I had an a-ha moment last year as I walked around the concourse of my office building. I realized that the bulk of the food sold in restaurants, fast food shops and grocery stores is junk food. More importantly, I stopped thinking of prepared meals, fast food or restaurant food as a valid eating option. Some sort of switch flipped; I lost interest in buying food and preferred to eat food prepared at home.
I realized that it is too easy to overeat food that is prepared by food manufacturers and restaurants.
(In general, I'm referring to manufactured meals - meals made by someone else and/or somewhere else. Of course this includes snack foods and "healthy" fast food places that serve enormous salads.)
If you think about it, food manufacturers have teams dedicated to creating convenient meals that are so tasty that you will like it enough to buy again and again. They test, use focus groups as guidance to perfect a product that will appeal to the the most consumers. This team also works to overcome obstacles such as an ingredient list constrained by a budget and projected pricing and a manufacturing date that is weeks/months prior to the consumption date.
Plus, let's not forget that the food business is a competitive market. Luckily, the food marketers work on a plan to develop product awareness so you will remember to buy their frozen lazagna at the grocery store and again the following week. If the product happens to be low-fat and doesn't taste all that great - the food marketers will market the health benefits and let the health halo do the rest.
In the case of fast food and restaurants, it's a bit of a double whammy - there is the taste thing and the huge serving size thing. Servings are massive, even the children's meals are too big and in the wrong proportions for healthy eating (ie. vegetables rarely take up half the plate). I'm even wary of the healthy fast food places that sell big salads heaping with various prepared toppings with mayonnaise and cheese.
Of course, some prepared meals are healthier choices than others. On the rare occasion that I buy my lunch (once every couple of months), my first choice is a place where I can get a gourmet salad and a sandwich.
And while I realize that it is one of the healthier choices, the sandwich is big, and I'm certain the salad dressing in full fat.
In my eyes, food made in factories, fast food/restaurants meals are treated like chocolate bars and should only be eaten occasionally.
If you are interested in controlling your eating, control what you eat by making the food you eat.
Eat food and be wary of eating products.