I know, this is a long post, but it's good info!!

When talking to people who are trying to lose weight, I often come across the "dieter's paradox": They "hardly eat anything," but they still don't lose weight. This seems to be one of our biggest problems -- we never believe we're eating anything.

It's been reported in the New England Journal of Medicine that people attempting to lose weight tend to underestimate the amount they eat by as much as 47 percent and to overestimate their physical activity by as much as 51 percent. When scientists at the USDA's Beltsville Human Nutrition Research Center in Maryland asked 98 men and women to state how much they ate in a 24-hour period, they found that 6 out of 7 women underreported by an average of 621 calories, and 6 out of 10 men underreported by an average of 581 calories. When the American Cancer Institute did a study asking Americans to determine the portion sizes of eight specific foods, only 1 percent got them all right. Sixty-one percent couldn't get more than four correct.

What should you do? Challenge yourself to find out what you're actually consuming. Keep track of everything you eat, even the small, insignificant foods, (e.g., a piece of gum or one grape) for at least three or four days. Why do those little things matter? According to some researchers, we consume on average about 1,000,000 calories per year, and just 25 extra calories per day means an additional 2.5 pounds per year. Multiply that by 10 years, and you've just put on 25 pounds -- that's how it happens.
Following are the calorie counts for "just one" of a few different food items. And remember that you would have to walk for one minute to burn off every four calories you eat in excess of your daily calorie budget (an average of 2,000 calories). Also, keep in mind that the point of presenting the calorie "costs" of these foods isn't to get you to stop eating them, but rather to get you to think about your food before you eat it.

One Pringles Potato Chip vs. One McDonald's French Fry
Believe it or not, one french fry has only five calories, while a single Pringles chip is double at 10 calories.
One Grape Tomato vs. One Green Seedless Grape
The winner: The grape tomato has only one calorie, whereas a green grape has four. However, both are great choices, particularly for their antioxidant content (e.g., grapes have flavonoids and tomatoes have lycopene).
One Strand of Whole Wheat Spaghetti vs. One Tablespoon of Campbell's Select Herbed Chicken with Roasted Vegetables Soup
The strand of spaghetti has only 3.5 calories, whereas the sip of soup has 6.25 calories. Keep in mind, however, research indicates that eating a low-calorie soup is a great way to fill up before a meal.

One Stick of Wrigley's Juicy Fruit Gum vs. One Piece of Bazooka
I have mixed feelings about gum: Some people say it helps them control their weight, but I don't love the way it looks. That said, who would think that chewing two or three pieces of gum a day adds up to 4.5 pounds per year? The winner here is Juicy Fruit at 10 calories, compared with Bazooka's 15.

One M&M vs. One Jelly Belly vs. One Peppermint Altoid
M&M's can be a pretty good deal at times, especially if you're comparing them to a regular candy bar (one bite of a Hershey's bar with almonds has 37 calories) which always seems to disappear so fast. Also, if you're sharing M&M's, they split up nicely because you can pass the bag back and forth. However, they have 4.3 calories per piece, which add up fast as you're popping them into your mouth. As far as jelly beans go, well, I hear a lot about them being low in fat, but that doesn't mean very much -- they're still four calories per bean. If you're satisfied with a few, that's great, but watch out for unconscious candy dish consumption. Altoids and other mints are another story. They supposedly serve a function -- to freshen your breath -- so the calories don't matter, right? Sorry, but all calories count, and please spare me the argument that it takes work to suck on the mint. One Altoid has almost 3.5 calories.

One Bite-Size Cube of Cheddar Cheese vs. One Famous Amos Chocolate Chip Cookie
Clearly the cheese is the better choice nutritionally, but you need to know that cheese is not a health food you can consume without guilt -- one bite-size (1/2-inch) cube has 55 calories, whereas the cookie has only 37.5 calories. Whenever possible, go with low-fat cheese. A great one is Cabot's Vermont 50% Light Cheddar -- 35 calories per bite-size (1/2-inch) cube.

One Fritos Original Corn Chip vs. One Cashew nut
Here again, the cashew has health benefits that far outweigh those of the nutritionally bland corn chip; however, cashews have 8.5 calories per nut, whereas Fritos contain five per chip. So just because you hear that nuts are healthful doesn't give you carte blanche to overindulge -- you're supposed to eat nuts in place of something else in your diet that's high in calories and nutritionally inferior, not simply add them.

One Broccoli Floret vs. One Baby Carrot
Both are super vegetables. Basically, you can't eat enough of either one. Carrots have the antioxidant beta carotene, which may reduce the risk of heart disease and cancer and promote better vision, especially night vision, while broccoli is just loaded with health benefits (high in vitamins A, C, and K and a great source of iron and folate). Okay, so which is lower in calories? It's the broccoli at 0.8 calories; the baby carrot has 1.25.

Create Your Own Food Diary
If you would like to keep a food diary for a few days (I recommend at least three), follow these few simple steps.

Meal, Time, and Place
Record the approximate time you sit down to eat. This may help you find the eating schedule that works best for you. Also, record what meal it is (e.g., breakfast, midmorning snack, etc.) and where you ate it -- whether it is on the run, sitting at your desk, at a restaurant, etc.

Hunger Level
Record your level of hunger on a scale of one to five, one being the least hungry and five being the most hungry. You should aim to be between three and four when you're eating.

Dining Companions
Write down with whom you eat and what you talk about. This information could offer clues to unconscious eating or stress eating.

Feelings and Mood
Record how you feel before, during, and/or after you eat. Before is probably the most important because it can have the greatest effect on how much and what you eat. Try to keep track of whether you have general feelings like being happy or sad, or specific ones like "stressed at work," "angry at spouse," or "having a great day."

Food and Drink
Record all the individual foods you eat and the beverages you drink, including accurate portion sizes. Anything that goes into your mouth should be in your food diary -- including nibbles from the refrigerator and bites from other people's plates!

Nutrient Information
Record the calories, fat, and carbs for each food/meal you eat. Total your calories at the end of the day to make sure you are staying within your allotted calorie budget. To figure out the calories, carbs, and fat in many of the foods you eat, go to www.dietdetective.com/calories/, which lists more than 7,500 foods.

Charles Stuart Platkin is a nutrition and public health advocate, author of The Diet Detective's Calorie Bargain Bible (Simon & Schuster, 2007), and founder of DietDetective.com, the health and fitness network. Copyright 2007 by Charles Stuart Platkin.