Plan
Plan
Plan!
Know what you're having even if you overplan it's better to not eat something on plan than to throw your hands up and have a Big Mac!!
So if you're taking lunch to work, take more than you need, normally only eat one apple? Take two!
Having a salad with ham eggs and salad? Keep your eggs in the shells , and the ham in a pack, but take double! If you only eat one egg and two slices of ham then you have something for another day!
I cook and eat at work sometimes I have to bring in breakfast, lunch and dinner for that day and breakfast and lunch for the next, I take in enough for three lunches and breakfasts and more fruit/ veg than I need, that way I'm not tempted to buy a pastie or whatever!
If I need a snack in the evening I'll have it!