According to Wikipedia, the negative effects of eating too much chocolate include addiction and excessive weight gain. Excessive chocolate consumption can also lead to diabetes, warns Science Daily. It can also depress the immune system, adds Joseph Mercola of Nourished magazine. For this reason, chocolate should be avoided during illness.
Some of the negative effects of excessive chocolate ingestion spring from the extra ingredients that manufacturers add to the product, such as sugar and fat. Eating too much chocolate increases the possibility of lead poisoning. Several studies have shown that lead can bind to cocoa shells, reports Wikipedia. Contamination may also occur when chocolate is being made.
For these reasons, Mercola encourages people to eat dark chocolate, but in moderation. Research has shown that no more than 6.7 grams of chocolate should be consumed in a day, reports Mercola. Generally, dark chocolate undergoes minimal processing and contains little in the way of potentially harmful extra ingredients, such as sugar. It is also less likely to be contaminated with lead. In addition, dark chocolate contains antioxidants known as flavonols, which protect the body from damage caused by oxidants. According to Mercola, dark chocolate improves the metabolization of glucose and helps maintain the correct blood pressure.