juice won't make us feel as full as eating whole fruit.
Juice is not a cure or a substitute for water:
According to the U.S. National Dietary Guidelines, juice should not be considered a healthy way to quench thirst.
Dr. David Katz, a specialist in preventive and lifestyle medicine who was not involved in the study, points out that general guidelines discourage routine juice consumption and warn against relying on it instead of water to quench thirst or for health benefits. Fruit juice is not a recipe for daily health, but it is a better option than soda on occasion.
Should we abstain from drinking Juice Completely?
Researchers explain that the study's findings don't necessarily mean we should completely stop drinking juice, but they do highlight the importance of being mindful and limiting fruit juice consumption by 100% to avoid weight gain and obesity.
Recommended Juice Intake for Children:
The research findings align with the American Academy of Pediatrics (AAP) guidelines for limiting children's juice intake to prevent obesity and tooth decay.
The AAP states that children under 6 years old should consume less than one cup of fruit juice per day. A typical cup is 8 ounces, or about 235 milliliters.
The AAP and the Centers for Disease Control and Prevention (CDC) also advise against giving juice to children under 1 year old.
The guidelines for other age groups are as follows:
- From 1 to 3 years old, the recommended amount of juice is 4 ounces per day (about 120 milliliters).
- From 4 to 6 years old, A maximum of 6 ounces per day (approximately 175 milliliters)
- From 7 to 18 years old, a maximum of 8 ounces per day (approximately 235 milliliters).
Dr. Hannoun emphasizes that there is no health reason to drink juice instead of whole fruits and vegetables, unless the child cannot tolerate eating regular food.
She advises parents not to consider juice a healthy thirst quencher and to offer whole fruit to their children if they can eat it. If juice is unavoidable, it should be limited to half a cup per day.
For those who want to enjoy the taste of fruit but with fewer calories, the Centers for Disease Control and Prevention (CDC) recommend adding a small amount of 100% juice to still or sparkling water for a refreshing, low-calorie beverage.