A short period of excess food consumption can have long term effects on your body weight and fat storage even after the initial weight is lost. A study published in BioMed Central's open access journal Nutrition & Metabolism has found that a four-week episode of increased energy intake and decreased exercise can cause increased weight and fat mass more than two years later when compared to control individuals.

Åsa Ernersson worked with a team of researchers from Linköping University Sweden to investigate the long term effects of a sedentary and gluttonous lifestyle. They capped the physical activity of 18 individuals and used excessive food consumption to increase their energy intake by an average of 70% for four weeks. A separate control group ate and exercised as normal.

The intervention group gained an average of 6.4 kg in body weight, which was mostly lost 6 months later. However, one year later the intervention group showed an increased fat mass compared to baseline; the differences were even greater after two and a half years. Ernersson said "The long term difference in body weight in the intervention and control groups suggests that there is an extended effect on fat mass after a short period of large food consumption and minimal exercise."

The study provides interesting new evidence to suggest that even a short period of excessive eating and a lack of exercise can potentially change an individual's physiology, causing it to be harder to lose and keep off weight. Ernersson summarised, "The change of fat mass was larger than expected when compared to the controls, it suggests that even short-term behavioural changes may have prolonged effects on health."