We are all very concerned about what we eat. We try to follow recommendations to get adequate servings of fruits and vegetables in our diet; we cut back on the fatty foods and buy foods that are less processed. However, even though there is more emphasis on what we eat, a large proportion of the population of the western - industrialized countries is overweight and diet related diseases kill people every year.
Nutritionists are concerned about what we eat, but recently there has been a growing interest in when and how often we eat. Perhaps the traditional three meals a day is not the best for us. If you examine food consumption in different cultures, there are often very different patterns. In some cultures the "big meal of the day" is in the evening. In some countries breakfast is a large meal and in yet other countries the main meal of the day occurs at mid-day. Some of these differences may be related to culture, and some to climate. It probably is more comfortable to prepare and eat a big meal before the hottest part of the day.
But what about the idea of a fourth meal? In some cultures food consumption is spread over four rather than three meals. The British have their "high tea", in the Philippines there is the merienda. Many people enjoy a snack in the middle of the afternoon. Does this make sense in terms of your health?
It is a well known fact that, when experimental animals (rats) are fed "meals" rather than allowed to "nibble", they gain weight. This occurs even when the total amount of food consumed per day is kept the same. This difference is explained by a change in metabolism that occurs when animals eat meals. It seems that the body recognizes that a meal will be followed by a period of fasting and so, to ensure adequate energy until the next meal, it stores fat. The fat can be called upon until the next meal.
Humans who go from a meal pattern to a binge pattern of food consumption experience large increases in insulin levels and increased blood glucose levels - again indicating that the body is trying to adjust to the long periods in between feeding. Increasing the number of meals per day has been suggested as a way of combating constipation, and has also been recommended for school aged children. There also has been speculation that increasing the number of meals a day (but not snacks) reduces the risk of colon cancer.
The important thing to remember is that the amount of calories consumed needs to remain constant. If the fourth meal consists of foods high in calories in general and fat in particular, then the extra calories will be stored as fat. The idea of a fourth meal is to spread the intake of food over the day. If this is done, body weight may be easier to regulate, and weight loss may occur.