You don’t “starve” in six days. After the first 24 hours, your body goes into “economy mode”, shifting from burning glucose for energy to burning ketones. It is correct to say that the change in body chemistry does lead to much more focused thinking, but as long as sufficient water is consumed, there is little problem with toxic buildup of nitrogenous by-products. The body begins to burn, not the fat, but the muscle tissue of the body. Fat burn comes along much later in the fasting cycle, as emaciation begins to show.
When coming off a fast, consume a high-protein, low-carb diet, or all the fat will just come back on FIRST.
I’ve lost 40 pounds and reduced My A1C to 5.4 by eating one regular sized meal a day. There is an occasional snack if my sugar is trending low. But otherwise just one meal. And I’m not hungry.
CC