Measurement of habitual activity (Maximal Aerobic Power, MAP), fatty mass (%Fat), food intake and diastolic blood pressure (DBP) were carried out on 252 females aged 20-72 years living in suburban, rural and mountainous districts as a basic research for the prevention of essential hypertension. Measurement of MAP was made indirectly following the method of Margaria et al. Each subject screend medically was given two different intensities of step up and down exercises, and MAP was calculated from heart rates immediately after exercises and the individual\u27s estimated maximal heart rate. % Fat was estimated from skinfold thickness according to the method of Nagamine. Observation of food intake was conducted by a routine questioning, however, checks and counter checks were made by personal interviews until reliable figures had satisfactrily been obtained. Measurement of DBP was made on the right arm with subject in a seated position by automatic sphygmomanometer (BP-103, Nihon-korin Co.) and Riva-Rocci sphygmomanometer. Significant possitive correlation was found between DBP and % Fat (P＜0.01) . However, 65 percent of subjects whose DBP above 90 mmHg showed % Fat lower than 30 percent. Significant negative correlation was found between DBP and MAP (P＜0.01). However, mean DBP of active subjects in mountainous village was significantly higher than that of inactive subjects in suburban districts of city (P＜0.01) . Significant negative correlation was found between DBP and daily intake of animal fat (P＜0.01). However, significant positive correlations were found between daily intake of animal fat and that of energy, fat, protein, animal protein, calcium, iron, vitamin A, vitamin B1, vitamin B2 and vitamin C (P＜0.01, respectively) . Mean daily intake of animal fat of subjects in mountainous village was significantly lower than that of subjects in suburban districts of city (P＜0.01) . Significant negative correlation was also found between DBP and daily intake of animal protein (P＜0.01) . And mean daily intake of animal protein of subjects in mountainous village was significantly lower than that of subjects in suburban districts of city (P＜0.01). However, significant positive correlations were found between daily intake of animal protein and that of energy, fat, animal fat, protein, calcium, iron, vitamin A, vitamin B1, vitamin B2 and vitamin C (P＜0.01, respectively). Significant negative correlation was found between DBP and daily intake of sodium (P＜0.01). And the difference of sodium intake between subjects in mountainous village and subjects in suburban districts of city was not significant. However, significant positive correlations were found between daily intake of sodium and that of vitamin A (P＜0.05) and between daily intake of sodium and that of energy, fat, protein, animal protein, calcium, iron, vitamin B1, vitamin B2 and vitamin C (P＜0.01, respectively). No significant correlations were found between % Fat and animal fat intake and animal protein intake, and between MAP and animal fat intake and animal protein intake. It may be said at least in the case of subjects in this investigation that obesity or physical inactivity, low animal fat intake, low animal protein intake or malnutrition are factors of high DBP. Moreover, these results imply that different factors have to be considered according as the difference of living style for the prevention of essential hypertension
