Investigating Human Energy Metabolism

Obesity occurs when the energy intake from food (energy intake) exceeds the energy expended in daily activities or exercise (energy expenditure). To reduce obesity, people with excess body weight need to reduce their calorie intake from food, or increase exercise or basal metabolic rate.

The basal metabolic rate declines with age, so we focused on the inherent metabolic functions of humans and carried out research on energy metabolism. The goal is finding ways to prevent or improve the accumulation of fat.

Using a human calorimeter, a device in the form of a room to analyze metabolism by measuring the concentrations of O₂ and CO₂ in the air, we investigated the energy metabolism of humans in various situations.
For example, we found that short sleep influences the energy balance not due to an effect on energy expenditure but due to an effect on appetite^*1 . In addition, we were able to show that brown fat, which was thought to exist only in small animals or human infants, affects energy expenditure and fat oxidation in daily life also in human adults^*2 .

Kao will continue its research on the true natural state of human metabolism, and through its research activities and product development, work towards offering new solutions and products.