> 1200 calories at least to stop your body from using muscle for sustenance.
This is only true up to a point. A colleague put me onto a fasting method called “Buchinger’s Fasting”. I fasted for around a week and a half, muscle maintenance was not a concern. After 3 days, your body burns through the glucose reserves and you get brain fog. After that, indeed, your body tried to break down muscle mass for fuel. The trick is to do some moderate exercise to keep your muscles in good condition. After a few days, your body finally turns to your fat reserves, and rapidly starts burning away fat. After the first 3 or so days, you actually become numb to the hunger and go into a slightly “high”, hunter gatherer alert mode that enabled our ancestors to search for food when hungry. It really brings home that being hungry and not being fed constantly is a normal part of human existence, and the industrial era, shoving food down our gullets constantly is making us sick and prevents natural healing within our bodies.
I assume that is from Buchinger Clinic in Germany? I watched a documentary (can’t remember the name) about fasting that claims it is more commonplace in Europe than elsewhere. They also claimed the Soviets studied it for years with favorable results.
Yeah it's from Germany. I can personally attest to its effectiveness. Another colleague who is approaching retirement does it twice per year or so, and he's in great shape and looks great for his age. It was very eye-opening to see that and then to experience it.
This aligns exactly with my experience. The body is very reluctant to turn into fat reserves, as they the best source of energy and must be conserved. As you said, exercise helps, and another trick to eat some carbs every three or so days to convince your body to start burning fat.
Presumably by giving the signal that "food is available" and the system can break out of the hypocaloric energy preservation state. The problem is that the fat deposits are extremely valuable (in a non overweight person) and as one enters a hypocaloric state they become more valuable. I.e your body will rather throttle down metabolism and energy levels farther than start breaking down the fat for energy. Eating some carbs can healp to break this pattern.
I don't think the body works like that. After you eat carbs, your insulin level goes up and the cells get the glucose in them. If there's more than they can take, it is put into the adipose tissue as fat. Eating carbs once every 3 days is in no way telling the body that there is enough food, quite the contrary actually (all this is just my opinion).
This carb refeed reset "tricks" your leptide hormones to burning through energy reserves rather than putting the body through a catatonic (muscle burning) state. This is why the "Cheat" meal or day is an important step to sustaining body fat loss through elongated periods.
