First, remember that as a society, our dietary habits have changed over the past couple of generations. A healthy diet consists of plenty of fruits and vegetables and whole grains. Recent studies indicate that the majority of meals in the US are eaten in restaurants rather than in the home. Restaurant food tends to be too high in fat and sugar. Additionally, convenience foods now make up a much higher percentage of the average diet than in the past. In some people well over 60% of their food is from so-called "empty" calorie foods (candy, sweets, chips, or other highly processed foods that contain very little real nutritional value other than calories). Another factor is the high stresses found in today's fast-paced and busy life. The greater the external stresses, the higher the nutritional demands on the body. Eating a poor-quality diet robs you of the nutritional factors necessary to help you stay healthy. Lastly, many people are simply unaware of how to shop for healthy foods. Convenience and taste become the major criteria for food selection, while nutritional value is given little attention, if any at all. Many nutritional researchers point to the rising problems of obesity, diabetes, heart disease and other diseases of modern society as evidence of the deteriorating quality of the diet most people consume.