The average-size egg contains around 70 to 75 calories and has six grams of protein, the building block of muscle. Sounds good, so far! Not so fast, it also has 6 grams of artery clogging fat, plus 300 milligrams of cholesterol. The American Heart Association recommends that most people consume a maximum 300 milligrams of cholesterol each day. This average egg also contains 300 milligrams of sodium!