Researchers at Pennsylvania State University are providing some clues to help you achieve permanent weight loss. They are looking at the effects of your food choices and how they affect your ability to lose weight. (The influence of food portion size and energy density on energy intake: implications for weight management. Am J Clin Nutr. 2005 Jul;82(1 Suppl):236S-241S.)

But what they found was somewhat surprising. They found that people tend to eat a meal based on how big it is.

The problem of meal size and weight loss is that some foods are much denser than others. For example, fatty meats and rich sauces are much denser than fresh fruits and vegetables.

As hard as it may be to believe, if you eat an extra 100 calories per day you will gain nine pounds per year. And it takes very little of this calorically dense food to amount to 100 calories.

Now, it is true that portions of foods in our modern society have become bloated beyond all reason. A generation ago eight ounces of soda was considered a full serving; now you see people drinking 64 ounce cups.

If you are living in this society and are overweight you are suffering from these oversized portions to some degree.

If you are used to eating a whole plate of food, you will want to eat a whole plate whether the food is light or heavy. If you are used to eating two bowls of food, you will want to eat two bowls full whether the food is low calorie or high calorie.

Your body only needs about 600-700 calories for each meal; this is a normal meal size in a lean, healthy adult.

But a meal with less dense foods, like grains, soups and vegetables, will be a lot of food. There are not too many calories in a bowl of soup and a heap of lettuce, and add some grains and you will have plenty of food. Even with some lean meat you will still get more to eat.

So when you add in the less calorically dense foods, which are mainly foods like fruits, vegetables, grains and rice, you get a lot more to eat, plain and simple. And it is always easier to stick with your weight loss efforts if you feel you are getting enough to eat.