Why do we feel hungry very frequently during winter?
PRABHAT KUMAR
New Delhi
The main purpose of intake of food is to supply energy for physical needs. The body maintains a balance between energy expenditure and calorie intake which helps in proper maintenance of body weight.
The food we eat is utilized by the body by a process called metabolism (the various chemical reactions occurring in the body's cells to break down food to give us energy and heat), and this works best at normal body temperature (37ºC).
When the ambient temperature drops below certain value, the body generates heat by increasing its basal metabolic rate in order to keep up the body temperature.
There are two ways by which this metabolic feat is achieved – one, by increasing the breakdown of body's stored fat, and two, by providing the body more fuel to burn in the form of food. Alternately, you can consume more food to meet the increased metabolic demands of the body.
A part of our brain, called hypothalamus, controls this automatic regulation. The hypothalamus functions as a thermostat, and it has two discrete centers for regulating the food intake – a ‘feeding centre' and a ‘satiety centre', both of them together maintain a judicious balance of feeding behavior.
The chief factors which influence these centres are — the body weight, the amount of food present in the gut, the amount glucose in the blood and finally the body temperature.
Thus in cold weather the feeding centre is stimulated so that food intake is increased. It is worth noting here that warm weather decreases the appetite to some extent. However, ambient temperature is not a major player in regulating the food intake in human beings, whereas body weight plays a significant role.
It is interesting to note that we lose appetite in fever, because raised temperature suppresses feeding center.
DR. DHARANI KRISHNAGOPAL
Civil Surgeon Specialist, Area Hospital, Adoni, Andhra Pradesh
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