Available in red and green varietals, grapes are healthy fruits suitable for followers of a high-carb, low-protein diet. The calories in grapes are approximately the same for red and green varieties, and both are rich in antioxidants that help reduce inflammation and prevent certain types of cancer.
In a small, 100-gram serving of grapes, there are 71 calories. This is equivalent to 21 grapes, each having approximately 3.4 calories per grape.
Nutrition and Calories in Grapes
According to the Mayo Clinic, there are 68 calories in 20 grapes, so a single grape has approximately 3.4 calories. According to USDA FoodData Central, a single serving of both red and green varieties has 161 calories. There are approximately 21 grapes in a 100-gram serving of grapes.
One 100-gram serving of grapes has 0.28 grams of total fat, contributing 0.4 percent of the daily value required by an individual and just 0.88 grams of protein, making it a poor source of protein. Harvard Health explains that protein is essential for muscle development and growth. The average American, however, consumes too much protein on a daily basis — approximately 16 percent of daily calories come from protein.
The red seedless grape carbs in a 100-gram serving are 18 grams. This makes grapes a good alternative for anyone following a high-carb, low-protein diet. A serving of grapes is high in carbohydrates, with the red seedless grapes carbs contributing 6 percent of daily value of carbohydrates.
Considered to be a good source of dietary fiber, one 100-gram serving of grapes supplies 3.5 percent of an individual's daily recommended dose. Having a fiber-rich diet helps prevent constipation and diabetes. And, according to a February 2014 review published in the World Journal of Gastrointestinal Oncology, fiber also helps in increasing satiety and plays an important role in an individual's gut microbiome content.
Read more: Nutrition Information for 8 Oz. of Wine
A 100-gram serving of grapes provides 4 percent of the daily value of potassium, which, according to the U.S. National Library of Medicine, is an essential mineral and electrolyte. Potassium-rich diets help control high blood pressure, and the element is also important in muscle contraction.
Grapes contain large amounts of vitamin K, with a 100-gram serving offering approximately 12 percent of vitamin K's daily value. Vitamin K is important for the body's blood clotting process, and in bone formation. A half cup of grapes contributes 14 percent of daily value of vitamin K to a person's diet.
Benefits of Grapes
Black grapes are rich in caffeic acid, an antioxidant with anti-inflammatory properties. Caffeic acid also has the potential to prevent the formation of cancers, particularly breast and colon cancers, by lowering the reproduction rate of harmful cancer-causing chemicals.
Read more: Can Eating Grapes Help Me Lose Weight?
When it comes to weight loss, black grapes are also high in antioxidants, specifically polyphenols. The authors of a July 2017 review published in Phytotherapy Research found that a diet rich in polyphenols may help reduce body weight. However, larger clinical trials are required to explain the potential mechanism of antioxidants in grapes on weight reduction and management.
Read more: The Best Wines for Resveratrol
In particular, grapes are good sources of flavanones, one of the many types of polyphenols. Flavanones are responsible for the bitter taste in grapes. They may also help protect against the progression of neurodegenerative diseases like Alzheimer's and Parkinson's.
Findings from a January 2017 review published in Molecules indicate that the polyphenol content of grapes also has the potential to reduce oxidative stress, decrease inflammation and prevent the formation of cardiovascular disease. Studies have also found a positive correlation between consuming foods high in polyphenols, and preventing the development of type 2 diabetes.
- USDA FoodData Central: “Green Grapes”
- USDA FoodData Central: “Red Grapes”
- Mayo Clinic: "Snacks: How They Fit Into Your Weight-Loss Plan"
- Harvard Health Publishing: “How Much Protein Do You Need Every Day?"
- MyFoodData.com: "Nutrition Facts for Grapes”
- U.S. National Library of Medicine: “Potassium”
- National Institutes of Health Office of Dietary Supplements: “Vitamin K"
- Phytotherapy Research: “Polyphenols and Their Role in Obesity Management: A Systematic Review of Randomized Clinical Trials”
- Molecules: "Grape Polyphenols' Effects in Human Cardiovascular Diseases and Diabetes”
- World Journal of Gastrointestinal Oncology: "Mechanisms Linking Dietary Fiber, Gut Microbiota and Colon Cancer Prevention”