Fast food diet puts you on a diet for years
A diet of burgers and fries can leave a mark for years afterwards. Over-eating for just four weeks can increase fat mass and weight over two years later. People who took part in a fast-food study at Linköping University were two and a half years later still fatter than before the study, show the results now published in the journal Nutrition & Metabolism.
The study, which received extensive publicity, included 18 healthy and of normal weight young men and women. During four weeks they were on a high energy diet - 70 per cent higher than normally- and reduced their physical activity to a maximum of 5,000 steps per day. This resulted in an average weight increase of 6.4 kg, with body fat levels up by a third.
After the four week diet ended follow-ups were made after six, twelve and 30 months. The participants' weight and body fat decreased gradually, but at a 30-month weight control it was found that their weight had begun to increase again, the average weight was now 3.1 kg more than before the study. The corresponding weight gain of a control group was 0.1 kg.
The reasons for the increase in body fat are not clear, but everything suggests that the subjects returned to the diet and the lifestyle they had before the experiment, says Åsa Ernersson, lead author and doctoral student in nursing studies at LiU.
“I interviewed the participants and they were all tired of fast food”, says Åsa Ernersson who conducted the study with Professor Fredrik Nyström and Senior Lecturer Torbjörn Lindström.
Article: Long-term increase of fat mass after a four week intervention with a fast food-based hyper-alimentation and limitation of physical activity by Åsa Ernersson, Fredrik H. Nyström and Torbjörn Lindström. Nutrition & Metabolism, Open Access 25 August 2010.
Contact: Åsa Ernersson, 010-1038183, 0708-759786, asa.ernersson @ liu.se
Last updated: 2010-09-27