Everybody has bad eating habits like snacking excessively at work or drinking beer at night. Some common midnight snacks include devil's food cake, cheese, and salami. Poor nutrition can stem from diseases or conditions like celiac disease and lead to deficiencies. Iron deficiency is the most widespread form of malnutrition globally. Deficiencies can cause health issues depending on which nutrients are missing, like vitamin D deficiency drawing calcium from bones and causing fractures. The best way to ensure good nutrition is eating a varied diet with plenty of fruits and vegetables, whole grains, and lean meats prepared in healthy ways like baking instead of frying.