Breakfast is the first meal of the day. The word is a compound of "break" and "fast," referring to the conclusion of fasting since the previous day's last meal. Breakfast meals vary widely in different cultures around the world but often include a carbohydrate such as cereal or rice, fruit and/or vegetable, protein, sometimes a dairy product, and a drink. Nutritional experts have referred to breakfast as the most important meal of the day. This is based on studies of the large numbers of people in the West who skip breakfast, to adverse effect on their concentration, metabolism and weight.