EFFECTS OF EATING AND NOT EATING ON ENERGY STORES AND BODY WEIGHT

Raise blood

glucose

Glucose converted

to glycogen in liver

Glycogen stored in

liver with water

Glycogen broken Water released

down to glucose from liver

(these

patterns

both

happen)

Glucose released Passed out into

into blood urine

Energy for activity Resultant apparent

rapid loss of weight

(but only water really lost)

The above flow diagram shows what happens when someone does not eat or has a very restricted diet. When that person starts to eat or to increase their intake, the diagram will flow in the opposite direction. That is, the excess glucose in the blood will be taken up into the live in combination with water and stored as glycogen. This may occur either following a binge or when someone increases their diet in a more planned way.

In either situation, a rapid increase in weight is observed (if weight is checked!) which frequently leads to further dietary restriction in order to reverse the weight gain.

Only when glycogen stores are almost exhausted does the body start to break down muscle and fat stores to release energy.

• When you look at the above diagram the left hand side gives you the energy but there is no weight loss from burning glycogen. The apparent weight loss comes from the right hand side but in fact is just water. As soon as you start to eat again the weight is rapidly regained even though you have not taken in many calories.

• The important message from this for people with eating disorders contemplating dietary changes is that the initial rate of weight gain in the first few days of change (whether up or down) will not continue.

• The other important point is that long term weight maintenance does not mean that someone's weight is the same every time they weigh themselves.

U:\Intranet pages\IP - Useful interim measures\EFFECTS OF EATING AND NOT EATING ON ENERGY STORES AND BODY WEIGHT.doc

Eat a meal

Strict diet/fast

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