The study

For 12 weeks, a group of just over 260 patients swapped their normal food for a very-low-energy diet in the form of soups and milkshakes. Of this, 169 patients lost a lot of weight, averaging 16% of their body weight.

They were then divided into two groups so that they could switch back at different rates from the very-low-energy diet to energy reduced portions of normal food. One group completed the refeeding in a week, while the other took 6 weeks.

"After 10 months the patients with the 6-week refeeding period had gained 4% in weight from their minimum weight while patients with the 1-week refeeding period gained 8%," researcher Lena Gripeteg, Sahlgrenska Academy, University of Gothenburg, is reported to have said.

Watch what you eat

Very-low-energy diets have been used for many years in the health service to achieve rapid and safe weight loss in obese patients. While this treatment method is well-studied, there is a risk that patients will gain weight when they start to eat normal food again.

"We therefore want to look at the importance of different treatment advice on the transition from the very-low-energy diet back to normal food, and assess what actually works," said Gripeteg.

"A simple tip that seems to work for patients is to revert slowly to normal food after losing weight on a very-low-energy diet," added Gripeteg.

Pic: Michal Zacharzewski