The Diet Detective: Know Your Calories

Most of us do not know the value of a calorie. In fact, there is a lot of research showing that we often under report the amount of food we eat.

In one study, researchers recruited college undergraduates and showed them nine restaurant entrees. They gave participants serving-size information and brief descriptions of the dishes. The participants were then asked to estimate calories. On average, less healthful items were underestimated by more than 600 calories. But even among those who should have more knowledge about food values, errors of judgment are not uncommon.

Nutritionists, for example, underestimated calorie values by 200 to 600 calories. So how will you do? Test yourself and see if you can figure out how much just one of each item below will cost you in terms of calories.

Nabisco Ritz Snack Cracker or Nabisco Nilla Wafer or Nabisco Triscuit Reduced Fat

Most people are shocked to find out how many calories are in a single cookie or cracker. All these are relatively high. One Ritz Cracker has 16 calories; one Nilla Wafer has 17.5 calories; and the Triscuit Reduced Fat has 17 calories. Just think about how many of these you eat sitting in front of the TV or at your desk—the calories can add up very quickly.

One Almond or One Dried Plum (Prune)

They're both pretty powerful, nutrient-dense foods. Dried plums are packed with important vitamins and minerals, including potassium, vitamin A, magnesium and iron, all of which help you stay healthy, balanced and energized.

Dried plums are also high in disease-fighting anti-aging antioxidants and fiber. However, there are 22 calories in each one. Almonds are seven calories each. No, that's not a misprint—they are each seven calories. So you need to be cautious about eating several handfuls. A small handful (about 1 ounce or 23 nuts and 161 calories) provides an excellent source of vitamin E and magnesium, a good source of protein, riboflavin and fiber, and also offers significant quantities of potassium, calcium, phosphorous, iron and monounsaturated fat.

One Sip of Campbell's Chunky New England Clam Chowder or Campbell's Healthy Request Mexican-Style Chicken Tortilla Soup

Each sip of the New England Clam Chowder is slightly less than 4.4 calories, compared with a sip of Mexican-Style Chicken Tortilla Soup, which is just 2.3 calories. Soup is great if you're looking for something to fill you up. Because soups are water-based, they tend make you feel less hungry without adding too many calories, so you eat less as a result, which is certainly very helpful in terms of losing weight. One study actually found that eating soup at the beginning of your meal could reduce your total mealtime consumption by as much as 100 calories.