Eat Soup & Salad First.

If you want to lose weight or eat less in general, try eating a water or broth-based soup or a fiber-filled salad before your main dish, especially when eating out. You’ll naturally eat less of the main dish, which is usually filled with the most calories and have high fat content.
Make sure you avoid creamy soups like chowder and other kinds of heavy soups, that uses butter and cream. Choose more water based soups.

Also, order a salad with dressing on the side so you can control how much to put on it. The fat and calories are usually in the salad dressing rather than the actual salad. Opt for a simple balsamic vinaigrette.
Also, avoid eating bread before you eat your soup or salad. You can ask for a hot beverage like tea with lemon and sip that while waiting for your salad or soup. Hot beverages will give you a sensation of fullness, which can lead to eating less.

Also, put your fork, chopsticks, and spoon down when you’re about 80 percent full and have the first sensation of being full. It takes some practice, but it can be a good habit to develop. Whatever you eat, don’t stress out. Exercise moderation and balance and enjoy the food and the company.