This appears to be more of a cultural issue than a scientific one. Many European countries customarily eat the salad after the main meal, while Americans tend to eat it before. I suppose the case could be made that eating a salad prior to the main course may allow one to fill up sooner and eat less in the following courses/meal. This would be fine if the salad was full of fresh vegetables and not loaded with calorie and fat laden add-ons and dressing. Sadly, many pre-meal salads are slathered in rich, creamy dressings, cheese, bacon bits and other caloric add-ons. In this instance, they simply contribute additional fat and calories to your meal. Ultimately, it makes no difference when the salad is eaten. The processes of digestion and absorption take many hours and the food eaten is mixed and churned together as it makes its way through your body.