Exercise and nutrition are absolutely necessary for health promotion or enhancing athletic performance. On the other hand, physical activities and food situation affect nutritional status and physiological function.   In Japan, exercise induced anemia (sports anemia) was observed in the late 1950′s., and this symptom was improved by increasing dietary total protein and⁄or animal protein intake levels. Nowadays, protein fat carbohydrate ratio is approximately 15:25:60 which is suggested for athletes. In case of maintaining body weight, the dietary method of increasing all foods in proportion to the energy intake seems to be suitable. Body weight reduction by exercise is more effective than by dietary restriction even when dietary condition is equal except for energy.   It is well known that prolonged bed rest or weightlessness cause various atrophies and decreasing physiological function. After the Great East Japan Earthquake, disuse syndrome under worsened food situation happened as well as after previous earthquakes. In these cases, relatively-frequent physical activities are recommended than relatively- large amount of exercise.   Recently in the world, there are some problems such as double burden of malnutrition in developing countries and obesity people who consume too much junk food or soft drinks, etc. In response to becoming diversified lifestyles, it is considered that roles of eating habits and physical activities will be more important.