A study from the University of California, Berkeley, found that drinking grapefruit juice when eating food high in fat could lower the amount of weight gain by almost a fifth.
The Grapefruit Diet, where those trying to lose weight drink a glass of juice with every meal, has been around since the 1930s but became particularly popular in the 1970s. Scientists tested the effects of the fruit on mice to see if it can really help boost metabolism.
The study authors randomly divided mice into six groups and gave each the same amount of and exercise. One of the groups was given grapefruit juice with every meal while another group only drank water.
When the mice were fed fatty food for three months, those given grapefruit juice to drink gained up to 18% less weight than those given water.
The findings, published in the journal Plos One, also suggest that grapefruit could be used to stabilise blood sugar levels and help patients to manage diabetes, as the mice who drank water had higher blood sugar and insulin levels.
The researchers acknowledge that more research is needed to confirm exactly how grapefruit stops weight gain.
According to the MailOnline, Mariette Abrahams, a spokesperson from The British Dietetic Association, said The Grapefruit Diet is not an advised way to lose weight.
"Grapefruit should be part of a healthy balanced diet, but it shouldn’t be the focus of the diet," she said.
If you want to add grapefruit to your diet in a healthy way, check out the recipes below.