Is it true that you need to eat more calories in winter to keep warm?
F Salonso, by email

Not unless you’re planning to live outside. It is true that being cold and the action of shivering uses up extra energy as the body tries to keep up normal core temperature. If you were to spend time outside in just a T-shirt this winter your energy requirement could increase by up to 20 per cent, depending how cold it gets and how long you stay outside. But we’re guessing that it wouldn’t be very long. Seriously, with central heating and the fact that most of us wear thick clothes when it’s bitterly cold, very few of us will spend a significant amount of time actually being cold.