Hi, the theory is that some foods burn more calories to chew and digest than they contain. Sadly there are no such things as "negative calorie" foods, according to my research, but people insist on believing there are! Celery is very low in calories though and like most vegetables that are eaten without something else on them (dips and such), they are very healthy and add very few calories to your daily total.
If you truly want to lose fat, my best suggestion is to learn to eat healthy.
That means understand the food pyramid, the food groups, the recommended servings, etc. That is how you should eat for life! If you eat that way and have 3 small, healthy meals day and 2 small, healthy snacks, you will lose weight. Each meal should be less than 400-500 calories and each snack should be about 150-200 calories. Eating highly nutritious foods is the key; so think in terms of lean protein, veggies, whole-grains, fruits, low-fat dairy, and heart-healthy oils.
The biggest component to weight loss is going to be your workout. You will want to make sure you do a good (30 minute minimum) cardio workout every day for weight loss (3 times a week is sufficient to maintain health). Activities that use the large leg muscles burn the most calories. These activities also tone the lower body quite effectively. Think in terms of
power walking, jogging, biking, skating, swimming laps, jumping rope, dancing, racquetball, and jumping jacks. To make sure that you're burning fat, you need to be sweating and huffing and puffing.
My friend, Robin, from green-energy-efficient-homes.com wrote:
"I disagree with your assertion that there are no negative-calorie foods :) I discovered one once on a trip to the arctic:
Apparently, grizzly bears will spend hours trying to dig up a ground squirrel because they like the taste. They will excavate massive holes to dig these critters out, and they will burn way more calories than they could ever hope to get from the ground squirrel."
Thanks, Robin! I learn something new every day!