No.
A piece of 40 grams of chocolate contains about 210 calories, while the human body must be 2000 calories per day, that is, only one-tenth of the amount, is not enough to make the body fat.
Expanded:
Other misconceptions about chocolate:
Myth No. 2: Chocolate is a sugary food with no nutritional value
Fact: Chocolate is actually is an extremely nutritious sugary food, and chocolate provides a significant amount of the nutrients that the human body needs on a daily basis. Just 1.4 ounces (about 40 grams) of milk chocolate contains 3 grams of protein, 15% of the body's daily vitamin B2 needs, 9% calcium, 7% iron, 9% phosphorus, 6% magnesium, and 8% copper, and even more zinc, potassium, and anti-mangement vitamins than are found in regular milk.
If your children are particularly fond of sweets, chocolate will be a very wise choice, because it is definitely more nutritious than other sugary foods, and can satisfy children's cravings.
Source: International Cocoa Organization (ICCO), International Food Information Council (IFIC), Human Nutrition Information Service (HNIS)
Myth No. 3: Eating Chocolate Causes Tooth Decay
Facts: Sugar in any food, if it stays in your mouth for a long time, will cause the risk of various dental diseases, and chocolate is no exception. But chocolate contains a natural ingredient that resists the acids in sugar that tend to destroy the dental bed and cause tooth decay. And the protein, calcium, phosphate and other minerals contained in chocolate's cocoa butter have a significant protective effect on the dental bed, slowing down the formation of plaque. Furthermore, the sugar in chocolate dissolves faster in the mouth than sugar in any other food, so the effect of consuming chocolate on the formation of cavities is relatively much less than consuming any other sugary food.
Source: FORSYTH Dental Center, Boston; University of Pennsylvania School of Dental Medicine.
Myth No. 4: Eating Chocolate Causes Acne
Fact: Eating chocolate neither causes nor aggravates acne, and acne is not initially caused by any diet.
References: