A little while back, I wrote an article called 14 Ways to Get Fatter. One of the 14 fat-gaining habits I wrote about was to “Start Each Day with a Bowl of Cereal and Fruit Juice.” Though this is a common American breakfast today, it’s not a great way to start the day. Not only is such a breakfast low in protein and good fat, it’s also very high in carbohydrates, much of which are highly processed. We’ll save the cereal as the topic for a different day. The most popular fruit juice is still orange juice, with more than 25% of the population drinking it at least three times per week.[i] A new study looked at the effects of drinking orange juice with breakfast. Investigators compared a standard breakfast with orange juice or water as the beverage, and analyzed the effects they had on lipid profiles and fat utilization.[ii]
Any fruit juice contains a high concentration of sugar. Even though the juice may be squeezed from fruit, the effects the concentrated juice has on the body are quite different from what happens when consuming a piece of whole fruit. The processing that store-bought juice goes through is much more than simply squeezing the juice out of fruit. According to the US Dietary Guidelines, fruit juice is acceptable as a “serving” of fruit, leaving many people feeling they’ll get similar benefits from drinking juice as they would from whole fruit. And since so many people look for convenience, it’s easy to understand why they pick fruit juice over whole fruit.
Fruit juice contains both fructose and glucose. Fructose does not have much of an impact on raising blood sugar because of the way it is metabolized by the liver, but it may lead to a variety of health concerns, including elevated triglyceride levels and development of non-alcoholic fatty liver disease. Glucose raises blood sugar levels, which increases insulin secretion and over time, can help contribute to insulin resistance. Though some people may think drinking fruit juice in moderation is okay, the study shows that drinking it has an immediate effect on one’s metabolism, which should make you think twice about adding it to your nutrition plan.
Participants in the study were fed a breakfast quite different from the breakfast we’d recommend for people. It included one serving of cereal with 2% milk and one serving of cream cheese on one-half of a toasted plain bagel. This was a crossover study, meaning the same group was fed on two different occasions. On one occasion, they were fed the breakfast mentioned, along with tap water to drink. On the other occasion, the water was replaced with two cups (500 mL) of orange juice. The breakfast food itself was bad enough without the OJ, supplying 55 grams of carbohydrate, but when the orange juice was added, the breakfast meal totaled a whopping 106 grams of carbohydrates. Though that sounds like a lot, it’s common for millions of Americans.
The breakfast that included orange juice contained an additional 51 grams of carbohydrates. The feeling of hunger following both meals was the same. This means that even though the breakfast with orange juice contained more calories and a lot more carbohydrates, these extra calories did not signal the body to eat less following the meal. Sugary foods often do little to curb appetite, so people may eat a lot more without feeling like they’ve done so.
Another interesting effect was that HDL cholesterol (protective cholesterol) was lower after the breakfast that included the orange juice. Also, for the adults in the study, plasma free fatty acids (fatty acids used for fuel) were reduced, and triglycerides and VLDL (small, dense) cholesterol were much higher after the breakfast with orange juice. Fat utilization after the breakfast with orange juice was reduced by about 30%! So following the breakfast with the orange juice, study participants saw a reduction in fat burning (or increased reliance on sugar for energy), lowered HDL cholesterol, and increased triglycerides and VLDL cholesterol.
There were a couple of flaws in the study. The study did not maintain the same calorie levels between the two breakfasts. Orange juice added a couple hundred more calories to the breakfast meal, so we can’t say the change in lipids and fat utilization was because of the orange juice itself, or simply because of the increased carbohydrates consumed. It would have been interesting to see what would have happened if a third breakfast had been served. In the third breakfast option, participants could have been fed a larger amount of cereal or the other half of the bagel, which would have also increased the carbohydrate content. In all likelihood, the issue is the higher amount of carbohydrate, and it probably wouldn’t have mattered if it came from the orange juice, or extra cereal or more of the bagel.
Also, it would have been wise to compare the baseline breakfast in this study against a healthier, lower-carb and higher-protein breakfast. More than likely, the fat utilization and lipid parameters would have been further improved by avoiding the bagel and cereal all together, and replacing them with an omelet and water, tea or coffee.
If you have the habit of drinking fruit juice with breakfast, consider making a change. Though there are some vitamins in a typical glass of juice, the amount of sugar in it isn’t that much different than drinking soda. I haven’t had a chance to read it yet, but I have Squeezed: What You Don’t Know About Orange Juice on my list of books to read. The highly recommended book details the history of orange juice manufacturing and leads the reader through the process of producing it. Like many of the foods in our diet, orange juice goes through more processing than most people realize. A piece of whole fruit would be much healthier. A lower-carb, higher-protein breakfast would be even better. If you want to be a fat-burning machine, skip the juice. Drink water, coffee, tea and some full-fat milk (if you tolerate it) instead.
[ii] Stookey JD, Hamer J, Espinoza G, et al. Orange Juice Limits Postprandial Fat Oxidation after Breakfast in Normal-Weight Adolescents and Adults. Adv.Nutr. 3: 629S-635S. 2012
This article is not intended for the treatment or prevention of disease, nor as a substitute for medical treatment, nor as an alternative to medical advice. Use of recommendations in this and other articles is at the choice and risk of the reader.