Acai: Weight Loss Wonder Fruit?

Can acai berries really help you lose weight? WebMD asked the experts.

Medically Reviewed by Louise Chang, MD on April 16, 2009
4 min read

Acai (pronounced ah-sigh-ee) berries have been making headlines as one of the healthiest foods on the planet. They're supposed to be good for weight loss, anti-aging, and more. But can acai really help you lose weight, as the online ads promise? WebMD asked diet and nutrition experts for the truth about acai and weight loss.

Researchers have found the acai berry has antioxidants that may protect cells from damage caused by harmful molecules in the body called "free radicals," and may possibly help against diseases such as heart disease and cancer. But when it comes to weight loss, the hype is ahead of the science, because the research evidence for such a connection is lacking. Even Oprah Winfrey has posted comments on her web site disassociating herself with acai products that claim to promote weight loss.

"Acai is a nutrient-rich source of antioxidants, much like many other fruits, but there is nothing magical about the fruit to cause weight loss," says David Grotto, RD, author of 101 Foods That Could Save Your Life.

"There is not any single food, including the super-healthy acai berry, that can provide the solution to weight loss. To lose weight, you need to control calories with a healthy lifestyle approach that includes plenty of physical activity, nutritious foods, and adequate rest."

No single "acai berry diet" exists. Instead, you'll find advertisements for products such as "acai berry detox," "acai burn," "acai pure" and "acai berry edge," promising quick weight loss. Some of the ads promise "450% more weight loss than dieting and exercise alone" and claim you can lose up to 20 pounds in one week.

According to some web sites selling acai products, acai's fiber and essential fatty acid content contribute to its ability to "burn fat more efficiently, process food more quickly, cut down on cravings, and boost metabolism." Detox acai products further promise to "cleanse" your system of fat and rid your body of "toxic buildup that is weighing you down."

How can they make these claims? Unlike drugs, over-the-counter supplements and foods are not closely regulated, so some manufacturers can over-sell health benefits of their products.

Grotto does note that there is something unique about acai: It's one of the few fruits, besides avocados, that contain monounsaturated fats (MUFAS).

While MUFAS may work to help keep you feeling satisfied if you include them in a calorie-controlled diet, the amount in acai is so small that you would need to consume large quantities to get enough MUFAs, he says. And not only would that be expensive, he says, it would add lots of extra calories. (MUFAS are also found in olives, avocados, nuts, seeds, dark chocolate, soybean, flax, and olive and sunflower oils.)

Not only has acai not been proven to have the weight loss powers claimed in some of the ads, consumer groups warn that people who sign up for a "free" trial of acai diet products can get burned.

The Center for Science in the Public Interest, a food and nutrition watchdog group, recently issued a warning that many companies offering free trials of acai diet products actually end up charging customers. Customers are asked to supply credit card information for shipping of the "free" sample, and some have immediately been hit with monthly charges of $80-$90.

The Better Business Bureau of Northern Indiana offered a similar warning against online ads for acai weight loss products.

Grown in the Amazon River basin in Brazil, acai is a deep purple berry that tastes like a combination of wild berries and chocolate.

The berry's anthocyanin content gives it its rich purple color. Anthocyanins are powerful antioxidants that may protect the body against cancer, inflammation, diabetes, aging, neurological diseases, and bacterial infections.

A 4-ounce serving of pure acai contains about 100 calories, iron, calcium, fiber, vitamin A, and 6 grams of fat -- but because the berries do not transport well, most food products sold commercially use only a small amount of pure acai. Acai is available in capsules, powdered, as frozen pulp, and in bottled smoothies and other drinks.

If you're considering buying acai products, read the labels, because the drinks may contain lots of added sugars and calories. And, be prepared for sticker shock at the grocery store, as most acai products carry a hefty price.

"Products made from acai are expensive because 95% of the berry is seed, and only 5% is the skin used to make food and beverages," says Grotto.

Keep in mind that you can get similarly antioxidant-rich whole fruits and vegetables for a fraction of the cost of acai, and in their natural form (without extra sugar or calories). Blueberries, blackberries, and raspberries are more economical choices that deliver similar health benefits, says Grotto.

The bottom line, experts say, is that acai can be part of a weight loss plan that includes a calorie-controlled diet, but by itself, it's just another fruit. If you really want to lose weight, experts say, choose an eating plan that you can stick with long-term, and be sure to get regular exercise.

If you're looking for a healthy diet with antioxidant benefits, Michael Roizen, MD, chief wellness officer for the Cleveland Clinic, suggests the so-called DASH (Dietary Approaches to Stop Hypertension) diet.

"The DASH diet contains an abundance of richly colored, antioxidant-rich fruits and vegetables along with low-fat dairy, whole grains, nuts, beans, fish, and lean meat that has been proven to promote weight loss and lower blood pressure," Roizen says.