The idea here is to be  realistic with your self. If you do eat out frequently (yes once a week  is frequent enough), don’t lie to your self by saying, ‘it’s ok, just  this once, this doesn’t happen everyday’. No it does not happen  everyday, but remember that even once a week over time adds to those  stubborn pounds.
If you eat out infrequently then by all means indulge your self every once in a while and feel free to ignore the tips below.
Here are some tips on what to order (or what not to order) when you’re going out to eat.
1) Say no to the drink
If  the agenda is to step out for a good meal, then say no to the  afterthought drink. When the waiter asks you if you would like something  to drink, firmly shake your head and say no. Those mocktails, soft  drinks, and fruit punch glasses add a huge number of empty calories to  your meal in a very subtle way. Before you know it, you will have  consumed enough of calories to overtake your entire home cooked meal and  then some. Whatever you eat after that is just extra. Keep this in mind  the next time a pink creamy drink with an umbrella entices you with her  feminine wiles.
2) Eat the appetizers
The appetizers, unless they're fried, are healthier (the paneer, mushroom, or chicken kebabs) than the main meal of creamy gravies and butter soaked naans.  Make sure, you eat the appetizers well. There are always healthy  choices on every menu for people who are watching what they eat. Try and  order some mixed veggies, some greens, and some white meat for starters  so that you are 80% full by the time the main course comes around.   Needless to say that if you order fried cheese balls for appetizers, the  above does not hold true and you only have yourself to blame.
3) Eat the salads
Nowadays,  because presentation is king, most meals come with pretty side salads.  Help your self to the salads on the table even if everyone else is  pretending that they have not seen it and are trying their level best to  ignore its existence. This will help satiate your appetite and you will  not end up over eating on other far less healthy food.
4) Don’t over eat
If  you’ve come to dinner after a long day, hungry, then chances are you  will over-eat by eating quickly. Instead try a soup first or grab a  handful of nuts before getting to dinner. This will ensure that you can  eat slowly without swallowing your food and your stomach will tell you  when to stop. Make sure you listen to your body and stop when it tells  you to.
5) Avoid the Dessert
Ok  I’ve hit on a 
nerve here. This is, by far, the hardest of them all,  isn't it? Well, 
how about sharing. A couple of bites will not harm you  too much, but an
 entire dessert? After eating a sumptuous and satisfying  meal, do you 
really need to eat another meal? How many times have you  gone home 
holding your stomach, groaning and vowing that you will not  over 
indulge the next time? Well now’s the time to make amends. You can  
substitute dessert by carrying a bar of dark chocolate or some  
chocolate-coated nuts with you. You can satisfy the sweet craving  
without going all out. Maybe ask for a cup of coffee instead. It leaves a
  great after taste and while everyone else is chomping down the dessert
  you can busy yourself with exploring the exotic flavours of rich 
coffee.
So here they are: 5 practical ways to avoid feeling  guilty when you eat out. You will be surprised to see how easy they are  to implement when you decide to give these 5 tips for eating out a  shot.