If you don't reduce your calorie intake, you won't slim down, researcher warns.

(HealthDay)—Eating lots of fruits and vegetables is often recommended as a way to lose weight, but doing so may not help you shed excess pounds, according to researchers.

They reviewed data from more than seven studies that examined how increased fruit and affected .

"Across the board, all studies we reviewed showed a near-zero effect on weight loss," Kathryn Kaiser, an instructor in the School of Public Health at the University of Alabama at Birmingham, said in a university news release.

"So I don't think eating more [fruits and ] alone is necessarily an effective approach for weight loss because just adding them on top of whatever foods a person may be eating is not likely to cause weight change," she added.

"Overly simplified messages don't seem to be very effective," she added.

However, Kaiser and her colleagues also found that eating more fruit does not increase the risk of weight gain.

"It appears that an increase in servings does not increase weight, which is a good thing for getting more vitamins and fiber in one's diet," she said.

The study, which involved 1,200 people in all, was published June 25 in the American Journal of Clinical Nutrition.

Fruits and vegetables provide many health benefits, but people shouldn't expect these foods to help them slim down, Kaiser said.

"In the overall context of a healthy diet, energy reduction is the way to help lose weight, so to reduce weight you have to reduce ," she said.

"People make the assumption that higher-fiber foods like fruits and vegetables will displace the less healthy foods, and that's a mechanism to lose weight; but our findings from the best available evidence show that effect doesn't seem to be present among people simply instructed to increase and vegetable intake," Kaiser concluded.

More information: The U.S. National Institute of Diabetes and Digestive and Kidney Diseases explains how to choose a safe and successful weight-loss program.

Journal information: American Journal of Clinical Nutrition