Originally Posted by Koshka
No your body won't just shut down and you won't lose anything. Think about it. If that was true, people would never starve to death! But, in fact, they do.
My understanding, however, is that if you eat very low calories your metabolism may slow somewhat. You would still lose weight though. If someone is really and truly eating 950 calories a day, each and every day, and never eating more than that and is a normal person without illness who moves around normally during the day -- that person will lose weight.
So one of these things is most likely to be true if someone actually does think their body has shut down due to eating low calorie (I'm not saying this is actually your situation, just responding to the point):
1. The person is eating more than they think they are. Most people are very inaccurate at estimating calories eaten. Have then been weighing all their food and recording all of it immediately upon eating? If not, try doing that for awhile.
2. Sometimes people don't recognize the impact of 1 or 2 high calorie days. They eat 950 calories most days but then have a day they eat 2500 calories. They have to count those extra calories.
3. If really and truly eating 950 calories each and every day and they aren't losing weight - then maybe they need to get checked out by a physician.
I like this article about Starvation Mode:
I think these are good points. What I learned from my diet coach (for which I have no links to research) is that 2 things might happen on a very restricted diet: 1) weight loss SLOWS but does not stop. The point is that if you are restricting severely in order to experience the most rapid weight loss, there ight be a middle ground of calories--low enough to lose but high enough and with appropriate nutrients to maintain metabolism.
2) Your body needs a certain amount of glucose. The two sources for glucose that the body is equipped to use are carbohydrates & proteins, but NOT fat. The liver will digest your own muscle if needed, to get protein to convert to glucose.
The down side of that regarding weight loss is that muscle tissue plays a role in maintaining weight loss, as it requires energy just to maintain itself. The more muscle mass, the more energy we burn just by being alive.