As we already discussed in the previous articles on apples and carrots, there are no foods that burn a net amount of calories. The whole idea of negative calorie intake is an urban legend, and you must prevent it from spreading! Therefore, questions like how many calories do you burn by eating a pear are rendered meaningless.
So exactly what will be the net effect of eating a pear? As pears are quite sweet fruits with a relatively high amount of sugar, the energy required to metabolize them account for merely a few percent of the energy they provide.
Your average pear will give you close to 100 kcal in energy. This is based on a medium sized pear, weighing around 165 grams. This translates to an energy per mass of about 58 calories per 100g. This is very low for such a sweet fruit, and is even comparable to the more bitter range of vegetables.
So you are not likely to gain weight by adding pears to your diet. In addition to their low calories, pears also contain quite a high amount of fibre, which aids in the digestion of the less healthy foods you consume throughout the day.