By Juliette Jowit
For those who find it hard enough to keep within the government's current recommended daily calorie levels, it's bad news: experts are looking to reduce the figure even further.
As food wrappers and health advice everywhere reminds us, guidelines are that women should eat 2,000 calories a day, and men 2,500. Surveys suggest people are eating less than that - but the nation is still getting fatter.
The government's Scientific Advisory Committee for Nutrition has been asked to investigate whether the official levels are wrong because they were based on estimates that people are more active than they actually are.