Very low calorie diet
) is a diet
with very or extremely
consumption per day. It is defined medically as a diet of 800 kilocalories
per day or less. VLCDs are formulated, nutritionally
complete, liquid meals
containing 3350 kJ
) or less per day. VLCDs also contain the recommended daily requirements for vitamins
, trace elements
, fatty acids
. The VLCD products are usually a powder which is mixed with water
or another low calorie liquid.
Because of the extremely low calories per day, a VLCD diet cannot be used by children no matter how obese.
A VLCD should never be undertaken without medical supervision.
study concludes that the short-term use of a VLCD is very effective in rapidly improving glycaemic
control and promoting substantial weight loss
in obese patients with Type 2 diabetes
. Moreover, a VLCD increases insulin
sensitivity and reduces the substrate for gluconeogenesis
. Thus VLCD treatment may improve glycaemic control more than calorie restriction
The risk of gallbladder
disease is greatly increased for individuals following a VLCD.
Another potential side effect is constipation (depending on the fibre content of the diet).