In studies which have investigated the normal changes in body weight in healthy, free-living individuals, a fluctuation of + 1 kg in consecutive days is common, and fluctuations of + 0.5 kg are very common.
In order to understand the reasons for these variations in body weight during short periods it is worth considering the various components of the human body which can change in size and thus result in changes in weight.

 

Component of Human Body	Tissue Type	Daily Changes in Weight When Eating a Normal Diet	Rate of Change in Weight When Dieting
Structural	Bones, ligaments, cartilages etc	None	No change
Major energy reserves	Muscle, fat	None	Changes occur slowly over several weeks of dieting
Short term energy reserves	Glycogen (stored in combination with water in the liver)	Minimal fluctuations of 0.5 - 1.0 kg are common	Is responsible for initial rapid loss of weight in first few days of dieting

 

Although loss of mineral from the bones is a common side effect of starvation, the effects of this on body weight are small.

The body's glycogen stores are specifically designed to provide energy in the short term, i.e. between meals, and in normal circumstances they only last for a few hours.

Published: 09/10/2020 10:30