Does a cheat meal every 7 days ruin your diet ? For example pizza

Hi Clive It depends on what your current health/fitness goals are.

If your goal is to live a healthy lifestyle while maintaining lean muscle or performing well in your sport then yes, if you follow a healthy diet during the rest of the week, a cheat meal (or treat meal as we prefer to call it) can definitely find its place once a week. This will have both psychological and physiological benefits. It will keep one motivated to eat healthy during the week, that way
“earning” a pass for a treat meal so to speak, and it can also spike your metabolism. However in saying so one needs to exercise a certain amount of discipline in making sure the cheating/treating does not go beyond that particular meal.

If on the other hand one’s goal is to shred down for a physique competition or photoshoot one needs to be careful on how often to take a treat meal, in line with the overall plan.