The body must have fuel to survive. The Atkins diet hopes the body will use its fat cells for fuel. When it does, the byproducts from the fat, called ketones, break down, enter the bloodstream and cause ketosis to set in. Ketosis suppresses hunger. Ketosis can also cause nausea, fatigue, lightheadedness and dangerous fluid loss.
Ketones make blood more acidic.
In order to help neutralize this high acidity, registered dietitian Elizabeth Ward says, calcium is shifted out of the long bones and sent to the bloodstream. This shift predisposes the bones to osteoporosis, and the body to calcium depletion. The body doesn't always use its fat cells for fuel. Sometimes it uses the body's protein, which it may metabolize by breaking down muscle and lean tissue. If kidneys are compromised in any way, the Atkins diet may trigger severe renal problems.