How dietary restraint and refeeding affect the body
- Initial weight loss is due to the loss of glucose solution stored in the muscles.
- If food intake is still insufficient to meet energy demands, then fat reserves will be broken down.
- The body cannot break fat down fast enough, so muscle is broken down as well.
- Metabolic rate (which is linked to amount of muscle) will fall.
- Also if gaps between meals are longer than 3 hours, metabolic rate will fall.
- If a person is eating very little, their body will adapt in a number of ways to conserve and utilise the energy resources available:
The metabolic rate, heart and breathing rates will all decrease.
Low metabolic rate means a low weight can only be maintained by eating very little.
Stomach emptying will be slower, so that food remains there longer.
- Starvation triggers release of endorphins which give a morphine-like 'high', a feel good factor which goes when people start eating again.
- During refeeding, stores of fat and glucose solution are replenished first, with fat being deposited on the hips and stomach. This is then gradually converted into muscle and redistributed, but there can be a temporary feeling of bloatedness, which is uncomfortable and disconcerting for "dieters".
- Being deprived of food sets up cravings and binges are then likely to occur. Also, in 'famine mode' extra fat is stored when food becomes available.
Each person has an inbuilt weight regulating system, involving
many factors such as metabolic rate and hormone balance to keep weight within a set point
weight range (generally a few kilos/half a stone) which is predetermined by the genetic blue print.