You've eaten well all week - plenty of greens, lean meats and bucket loads of water and are feeling lean and healthy then the weekend weekend rears it's ugly head to undo all the good with its social events filler with wicked temptation and late nights.
When it comes to weight loss it's best to view your total calorie intake throughout the week as opposed to each day (as shown in this stolen infographic) for it's so easy to have 5 little daily wins and then get too excited over the weekend to tip your intake over the edge.
Also, this way also allows you to manage days around expected heavier ones. Think of it like your bank balance, you need to save some money before a big purchase else you'll be hiding behind the sofa from the dept collectors before you know it. For this purpose let's think of those dept collectors as that unwanted weight - both annoying little shits.
Of course, we are all going to have days where we eat and drink too much, it's just about managing the days around that event to minimise the damage.