Energy intake, anthropometry and blood pressure of expeditioners in the Antarctic

The energy intakes, anthropometry and blood pressure of 62 expeditioners at one Australian sub-Antarctic (Macquarie Island) and two Antarctic stations (Davis and Casey) were examined over a 12 month period. High mean energy intakes were found at all stations (approximately 16,000 kJ/subject/day). Mean subject body weight tended to rise during the winter months (midway during the study) and fall during the spring, although there were no significant changes (p < 0.05) seen at any of the stations over the year. Subjects were generally leaner at the end of 12 months as evidenced by significant falls (p < 0.01) in mean sum of skinfold thickness at two stations over the year. At all stations, blood pressure trended downwards during the year, with significant rises (p < 0.01) seen at one station during the spring. Two 12-week dietary intervention periods were introduced during the year at one of the Antarctic stations to investigate the effects of low-cholesterol (< 300 mg/day), low-fat (< 30% of energy) and high-fibre (> 30 g/day) diets. The average energy intake/day during these two periods (14,973 kJ and 14,515 kJ) was slightly less than during the baseline diet (average of 16,228 kJ). This was reflected in the anthropometric measurements with the mean body weight, sum of skinfold thickness and waist/hip ratios trending down during the diet periods. The study confirms earlier reports of high mean energy intake in Antarctica and suggests that the techniques of measuring intake may have been more accurate than those used in large population studies where intake may have been under-estimated. The results indicate seasonal fluctuations in blood pressure and anthropometric parameters and demonstrate that these anthropometric parameters were affected by the balance of energy intake and activity.