Basal Metabolic Rate and Energy Expenditure of Rural Farmers in Magubike Village, Kilosa District, Tanzania
Measurement of basal metabolic rate (BMR) provides an important baseline for the determination of an individual’s total energy requirement. The study sought to establish human energy expenditure of rural farmers in Magubike village in Tanzania, through determination of BMR, physical activity level (PAL) and total energy expenditure (TEE). In addition, the study intended to provide an indication of the level of energy requirement for the rural people of Tanzania. The objective of the study was to determine energy expenditure of farmers in comparison to the mean caloric intake per capita and the WHO/FAO recommended energy requirements for developing countries. A cross-sectional study design involving 33 male and 31 female farmers was conducted on randomly selected households. Basal Metabolic rate and household activities were measured by indirect calorimetry, using the Douglas bag technique. Physical activity Level was measured by twenty-four hour activity diary and TEE calculated as a product of BMR and PAL. Men’s BMR was 4.7 MJ/day while that of women was 4.3 MJ/day. Farmers mean PAL was 2.20 ± 0.25 in men and 2.05 ± 0.23 in females and TEE was 10.24 MJ/day in men and 8.57 MJ/day in women. Both BMR and TEE were higher in men than in women. The measured energy expenditure for digging and weeding were 1.57 ± 0.3 kJ/min; 1.36 ± 0.31kJ/min in men and 1.58 ± 0.3 kJ/min; 1.49 ± 0.33 kJ/min in women. It was revealed that total energy expenditure of farmers in Magubike village was high with the values being above the mean daily calorie requirement per capita for Tanzania (8.15 MJ/day) but within the WHO/FAO recommended energy requirements (11.26 MJ/day) for developing countries. High energy expenditure was attributed to high energy levels spent in farm activities which were manual and labour intensive. This is likely to be the situation in many rural areas of Tanzania. More work on measurement of costs of farm activities and farmers work capacity are necessary to provide recommendations on energy needs of rural farmers.
Key words: BMI, PAL, Anthropometry, Body composition