Although a glass of orange juice may count as a serving of fruit and is more nutritious than soda, it isn't necessarily your best choice if you're trying to lose weight. OJ is relatively high in calories per serving, and it won't keep you full as long as solid food will. You'd be better off eating a fresh orange and drinking a glass of water or other no-calorie beverage. But this doesn't mean you can't include it in a weight-loss diet on occasion.
Calorie and Micronutrient Content
A 1-cup serving of orange juice has about 122 calories, almost all of which come from the 28.7 grams of carbohydrates it contains. A medium orange has only 62 calories, so you could eat two of them for about the same number of calories in one glass of orange juice. The cup of orange juice contains a little more vitamin C, folate and potassium than a single orange, but per-calorie, the orange provides more micronutrients.
Fruits are typically recommended for people trying to lose weight because most are low in energy density, or calories per gram. Low-energy-density foods help fill you up with fewer calories, making it easier to stay within your daily calorie limit without feeling hungry. Orange juice and oranges both have an energy density of 0.5 calories per gram, which is considered very low. A 1-cup serving of orange juice weighs about 249 grams, while an orange weighs about 131 grams, which accounts for the higher calories in a serving of orange juice. A smaller serving will allow you to drink orange juice without getting more calories than you would from an orange.
People who eat more fiber tend to weigh less, and diets higher in fiber may help with weight loss by increasing feelings of fullness and slightly decreasing the absorption of calories from the food you eat, according to an article published in "Nutrition" in March 2005. Orange juice has very little fiber, especially if you prefer the pulp-free version. A glass has only 0.7 gram of fiber, compared with 3.1 grams, or 12 percent of the daily value, in a medium orange.
Considerations and Serving Tips
You'll need to replace another higher-calorie food with orange juice if you're using it as part of a weight-loss diet, because you need to create a 3,500-calorie energy deficit to lose just one pound. Exercising more can also help you create this energy deficit. If you like the flavor of orange juice but want to cut the calories a bit, dilute it with either sparkling or plain water.