"If you really want to hold on to the changes you promised yourself on holiday, I suggest you remember your Ps and Qs: Remind: choose a key word to encourage you, and stick Post-It notes on your mirrors and wardrobes.

"Persist: it takes three weeks to break an old habit, and at least three more to establish a new one. Don't expect real change for at least six weeks.

"Quantify: find a way to measure your change, so you can be aware of progress. For example, don't plan just to lose weight: resolve to lose five kilos."

Linda Blair, clinical psychologist