9 Bad Habits That Science Says Are Good For You

7. Cheating On Your Diet

Try as hard as you like to be healthy - living on lemon water, lettuce and avocado toast, or whatever it is the beautiful people eat - there will always come a day when all you can think about is a great big pizza, dripping in melted cheese. Giving in to temptation will make you guilty, resisting will make you miserable, so what to do?

Good news, the odd cheat meal is actually a pretty solid healthy-eating tactic. A lot of nutrition experts will agree that the 90/10 rule - that is, 90% of your diet should be "good" and 10% "bad" - can help you stay on the straight and narrow without wanting to stab celery sticks in your eyes and without sliding back into bad habits.

As well as giving you a psychological boost, the occasional dietary splurge could actually help keep your metabolism on its toes, by shaking up your leptin levels (that's the hormone that controls appetite and energy levels) and preventing your body from completely adjusting to a life of salad.