Negative calorie foods are really a misnomer. It isn't possible for a food that you eat to have a negative number of calories, that's just plain impossible. What people really mean when they call something a negative calorie food is that you burn more calories eating it than the food gives you. So, on balance, you have "eaten" a negative number of calories because you've eaten, say, 20 calories and used, say, 30 calories eating it. Net result: 10 negative calories eaten.
So what sort of foods are negative calorie ones? Are they all boring foods that you wouldn't want to eat anyway?
For some of them, the answer is probably yes. You can't imagine anyone (rabbits excepted) wanting to eat a large plate of lettuce and nothing else.
But there are plenty of other negative calorie foods that might start to get you excited.
Would you like to eat a nice juicy apple? That's fine as it counts as negative calorie.
Fancy a plate of strawberries? Again, no problem. At least not until you start salivating at the thought of adding cream. But fresh strawberries with no sugar and no cream count as negative calorie. If you're on a low carb diet, they score fine for that as well.
Quite a few other fruits count as negative calorie, so you don't have to force yourself to just eat apples and strawberries. Pineapple is fine as well. So are cantaloupe melons, blackberries, raspberries and cranberries.
Just think, you could make yourself a delicious fresh fruit salad and still be on your way to losing those extra pounds.
On the veggie side, take a look at carrots. Nibbled raw they are tasty and you won't consume any extra calories. Add in some tomatoes and peppers for a colorful and tasty side salad.