LITTLE ROCK, Ark. (KTHV) - Many fad diets come and go but some seem to stick around through the decades. One of those diets is the grapefruit diet.

It has been around since the 1930’s and claimed grapefruits are a type of super food that burn fat and make you lose weight fast. But is there any truth to it?

THV11 spoke with David Rath, a nutritionist for over 20 years. He has seen the grapefruit diet grow and fall in popularity.

Amanda Jaeger & David Rath, Credit: KTHV

“The premise behind it is that grapefruit has a substance in it that causes you to lose weight,” he said.

People claim grapefruit is so filling, you can only eat so many per day, which means consuming a lot fewer calories. Other variations of the diet call for people to eat at least half a grapefruit or 4 ounces of 100 percent grapefruit juice before each meal to make them less hungry and lose fat. Others claim grapefruits have super enzymes to burn fat.

Rath said most of those claims aren’t true, but grapefruits do have great qualities for people to consider. They’re high in Vitamin C, an antioxidant that helps reduce the risk for disease. They’re low in calories. If you eat the whole fruit, including the pulp, it can help lower your cholesterol.

The catch is those amazing qualities aren’t only evident in grapefruits. Most fruits and vegetables have some of those qualities.

Credit: KTHV

“Fruits and vegetables are about 90 percent water and have a lot of fiber that fills you up without getting you many calories,” said Rath.

He added people should absolutely include grapefruits into their diet, as well as other fruits and vegetables and foods from the five major food groups. He said the age-old truth “make sure to eat those fruits and veggies” really does win. It is the key to making you feel fuller while consuming fewer calories and giving you great nutrients.

But there are dangers with the grapefruit diet models that tout eating grapefruits on overload while skimping out on other healthy foods. It’s also dangerous to use any of the grapefruit diet models that recommend eating a low number of calories each day.

“It can actually be harmful to your weight loss goals and cause you to go into starvation mode from consuming too few calories,” said Rath. “Very low-calorie diets make the body think it is starving, which lowers your metabolism, and makes it hard for you to lose weight.”

Too many grapefruits and too few calories will also not provide you the nutrition your body needs. Even if your weight drops temporarily, it’s not going to last and it could cause more damage than you would think.

“That type of diet is not sustainable because people aren't going to eat like that for the rest of their life,” he said.

Credit: KTHV

Rath added the best way to stay healthy is to make good meal choices from the five food groups while staying within your recommended calorie level. It’s important to incorporate physical activity because that's another way to burn calories and maintain good fitness levels.

It's also important to check with your doctor and nutritionist before trying any new diets because they can interact with medication.

Grapefruits, for example, can interact with certain medications and cause serious health issues.

For more information on healthy eating and living just click here. For more information from David Rath, you can visit his website here.