If you are trying to lose weight, choose food based on their weight-to-calorie ratio. You want to eat food that weighs a lot but has few calories and avoid food that is light in weight but hefty in calories.

Fruits and vegetables are the big winners in the heavy weight-low calorie department, according to Tufts University. They weigh a lot because of their fiber and water content and yet do not have many calories. For example, one cup of cantaloupe or 'melon' weighs 5.5 ounces but only has 56 calories. A cup of cooked spinach weighs six ounces but only has 42 calories.

Now, compare that to six cups of buttered popcorn that only weighs three ounces and contains 420 calories or, even worse, one ounce of potato chips that has 152 calories (if you ate four ounces, you would be inviting 608 calories to feel at home in your fat cells). That's what I call "small but terrible".

Most snack food doesn't weigh much but sure have a lot of calories. This means you can eat a lot of them without feeling full and without realizing it take in many excess calories that you don't need.

Most cookies weigh ½ ounce and contain 50 calories. Eat six cookies and you only have three ounces of weight but you've racked up 300 calories. 1.5 ounces of a chocolate bar contain 220 calories. A small croissant only weighs two ounces but has 230 calories. According to the New Zealand University study, food that is light in weight but high in calories is probably the worst kind of food to eat if you are trying to lose weight. It's sort of like 'double jeopardy' - you are still hungry but you have already eaten many calories.